From dcc2b65627acfae4a954b8020d961ccb598c2fb9 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sun, 15 Sep 2024 20:33:33 -0600
Subject: [PATCH 01/23] add lEEt/OS

thanks @SuperMaxusa
---
 src/browser/main.js | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/browser/main.js b/src/browser/main.js
index 186b0a0a96..0fe6fa2b73 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -1195,6 +1195,7 @@
                 cdrom: {
                     url: host + "nanoshell.iso",
                     size: 6785024,
+                    async: false,
                 },
                 homepage: "https://github.com/iProgramMC/NanoShellOS",
             },
@@ -1204,6 +1205,7 @@
                 cdrom: {
                     url: host + "catkernel.iso",
                     size: 11968512,
+                    async: false,
                 },
                 homepage: "https://catk.neocities.org/",
             },
@@ -1224,6 +1226,15 @@
                     size: 368640,
                 },
             },
+            {
+                id: "leetos",
+                name: "lEEt/OS",
+                fda: {
+                    url: host + "leetos.img",
+                    size: 1474560,
+                },
+                homepage: "http://sininenankka.dy.fi/leetos/index.php",
+            },
         ];
 
         if(DEBUG)

From ca8649f38ec7406f9bec464e72ec6332428d7524 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sun, 15 Sep 2024 22:11:52 -0600
Subject: [PATCH 02/23] mention --disable-web-security for browsing in fetch
 mode

---
 docs/networking.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/docs/networking.md b/docs/networking.md
index 8a1a51585b..401efe6ee3 100644
--- a/docs/networking.md
+++ b/docs/networking.md
@@ -29,6 +29,12 @@ hosts). Additionally, NTP, ICMP pings and UDP echo packets are handled to a
 certain degree. See [#1061](https://github.com/copy/v86/pull/1061) for some
 technical details.
 
+You can pass the following flags to chromium to allow browsing without
+restrictions in `fetch` mode:
+    `--disable-web-security --user-data-dir=/tmp/test`
+Note that this turns off the same-origin policy and should only be used
+temporarily.
+
 ### wisp networking
 
 v86 also supports the [wisp

From 808256f0b7302fcd21280b0c15c14b5be9b2cca4 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sun, 15 Sep 2024 22:14:59 -0600
Subject: [PATCH 03/23] add NewOS

thanks @SuperMaxusa
---
 src/browser/main.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/browser/main.js b/src/browser/main.js
index 0fe6fa2b73..857f0b3329 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -1235,6 +1235,16 @@
                 },
                 homepage: "http://sininenankka.dy.fi/leetos/index.php",
             },
+            {
+                id: "newos",
+                name: "NewOS",
+                fda: {
+                    url: host + "newos-flp.img",
+                    size: 1474560,
+                    async: false,
+                },
+                homepage: "https://newos.org/",
+            },
         ];
 
         if(DEBUG)

From 662cd067f4df2f7f3c4717e159e45a5dc1e95c93 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sun, 15 Sep 2024 22:27:34 -0600
Subject: [PATCH 04/23] add tinyaros/aros-broadway/icaros

thanks @SuperMaxusa
---
 src/browser/main.js | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/src/browser/main.js b/src/browser/main.js
index 857f0b3329..9f30780b90 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -1245,6 +1245,46 @@
                 },
                 homepage: "https://newos.org/",
             },
+            {
+                id: "aros-broadway",
+                name: "AROS Broadway",
+                memory_size: 512 * 1024 * 1024,
+                cdrom: {
+                    url: host + "broadway10/.iso",
+                    size: 742051840,
+                    async: true,
+                    fixed_chunk_size: 512 * 1024,
+                    use_parts: true,
+                },
+                homepage: "https://web.archive.org/web/20231109224346/http://www.aros-broadway.de/",
+            },
+            {
+                id: "icaros",
+                name: "Icaros Desktop",
+                memory_size: 512 * 1024 * 1024,
+                cdrom: {
+                    url: host + "icaros-pc-i386-2.3/.iso",
+                    size: 726511616,
+                    async: true,
+                    // NOTE: needs 136MB/287 requests to boot, maybe state image or zst parts?
+                    fixed_chunk_size: 512 * 1024,
+                    use_parts: true,
+                },
+                homepage: "http://vmwaros.blogspot.com/",
+            },
+            {
+                id: "tinyaros",
+                name: "Tiny Aros",
+                memory_size: 512 * 1024 * 1024,
+                cdrom: {
+                    url: host + "tinyaros-pc-i386/.iso",
+                    size: 111175680,
+                    async: true,
+                    fixed_chunk_size: 512 * 1024,
+                    use_parts: true,
+                },
+                homepage: "https://www.tinyaros.it/",
+            },
         ];
 
         if(DEBUG)

From 63883143de3f1b23ff89599fd36d06ffc2c17e64 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Mon, 16 Sep 2024 00:38:05 -0600
Subject: [PATCH 05/23] remove dead profile

---
 debug.html | 1 -
 1 file changed, 1 deletion(-)

diff --git a/debug.html b/debug.html
index c2054197ec..2a06ae9cce 100644
--- a/debug.html
+++ b/debug.html
@@ -72,7 +72,6 @@
         <h4>Debugger</h4>
         <input type="button" value="ReactOS" id="start_reactos">
         <input type="button" value="ReactOS (boot)" id="start_reactos-boot">
-        <input type="button" value="Hiren's Boot CD" id="start_hirens">
         <br>
 
         <input type="button" value="MS-DOS" id="start_msdos">

From 12cfffdc40db1fc91ff4b5ef8616fba388b90a5c Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Wed, 18 Sep 2024 16:58:23 -0600
Subject: [PATCH 06/23] update readme

---
 Readme.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Readme.md b/Readme.md
index 3ef101304d..02eeaed549 100644
--- a/Readme.md
+++ b/Readme.md
@@ -208,6 +208,7 @@ repository under their own licenses:
 - [The jor1k project](https://github.com/s-macke/jor1k) for 9p, filesystem and uart drivers
 - [WinWorld](https://winworldpc.com/) sources of some old operating systems
 - [OS/2 Museum](https://www.os2museum.com/) sources of some old operating systems
+- [ArchiveOS](https://archiveos.org/) sources of several operating systems
 
 ## More questions?
 

From 92b5f82928fab90d944f49e9a550353595425380 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Wed, 18 Sep 2024 18:45:38 -0600
Subject: [PATCH 07/23] update helenos to 0.14.1

---
 src/browser/main.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/browser/main.js b/src/browser/main.js
index 9f30780b90..965c9a17c8 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -311,8 +311,10 @@
                 id: "helenos",
                 memory_size: 256 * 1024 * 1024,
                 cdrom: {
-                    url: host + "HelenOS-0.11.2-ia32.iso",
-                    size: 25765888,
+                    //url: host + "HelenOS-0.11.2-ia32.iso",
+                    //size: 25765888,
+                    url: host + "HelenOS-0.14.1-ia32.iso",
+                    size: 25792512,
                     async: false,
                 },
                 name: "HelenOS",

From 8e768e8630038ff040020b1e4d82ecc9de955776 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Wed, 18 Sep 2024 19:19:55 -0600
Subject: [PATCH 08/23] tests: increase timeout

---
 tests/full/run.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/full/run.js b/tests/full/run.js
index ae4a906a2b..744cadc827 100755
--- a/tests/full/run.js
+++ b/tests/full/run.js
@@ -799,7 +799,7 @@ if(cluster.isMaster)
         {
             name: "Crazierl",
             skip_if_disk_image_missing: true,
-            timeout: 30,
+            timeout: 60,
             memory_size: 256 * 1024 * 1024,
             multiboot: root_path + "/images/crazierl-elf.img",
             initrd: root_path + "/images/crazierl-initrd.img",

From ee0805c343340f4008d83390e578583e67a99af8 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Wed, 18 Sep 2024 23:27:25 -0600
Subject: [PATCH 09/23] add some bootsector games/demos (bootrogue, dino,
 tetros, bootlogo)

suggested by @SuperMaxusa
---
 src/browser/main.js | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/browser/main.js b/src/browser/main.js
index 965c9a17c8..66ce83b594 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -675,11 +675,20 @@
                 id: "bootbasic",
                 fda: {
                     url: host + "bootbasic.img",
-                    size: 1474560,
+                    size: 512,
                 },
                 name: "bootBASIC",
                 homepage: "https://github.com/nanochess/bootBASIC",
             },
+            {
+                id: "bootlogo",
+                fda: {
+                    url: host + "bootlogo.img",
+                    size: 512,
+                },
+                name: "bootLogo",
+                homepage: "https://github.com/nanochess/bootLogo",
+            },
             {
                 id: "sectorlisp",
                 fda: {
@@ -724,6 +733,33 @@
                 },
                 name: "Hello v86",
             },
+            {
+                id: "tetros",
+                fda: {
+                    url: host + "tetros.img",
+                    size: 512,
+                },
+                name: "TetrOS",
+                homepage: "https://github.com/daniel-e/tetros",
+            },
+            {
+                id: "dino",
+                fda: {
+                    url: host + "bootdino.img",
+                    size: 512,
+                },
+                name: "dino",
+                homepage: "https://github.com/franeklubi/dino",
+            },
+            {
+                id: "bootrogue",
+                fda: {
+                    url: host + "bootrogue.img",
+                    size: 512,
+                },
+                name: "bootRogue",
+                homepage: "https://github.com/nanochess/bootRogue",
+            },
             {
                 id: "duskos",
                 hda: {

From 8f79a11cd8da288b7104bdc424a4d9641552a074 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 16:16:35 -0600
Subject: [PATCH 10/23] javascript should be made as simple as possible, but
 not simpler

---
 debug.html | 113 ++++++++++++++++++++++++-----------------------------
 1 file changed, 52 insertions(+), 61 deletions(-)

diff --git a/debug.html b/debug.html
index 2a06ae9cce..3caf306b7a 100644
--- a/debug.html
+++ b/debug.html
@@ -4,67 +4,58 @@
 <title>Virtual x86 (debug)</title>
 <meta name="viewport" content="width=device-width,minimum-scale=1.0,maximum-scale=1.0,user-scalable=no">
 
-<script>
-"use strict";
-
-var CORE_FILES =
-    "const.js config.js log.js lib.js buffer.js cpu.js debug.js " +
-    "io.js main.js ide.js pci.js floppy.js " +
-    "memory.js dma.js pit.js vga.js ps2.js rtc.js uart.js acpi.js apic.js ioapic.js sb16.js " +
-    "ne2k.js state.js virtio.js virtio_console.js virtio_net.js bus.js elf.js kernel.js";
-
-var BROWSER_FILES = "main.js screen.js keyboard.js mouse.js speaker.js serial.js network.js fake_network.js fetch_network.js wisp_network.js starter.js worker_bus.js print_stats.js filestorage.js";
-var LIB_FILES = "";
-
-// jor1k stuff
-LIB_FILES += " jor1k.js 9p.js filesystem.js marshall.js";
-
-var BUILD_FILES = "capstone-x86.min.js libwabt.js";
-
-var to_load = [];
-
-load_scripts(CORE_FILES, "src/");
-load_scripts(BROWSER_FILES, "src/browser/");
-load_scripts(LIB_FILES, "lib/");
-load_scripts(BUILD_FILES, "build/");
-
-function load_scripts(resp, path)
-{
-    var files = resp.split(" ");
-
-    for(var i = 0; i < files.length; i++)
-    {
-        if(!files[i])
-        {
-            continue;
-        }
-
-        to_load.push(path + files[i]);
-    }
-}
-
-load_next();
-
-function load_next()
-{
-    let s = to_load.shift();
-
-    if(!s)
-    {
-        return;
-    }
-
-    var script = document.createElement("script");
-    script.src = s;
-    script.onload = load_next;
-    script.onerror = function() {
-        console.warn("trying to ignore script " + s + ", which failed to load");
-
-        load_next();
-    };
-    document.head.appendChild(script);
-}
-</script>
+<script src="src/const.js"></script>
+<script src="src/config.js"></script>
+<script src="src/log.js"></script>
+<script src="src/lib.js"></script>
+<script src="src/buffer.js"></script>
+<script src="src/cpu.js"></script>
+<script src="src/debug.js"></script>
+<script src="src/io.js"></script>
+<script src="src/main.js"></script>
+<script src="src/ide.js"></script>
+<script src="src/pci.js"></script>
+<script src="src/floppy.js"></script>
+<script src="src/memory.js"></script>
+<script src="src/dma.js"></script>
+<script src="src/pit.js"></script>
+<script src="src/vga.js"></script>
+<script src="src/ps2.js"></script>
+<script src="src/rtc.js"></script>
+<script src="src/uart.js"></script>
+<script src="src/acpi.js"></script>
+<script src="src/apic.js"></script>
+<script src="src/ioapic.js"></script>
+<script src="src/sb16.js"></script>
+<script src="src/ne2k.js"></script>
+<script src="src/state.js"></script>
+<script src="src/virtio.js"></script>
+<script src="src/virtio_console.js"></script>
+<script src="src/virtio_net.js"></script>
+<script src="src/bus.js"></script>
+<script src="src/elf.js"></script>
+<script src="src/kernel.js"></script>
+<script src="src/browser/main.js"></script>
+<script src="src/browser/screen.js"></script>
+<script src="src/browser/keyboard.js"></script>
+<script src="src/browser/mouse.js"></script>
+<script src="src/browser/speaker.js"></script>
+<script src="src/browser/serial.js"></script>
+<script src="src/browser/network.js"></script>
+<script src="src/browser/fake_network.js"></script>
+<script src="src/browser/fetch_network.js"></script>
+<script src="src/browser/wisp_network.js"></script>
+<script src="src/browser/starter.js"></script>
+<script src="src/browser/worker_bus.js"></script>
+<script src="src/browser/print_stats.js"></script>
+<script src="src/browser/filestorage.js"></script>
+<script src="lib/jor1k.js"></script>
+<script src="lib/9p.js"></script>
+<script src="lib/filesystem.js"></script>
+<script src="lib/marshall.js"></script>
+<script src="build/capstone-x86.min.js"></script>
+<script src="build/libwabt.js"></script>
+
 <link rel="stylesheet" href="v86.css">
 
 <div>

From c3aaf7afdfa6c7ce74fa9907cc2e59de6881cfc4 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 16:41:12 -0600
Subject: [PATCH 11/23] dead code

---
 src/lib.js | 26 --------------------------
 1 file changed, 26 deletions(-)

diff --git a/src/lib.js b/src/lib.js
index 71bb7f3a44..3fd01a6c3b 100644
--- a/src/lib.js
+++ b/src/lib.js
@@ -160,19 +160,6 @@ else
     if(typeof Math.clz32 === "function" && Math.clz32(0) === 32 &&
        Math.clz32(0x12345) === 15 && Math.clz32(-1) === 0)
     {
-        /**
-         * calculate the integer logarithm base 2 of a byte
-         * @param {number} x
-         * @return {number}
-         */
-        v86util.int_log2_byte = function(x)
-        {
-            dbg_assert(x > 0);
-            dbg_assert(x < 0x100);
-
-            return 31 - Math.clz32(x);
-        };
-
         /**
          * calculate the integer logarithm base 2
          * @param {number} x
@@ -198,19 +185,6 @@ else
         int_log2_table[i] = b;
     }
 
-    /**
-     * calculate the integer logarithm base 2 of a byte
-     * @param {number} x
-     * @return {number}
-     */
-    v86util.int_log2_byte = function(x)
-    {
-        dbg_assert(x > 0);
-        dbg_assert(x < 0x100);
-
-        return int_log2_table[x];
-    };
-
     /**
      * calculate the integer logarithm base 2
      * @param {number} x

From 97d392cdbbb7c34907d491986039e775906dd4ca Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 16:57:06 -0600
Subject: [PATCH 12/23] add v86util.round_up_to_next_power_of_2 and some tests

---
 src/lib.js | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/lib.js b/src/lib.js
index 3fd01a6c3b..f9cf669cb6 100644
--- a/src/lib.js
+++ b/src/lib.js
@@ -157,8 +157,7 @@ else
 
 (function()
 {
-    if(typeof Math.clz32 === "function" && Math.clz32(0) === 32 &&
-       Math.clz32(0x12345) === 15 && Math.clz32(-1) === 0)
+    if(typeof Math.clz32 === "function" && Math.clz32(0) === 32 && Math.clz32(0x12345) === 15 && Math.clz32(-1) === 0)
     {
         /**
          * calculate the integer logarithm base 2
@@ -225,6 +224,27 @@ else
     };
 })();
 
+v86util.round_up_to_next_power_of_2 = function(x)
+{
+    dbg_assert(x >= 0);
+    return x <= 1 ? 1 : 1 << 1 + v86util.int_log2(x - 1);
+};
+
+if(DEBUG)
+{
+    dbg_assert(v86util.int_log2(1) === 0);
+    dbg_assert(v86util.int_log2(2) === 1);
+    dbg_assert(v86util.int_log2(7) === 2);
+    dbg_assert(v86util.int_log2(8) === 3);
+    dbg_assert(v86util.int_log2(123456789) === 26);
+
+    dbg_assert(v86util.round_up_to_next_power_of_2(0) === 1);
+    dbg_assert(v86util.round_up_to_next_power_of_2(1) === 1);
+    dbg_assert(v86util.round_up_to_next_power_of_2(2) === 2);
+    dbg_assert(v86util.round_up_to_next_power_of_2(7) === 8);
+    dbg_assert(v86util.round_up_to_next_power_of_2(8) === 8);
+    dbg_assert(v86util.round_up_to_next_power_of_2(123456789) === 134217728);
+}
 
 /**
  * @constructor

From 0bc1008c93cf29b964c1870e4c1c9b62ab9434ce Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 17:04:14 -0600
Subject: [PATCH 13/23] round vga memory size up to next power of 2

---
 src/vga.js | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/src/vga.js b/src/vga.js
index 928b77d847..c8afcff402 100644
--- a/src/vga.js
+++ b/src/vga.js
@@ -206,6 +206,21 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
     this.svga_offset_x = 0;
     this.svga_offset_y = 0;
 
+    if(this.vga_memory_size === undefined || this.vga_memory_size < VGA_MIN_MEMORY_SIZE)
+    {
+        this.vga_memory_size = VGA_MIN_MEMORY_SIZE;
+    }
+    else if(this.vga_memory_size > VGA_MAX_MEMORY_SIZE)
+    {
+        this.vga_memory_size = VGA_MAX_MEMORY_SIZE;
+    }
+    else
+    {
+        // required for pci code
+        this.vga_memory_size = v86util.round_up_to_next_power_of_2(this.vga_memory_size);
+    }
+    dbg_log("effective vga memory size: " + this.vga_memory_size, LOG_VGA);
+
     const pci_revision = 0; // set to 2 for qemu extended registers
 
     // Experimental, could probably need some changes
@@ -220,7 +235,7 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
     this.pci_id = 0x12 << 3;
     this.pci_bars = [
         {
-            size: vga_memory_size,
+            size: this.vga_memory_size,
         },
     ];
 
@@ -339,23 +354,6 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
     io.register_write(0x1CF, this, undefined, this.port1CF_write);
     io.register_read(0x1CF, this, undefined, this.port1CF_read);
 
-    if(this.vga_memory_size === undefined || this.vga_memory_size < VGA_MIN_MEMORY_SIZE)
-    {
-        this.vga_memory_size = VGA_MIN_MEMORY_SIZE;
-        dbg_log("vga memory size rounded up to " + this.vga_memory_size, LOG_VGA);
-    }
-    else if(this.vga_memory_size > VGA_MAX_MEMORY_SIZE)
-    {
-        this.vga_memory_size = VGA_MAX_MEMORY_SIZE;
-        dbg_log("vga memory size rounded down to " + this.vga_memory_size, LOG_VGA);
-    }
-    else if(this.vga_memory_size & (VGA_BANK_SIZE - 1))
-    {
-        // round up to next 64k
-        this.vga_memory_size |= VGA_BANK_SIZE - 1;
-        this.vga_memory_size++;
-    }
-
 
     const vga_offset = cpu.svga_allocate_memory(this.vga_memory_size) >>> 0;
     this.svga_memory = v86util.view(Uint8Array, cpu.wasm_memory, vga_offset, this.vga_memory_size);

From 49865ebbc606dc7cc57db6f6ec6a3e7fc9cc5f02 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 17:09:15 -0600
Subject: [PATCH 14/23] refactor frontpage loading of profiles

---
 debug.html          |   4 +-
 index.html          |   4 +-
 src/browser/main.js | 712 +++++++++++++++++++-------------------------
 3 files changed, 305 insertions(+), 415 deletions(-)

diff --git a/debug.html b/debug.html
index 3caf306b7a..6fd6fa46fa 100644
--- a/debug.html
+++ b/debug.html
@@ -127,9 +127,9 @@ <h4>Debugger</h4>
 
         <table>
             <tr>
-                <td width="350"><label for="cd_image">CD image</label></td>
+                <td width="350"><label for="cdrom_image">CD image</label></td>
                 <td>
-                    <input type="file" id="cd_image">
+                    <input type="file" id="cdrom_image">
                 </td>
             </tr>
 
diff --git a/index.html b/index.html
index 271193b3fc..05da552de8 100644
--- a/index.html
+++ b/index.html
@@ -70,9 +70,9 @@ <h4>Select profile</h4>
         <h4>Setup</h4>
         <table>
             <tr>
-                <td width="350"><label for="cd_image">CD image</label></td>
+                <td width="350"><label for="cdrom_image">CD image</label></td>
                 <td>
-                    <input type="file" id="cd_image">
+                    <input type="file" id="cdrom_image">
                 </td>
             </tr>
 
diff --git a/src/browser/main.js b/src/browser/main.js
index 66ce83b594..49ec5a33eb 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -2,25 +2,7 @@
 
 (function()
 {
-    /** @const */
-    var ON_LOCALHOST = !location.hostname.endsWith("copy.sh");
-
-    /**
-     * @return {Object.<string, string>}
-     */
-    function get_query_arguments()
-    {
-        var query = location.search.substr(1).split("&");
-        var parameters = {};
-
-        for(var i = 0; i < query.length; i++)
-        {
-            var param = query[i].split("=");
-            parameters[param[0]] = decodeURIComponent(param.slice(1).join("="));
-        }
-
-        return parameters;
-    }
+    const ON_LOCALHOST = !location.hostname.endsWith("copy.sh");
 
     function set_title(text)
     {
@@ -47,11 +29,11 @@
         }
     }
 
-    var progress_ticks = 0;
+    let progress_ticks = 0;
 
     function show_progress(e)
     {
-        var el = $("loading");
+        const el = $("loading");
         el.style.display = "block";
 
         if(e.file_name.endsWith(".wasm"))
@@ -68,7 +50,7 @@
             return;
         }
 
-        var line = "Downloading images ";
+        let line = "Downloading images ";
 
         if(typeof e.file_index === "number" && e.file_count)
         {
@@ -99,7 +81,7 @@
         return document.getElementById(id);
     }
 
-    // these values are stored in localStorage
+    // These values were previously stored in localStorage
     const elements_to_restore = [
         "memory_size",
         "video_memory_size",
@@ -108,6 +90,14 @@
         "enable_acpi",
         "boot_order",
     ];
+    for(const item of elements_to_restore)
+    {
+        try
+        {
+            window.localStorage.removeItem(item);
+        }
+        catch(e) {}
+    }
 
     function onload()
     {
@@ -117,84 +107,11 @@
             return;
         }
 
-        var settings = {};
-
-        $("start_emulation").onclick = function()
+        $("start_emulation").onclick = function(e)
         {
-            // Save entered options into the local storage
-            for(const id of elements_to_restore)
-            {
-                const element = $(id);
-                if(element)
-                {
-                    if(element.tagName === "SELECT" || element.type !== "checkbox")
-                    {
-                        window.localStorage.setItem(id, element.value);
-                    }
-                    else
-                    {
-                        window.localStorage.setItem(id, element.checked);
-                    }
-                }
-            }
-
-            $("boot_options").style.display = "none";
-            set_profile("custom");
-
-            var images = [];
-            var last_file;
-
-            var bios = $("bios").files[0];
-            if(bios)
-            {
-                last_file = bios;
-                settings.bios = { buffer: bios };
-            }
-
-            var floppy_file = $("floppy_image").files[0];
-            if(floppy_file)
-            {
-                last_file = floppy_file;
-                settings.fda = { buffer: floppy_file };
-            }
-
-            var cd_file = $("cd_image").files[0];
-            if(cd_file)
-            {
-                last_file = cd_file;
-                settings.cdrom = { buffer: cd_file };
-            }
-
-            var hda_file = $("hda_image").files[0];
-            if(hda_file)
-            {
-                last_file = hda_file;
-                settings.hda = { buffer: hda_file };
-            }
-
-            var hdb_file = $("hdb_image") && $("hdb_image").files[0];
-            if(hdb_file)
-            {
-                last_file = hdb_file;
-                settings.hdb = { buffer: hdb_file };
-            }
-
-            if($("multiboot_image"))
-            {
-                var multiboot_file = $("multiboot_image").files[0];
-                if(multiboot_file)
-                {
-                    last_file = multiboot_file;
-                    settings.multiboot = { buffer: multiboot_file };
-                }
-            }
-
-            if(last_file)
-            {
-                set_title(last_file.name);
-            }
-
-            start_emulation(settings);
+            start_emulation(null, null);
+            $("start_emulation").blur();
+            e.preventDefault();
         };
 
         if(DEBUG)
@@ -202,11 +119,17 @@
             debug_onload();
         }
 
-        const query_args = get_query_arguments();
-        const host = query_args["cdn"] || (ON_LOCALHOST ? "images/" : "//i.copy.sh/");
+        if(DEBUG && ON_LOCALHOST)
+        {
+            // don't use online relay in debug mode
+            $("networking_proxy").value = "ws://localhost:8080/";
+        }
+
+        const query_args = new URLSearchParams(location.search);
+        const host = query_args.get("cdn") || (ON_LOCALHOST ? "images/" : "//i.copy.sh/");
 
         // Abandonware OS images are from https://winworldpc.com/library/operating-systems
-        var oses = [
+        const oses = [
             {
                 id: "archlinux",
                 name: "Arch Linux",
@@ -1328,7 +1251,7 @@
         if(DEBUG)
         {
             // see tests/kvm-unit-tests/x86/
-            var tests = [
+            const tests = [
                 "realmode",
                 // All tests below require an APIC
                 "cmpxchg8b",
@@ -1361,7 +1284,7 @@
             }
         }
 
-        var profile = query_args["profile"];
+        const profile = query_args.get("profile");
 
         if(!profile && !DEBUG)
         {
@@ -1376,92 +1299,38 @@
         link.href = "build/xterm.js";
         document.head.appendChild(link);
 
-        if(query_args["disable_jit"])
-        {
-            settings.disable_jit = true;
-        }
-
-        if(query_args["use_bochs_bios"])
-        {
-            settings.use_bochs_bios = true;
-        }
-
-        const m = parseInt(query_args["m"], 10);
-        if(m > 0)
+        for(const os of oses)
         {
-            settings.memory_size = Math.max(16, m) * 1024 * 1024;
-        }
-
-        const vram = parseInt(query_args["vram"], 10);
-        if(vram > 0)
-        {
-            settings.vga_memory_size = vram * 1024 * 1024;
-        }
-
-        settings.networking_proxy = query_args["networking_proxy"];
-        settings.audio = query_args["audio"] !== "0";
-        settings.acpi = query_args["acpi"];
-
-        for(var i = 0; i < oses.length; i++)
-        {
-            var infos = oses[i];
-
-            if(profile === infos.id)
+            if(profile === os.id)
             {
-                start_profile(infos);
+                start_emulation(os, query_args);
                 return;
             }
 
-            var element = $("start_" + infos.id);
+            const element = $("start_" + os.id);
 
             if(element)
             {
-                element.onclick = function(infos, element, e)
+                element.onclick = e =>
                 {
                     e.preventDefault();
-                    set_profile(infos.id);
                     element.blur();
-
-                    start_profile(infos);
-                }.bind(this, infos, element);
+                    start_emulation(os, null);
+                };
             }
         }
 
         if(profile === "custom")
         {
-            if(query_args["hda.url"])
-            {
-                settings.hda = {
-                    size: parseInt(query_args["hda.size"], 10) || undefined,
-                    url: query_args["hda.url"],
-                    async: true,
-                };
-            }
+            // TODO: if one of the file form fields has a value (firefox), start here?
 
-            if(query_args["cdrom.url"])
+            if(query_args.has("hda.url") || query_args.has("cdrom.url") || query_args.has("fda.url"))
             {
-                settings.cdrom = {
-                    size: parseInt(query_args["cdrom.size"], 10) || undefined,
-                    url: query_args["cdrom.url"],
-                    async: true,
-                };
+                start_emulation(null, query_args);
             }
-
-            if(query_args["fda.url"])
-            {
-                settings.fda = {
-                    size: parseInt(query_args["fda.size"], 10) || undefined,
-                    url: query_args["fda.url"],
-                    async: false,
-                };
-            }
-
-            if(settings.fda || settings.cdrom || settings.hda)
+            else
             {
-                $("boot_options").style.display = "none";
-
-                start_emulation(settings, done);
-                return;
+                // TODO: fill input fields with query arg values?
             }
         }
         else if(/^[a-zA-Z0-9\-_]+\/[a-zA-Z0-9\-_]+$/g.test(profile))
@@ -1479,7 +1348,7 @@
                         return o && { url: base + "/" + o["url"], async: o["async"], size: o["size"] };
                     }
 
-                    start_profile({
+                    const profile = {
                         id: p["id"],
                         name: p["name"],
                         memory_size: p["memory_size"],
@@ -1492,183 +1361,70 @@
                         multiboot: handle_image(p["multiboot"]),
                         bzimage: handle_image(p["bzimage"]),
                         initrd: handle_image(p["initrd"]),
-                    });
-                });
+                    };
 
-            return;
+                    start_emulation(profile, query_args);
+                });
         }
+    }
 
-        for(const id of elements_to_restore)
-        {
-            const saved_value = window.localStorage.getItem(id);
+    function debug_onload()
+    {
+        // called on window.onload, in debug mode
 
-            if(saved_value)
-            {
-                const element = $(id);
-                if(element)
-                {
-                    if(element.type === "checkbox")
-                    {
-                        element.checked = saved_value === "true" ? true : false;
-                    }
-                    else
-                    {
-                        element.value = saved_value;
-                    }
-                }
-            }
-        }
+        const log_levels = $("log_levels");
 
-        if(DEBUG && ON_LOCALHOST)
+        if(!log_levels)
         {
-            // don't use online relay in debug mode
-            $("networking_proxy").value = "ws://localhost:8080/";
+            return;
         }
 
-        function start_profile(infos)
+        for(let i = 0; i < LOG_NAMES.length; i++)
         {
-            $("boot_options").style.display = "none";
-            set_title(infos.name);
+            const mask = LOG_NAMES[i][0];
 
-            settings.filesystem = infos.filesystem;
-
-            if(infos.state)
-            {
-                $("reset").style.display = "none";
-                settings.initial_state = infos.state;
-            }
+            if(mask === 1)
+                continue;
 
-            settings.fda = infos.fda;
-            settings.cdrom = infos.cdrom;
-            settings.hda = infos.hda;
-            settings.multiboot = infos.multiboot;
-            settings.bzimage = infos.bzimage;
-            settings.initrd = infos.initrd;
-            settings.cmdline = infos.cmdline;
-            settings.bzimage_initrd_from_filesystem = infos.bzimage_initrd_from_filesystem;
-            settings.mac_address_translation = infos.mac_address_translation;
-            settings.cpuid_level = infos.cpuid_level;
+            const name = LOG_NAMES[i][1].toLowerCase();
+            const input = document.createElement("input");
+            const label = document.createElement("label");
 
-            settings.acpi = (!infos.state && settings.acpi !== undefined) ? settings.acpi : infos.acpi;
-            settings.memory_size = (!infos.state && settings.memory_size) ? settings.memory_size : infos.memory_size;
-            settings.vga_memory_size = (!infos.state && settings.vga_memory_size) ? settings.vga_memory_size : infos.vga_memory_size;
+            input.type = "checkbox";
 
-            settings.disable_vga_display = infos.disable_vga_display;
+            label.htmlFor = input.id = "log_" + name;
 
-            settings.id = infos.id;
-
-            if(infos.boot_order !== undefined)
+            if(LOG_LEVEL & mask)
             {
-                settings.boot_order = infos.boot_order;
+                input.checked = true;
             }
+            input.mask = mask;
 
-            let chunk_size = parseInt(query_args["chunk_size"], 10);
-            if(chunk_size >= 0)
-            {
-                if(chunk_size)
-                {
-                    chunk_size = Math.min(4 * 1024 * 1024, Math.max(512, chunk_size));
-                    chunk_size = 1 << Math.ceil(Math.log2(chunk_size));
-                }
-                else
-                {
-                    chunk_size = undefined;
-                }
-
-                if(settings.hda)
-                {
-                    settings.hda.fixed_chunk_size = chunk_size;
-                }
+            label.append(input, v86util.pads(name, 4) + " ");
+            log_levels.appendChild(label);
 
-                if(settings.cdrom)
-                {
-                    settings.cdrom.fixed_chunk_size = chunk_size;
-                }
-            }
-
-            if(!DEBUG && infos.homepage)
+            if(i === Math.floor(LOG_NAMES.length / 2))
             {
-                $("description").style.display = "block";
-                const link = document.createElement("a");
-                link.href = infos.homepage;
-                link.textContent = infos.name;
-                link.target = "_blank";
-                $("description").appendChild(document.createTextNode("Running "));
-                $("description").appendChild(link);
+                log_levels.append("\n");
             }
-
-            start_emulation(settings, done);
         }
 
-        function done(emulator)
+        log_levels.onchange = function(e)
         {
-            if(query_args["c"])
-            {
-                setTimeout(function()
-                {
-                    //emulator.serial0_send(query_args["c"] + "\n");
-                    emulator.keyboard_send_text(query_args["c"] + "\n");
-                }, 25);
-            }
-        }
-    }
-
-    function debug_onload()
-    {
-        // called on window.onload, in debug mode
+            const target = e.target;
+            const mask = target.mask;
 
-        var log_levels = $("log_levels");
-
-        if(log_levels)
-        {
-            for(var i = 0; i < LOG_NAMES.length; i++)
+            if(target.checked)
             {
-                var mask = LOG_NAMES[i][0];
-
-                if(mask === 1)
-                    continue;
-
-                var name = LOG_NAMES[i][1].toLowerCase(),
-                    input = document.createElement("input"),
-                    label = document.createElement("label");
-
-                input.type = "checkbox";
-
-                label.htmlFor = input.id = "log_" + name;
-
-                if(LOG_LEVEL & mask)
-                {
-                    input.checked = true;
-                }
-                input.mask = mask;
-
-                label.appendChild(input);
-                label.appendChild(document.createTextNode(v86util.pads(name, 4) + " "));
-                log_levels.appendChild(label);
-
-                if(i === Math.floor(LOG_NAMES.length / 2))
-                {
-                    log_levels.appendChild(document.createTextNode("\n"));
-                }
+                LOG_LEVEL |= mask;
             }
-
-            log_levels.onchange = function(e)
+            else
             {
-                var target = e.target,
-                    mask = target.mask;
-
-                if(target.checked)
-                {
-                    LOG_LEVEL |= mask;
-                }
-                else
-                {
-                    LOG_LEVEL &= ~mask;
-                }
+                LOG_LEVEL &= ~mask;
+            }
 
-                target.blur();
-            };
-        }
+            target.blur();
+        };
     }
 
     window.addEventListener("load", onload, false);
@@ -1689,145 +1445,269 @@
         onload();
     }
 
-    /** @param {?=} done */
-    function start_emulation(settings, done)
+    // we can get here in various ways:
+    // - the user clicked on the "start emulation"
+    // - the user clicked on a profile
+    // - the ?profile= query parameter specified a valid profile
+    // - the ?profile= query parameter was set to "custom" and at least one disk image was given
+    function start_emulation(profile, query_args)
     {
-        /** @const */
-        var MB = 1024 * 1024;
-
-        var memory_size = settings.memory_size;
+        $("boot_options").style.display = "none";
 
-        if(!memory_size)
+        if(!query_args)
         {
-            memory_size = parseInt($("memory_size").value, 10) * MB;
-
-            if(!memory_size)
-            {
-                alert("Invalid memory size - reset to 128MB");
-                memory_size = 128 * MB;
-            }
+            set_profile(profile?.id || "custom");
         }
 
-        var vga_memory_size = settings.vga_memory_size;
+        const settings = {};
 
-        if(!vga_memory_size)
+        if(profile)
         {
-            vga_memory_size = parseInt($("video_memory_size").value, 10) * MB;
+            if(profile.state)
+            {
+                $("reset").style.display = "none";
+            }
 
-            if(!vga_memory_size)
+            set_title(profile.name);
+
+            settings.initial_state = profile.state;
+            settings.filesystem = profile.filesystem;
+            settings.fda = profile.fda;
+            settings.cdrom = profile.cdrom;
+            settings.hda = profile.hda;
+            settings.multiboot = profile.multiboot;
+            settings.bzimage = profile.bzimage;
+            settings.initrd = profile.initrd;
+            settings.cmdline = profile.cmdline;
+            settings.bzimage_initrd_from_filesystem = profile.bzimage_initrd_from_filesystem;
+            settings.mac_address_translation = profile.mac_address_translation;
+            settings.cpuid_level = profile.cpuid_level;
+            settings.acpi = profile.acpi;
+            settings.memory_size = profile.memory_size;
+            settings.vga_memory_size = profile.vga_memory_size;
+            settings.boot_order = profile.boot_order;
+
+            if(!DEBUG && profile.homepage)
             {
-                alert("Invalid video memory size - reset to 8MB");
-                vga_memory_size = 8 * MB;
+                $("description").style.display = "block";
+                const link = document.createElement("a");
+                link.href = profile.homepage;
+                link.textContent = profile.name;
+                link.target = "_blank";
+                $("description").append(document.createTextNode("Running "), link);
             }
         }
 
-        if(!settings.bios)
+        if(query_args)
         {
-            var bios = $("bios").files[0];
-            if(bios)
+            // ignore certain settings when using a state image
+            if(!settings.initial_state)
             {
-                settings.bios = { buffer: bios };
+                let chunk_size = parseInt(query_args.get("chunk_size"), 10);
+                if(chunk_size >= 0)
+                {
+                    chunk_size = Math.min(4 * 1024 * 1024, Math.max(512, chunk_size));
+                    chunk_size = v86util.round_up_to_next_power_of_2(chunk_size);
+                }
+                else
+                {
+                    chunk_size = 256 * 1024;
+                }
+
+                if(query_args.has("hda.url"))
+                {
+                    settings.hda = {
+                        size: parseInt(query_args.get("hda.size"), 10) || undefined,
+                        // TODO: synchronous if small?
+                        url: query_args.get("hda.url"),
+                        fixed_chunk_size: chunk_size,
+                        async: true,
+                    };
+                }
+
+                if(query_args.has("cdrom.url"))
+                {
+                    settings.cdrom = {
+                        size: parseInt(query_args.get("cdrom.size"), 10) || undefined,
+                        url: query_args.get("cdrom.url"),
+                        fixed_chunk_size: chunk_size,
+                        async: true,
+                    };
+                }
+
+                if(query_args.has("fda.url"))
+                {
+                    settings.fda = {
+                        size: parseInt(query_args.get("fda.size"), 10) || undefined,
+                        url: query_args.get("fda.url"),
+                        async: false,
+                    };
+                }
+
+                const m = parseInt(query_args.get("m"), 10);
+                if(m > 0)
+                {
+                    settings.memory_size = Math.max(16, m) * 1024 * 1024;
+                }
+
+                const vram = parseInt(query_args.get("vram"), 10);
+                if(vram > 0)
+                {
+                    settings.vga_memory_size = vram * 1024 * 1024;
+                }
+
+                settings.acpi = query_args.has("acpi") ? !!query_args.get("acpi") : undefined;
+                settings.use_bochs_bios = !!query_args.get("use_bochs_bios");
             }
+
+            settings.disable_jit = !!query_args.get("disable_jit");
+            settings.networking_proxy = query_args.get("networking_proxy");
+            settings.audio = query_args.get("audio") && query_args.get("audio") !== "0";
         }
 
-        if(!settings.fda)
+        if(!settings.networking_proxy)
         {
-            var floppy_file = $("floppy_image").files[0];
-            if(floppy_file)
-            {
-                settings.fda = { buffer: floppy_file };
-            }
+            settings.networking_proxy = $("networking_proxy").value;
         }
+        settings.disable_audio = $("disable_audio").checked || !settings.audio;
 
-        if(!settings.bzimage)
+        // some settings cannot be overridden when a state image is used
+        if(!settings.initial_state)
         {
-            var bzimage = $("bzimage").files[0];
+            const bios = $("bios").files[0];
+            if(bios && !settings.initial_state)
+            {
+                settings.bios = { buffer: bios };
+            }
+            const fda = $("floppy_image").files[0];
+            if(fda)
+            {
+                settings.fda = { buffer: fda };
+            }
+            const cdrom = $("cdrom_image").files[0];
+            if(cdrom)
+            {
+                settings.cdrom = { buffer: cdrom };
+            }
+            const hda = $("hda_image").files[0];
+            if(hda)
+            {
+                settings.hda = { buffer: hda };
+            }
+            const hdb = $("hdb_image")?.files[0];
+            if(hdb)
+            {
+                settings.hdb = { buffer: hdb };
+            }
+            const multiboot = $("multiboot_image")?.files[0];
+            if(multiboot)
+            {
+                settings.multiboot = { buffer: multiboot };
+            }
+            const bzimage = $("bzimage").files[0];
             if(bzimage)
             {
                 settings.bzimage = { buffer: bzimage };
             }
-        }
-
-        if(!settings.initrd)
-        {
-            var initrd = $("initrd").files[0];
+            const initrd = $("initrd").files[0];
             if(initrd)
             {
                 settings.initrd = { buffer: initrd };
             }
-        }
 
-        const networking_proxy = settings.networking_proxy === undefined ? $("networking_proxy").value : settings.networking_proxy;
-        const disable_audio = $("disable_audio").checked || !settings.audio;
-        const enable_acpi = !settings.initial_state && settings.acpi === undefined ? $("enable_acpi").checked : settings.acpi;
+            const title = multiboot?.name || hda?.name || cdrom?.name || hdb?.name || fda?.name || bios?.name;
+            if(title)
+            {
+                set_title(title);
+            }
 
-        /** @const */
-        var BIOSPATH = "bios/";
+            const MB = 1024 * 1024;
 
-        if(settings.use_bochs_bios)
-        {
-            var biosfile = "bochs-bios.bin";
-            var vgabiosfile = "bochs-vgabios.bin";
-        }
-        else
-        {
-            var biosfile = DEBUG ? "seabios-debug.bin" : "seabios.bin";
-            var vgabiosfile = DEBUG ? "vgabios-debug.bin" : "vgabios.bin";
-        }
+            if(!settings.memory_size)
+            {
+                let memory_size = parseInt($("memory_size").value, 10) * MB;
+                if(!memory_size)
+                {
+                    alert("Invalid memory size - reset to 128MB");
+                    memory_size = 128 * MB;
+                }
+                settings.memory_size = memory_size;
+            }
+            if(!settings.vga_memory_size)
+            {
+                let vga_memory_size = parseInt($("video_memory_size").value, 10) * MB;
+                if(!vga_memory_size)
+                {
+                    alert("Invalid video memory size - reset to 8MB");
+                    vga_memory_size = 8 * MB;
+                }
+                settings.vga_memory_size = vga_memory_size;
+            }
 
-        var bios;
-        var vga_bios;
+            if(!settings.boot_order)
+            {
+                settings.boot_order = parseInt($("boot_order").value, 16) || 0;
+            }
 
-        // a bios is only needed if the machine is booted
-        if(!settings.initial_state)
-        {
-            bios = {
-                url: BIOSPATH + biosfile,
-            };
-            vga_bios = {
-                url: BIOSPATH + vgabiosfile,
-            };
-        }
+            if(settings.acpi === undefined)
+            {
+                settings.acpi = $("enable_acpi").checked;
+            }
 
-        var emulator = new V86({
-            memory_size: memory_size,
-            vga_memory_size: vga_memory_size,
+            if(!settings.bios)
+            {
+                const BIOSPATH = "bios/";
 
-            screen_container: settings.disable_vga_display ? null : $("screen_container"),
+                if(settings.use_bochs_bios)
+                {
+                    var biosfile = "bochs-bios.bin";
+                    var vgabiosfile = "bochs-vgabios.bin";
+                }
+                else
+                {
+                    var biosfile = DEBUG ? "seabios-debug.bin" : "seabios.bin";
+                    var vgabiosfile = DEBUG ? "vgabios-debug.bin" : "vgabios.bin";
+                }
 
-            boot_order: settings.boot_order || parseInt($("boot_order").value, 16) || 0,
+                settings.bios = { url: BIOSPATH + biosfile };
+                settings.vga_bios = { url: BIOSPATH + vgabiosfile };
+            }
+        }
 
+        const emulator = new V86({
+            screen_container: $("screen_container"),
             net_device: {
                 type: "ne2k",
-                relay_url: networking_proxy,
+                relay_url: settings.networking_proxy,
             },
+            autostart: true,
 
-            bios: settings.bios || bios,
-            vga_bios: settings.bios ? null : vga_bios,
+            memory_size: settings.memory_size,
+            vga_memory_size: settings.vga_memory_size,
+            boot_order: settings.boot_order,
 
+            bios: settings.bios,
+            vga_bios: settings.vga_bios,
             fda: settings.fda,
             hda: settings.hda,
             hdb: settings.hdb,
             cdrom: settings.cdrom,
-
             multiboot: settings.multiboot,
             bzimage: settings.bzimage,
             initrd: settings.initrd,
+
             cmdline: settings.cmdline,
             bzimage_initrd_from_filesystem: settings.bzimage_initrd_from_filesystem,
-
-            acpi: enable_acpi,
+            acpi: settings.acpi,
             disable_jit: settings.disable_jit,
             initial_state: settings.initial_state,
             filesystem: settings.filesystem || {},
-            disable_speaker: disable_audio,
+            disable_speaker: settings.disable_audio,
             mac_address_translation: settings.mac_address_translation,
             cpuid_level: settings.cpuid_level,
-
-            autostart: true,
         });
 
-        if(DEBUG) window["emulator"] = emulator;
+        if(DEBUG) window.emulator = emulator;
 
         emulator.add_listener("emulator-ready", function()
         {
@@ -1840,7 +1720,7 @@
             {
                 const CLEAR_STATS = false;
 
-                var panel = document.createElement("pre");
+                const panel = document.createElement("pre");
                 document.body.appendChild(panel);
 
                 setInterval(function()
@@ -1857,7 +1737,7 @@
                     }, CLEAR_STATS ? 5000 : 1000);
             }
 
-            if(settings.id === "dsl" || settings.id === "helenos" || settings.id === "android" || settings.id === "android4")
+            if(["dsl", "helenos", "android", "android4"].includes(profile?.id))
             {
                 setTimeout(() => {
                     // hack: Start automatically
@@ -1867,7 +1747,21 @@
 
             init_ui(settings, emulator);
 
-            done && done(emulator);
+            if(query_args?.has("c"))
+            {
+                setTimeout(function()
+                {
+                    emulator.keyboard_send_text(query_args.get("c") + "\n");
+                }, 25);
+            }
+
+            if(query_args?.has("s"))
+            {
+                setTimeout(function()
+                {
+                    emulator.serial0_send(query_args.get("s") + "\n");
+                }, 25);
+            }
         });
 
         emulator.add_listener("download-progress", function(e)
@@ -1877,10 +1771,9 @@
 
         emulator.add_listener("download-error", function(e)
         {
-            var el = $("loading");
+            const el = $("loading");
             el.style.display = "block";
-            el.textContent = "Loading " + e.file_name + " failed. Check your connection " +
-                             "and reload the page to try again.";
+            el.textContent = `Loading ${e.file_name} failed. Check your connection and reload the page to try again.`;
         });
     }
 
@@ -1890,11 +1783,10 @@
      */
     function init_ui(settings, emulator)
     {
-        $("boot_options").style.display = "none";
         $("loading").style.display = "none";
         $("runtime_options").style.display = "block";
         $("runtime_infos").style.display = "block";
-        if(!settings.disable_vga_display) $("screen_container").style.display = "block";
+        $("screen_container").style.display = "block";
 
         if(settings.filesystem)
         {
@@ -1952,7 +1844,6 @@
             $("toggle_mouse").blur();
         };
 
-
         var last_tick = 0;
         var running_time = 0;
         var last_instr_counter = 0;
@@ -2547,7 +2438,6 @@
         }, 1000);
 
         // helps debugging
-        window.emulator = emulator;
         window.cpu = cpu;
         window.dump_file = dump_file;
     }

From ca7fe7542c58ba00ea4cf8edb64ed63161b07f42 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 23:02:13 -0600
Subject: [PATCH 15/23] refactor query parameter handling

- create query parameters for memory size, mute, acpi, boot order and networking proxy
- allow overwriting memory size, boot and acpi order for profiles
---
 debug.html          |  8 ++---
 index.html          |  8 ++---
 src/browser/main.js | 80 +++++++++++++++++++++++++++------------------
 3 files changed, 56 insertions(+), 40 deletions(-)

diff --git a/debug.html b/debug.html
index 6fd6fa46fa..d79f84670b 100644
--- a/debug.html
+++ b/debug.html
@@ -179,9 +179,9 @@ <h4>Debugger</h4>
             </tr>
 
             <tr>
-                <td><label for="video_memory_size">Video Memory size</label></td>
+                <td><label for="vga_memory_size">Video Memory size</label></td>
                 <td>
-                    <input id="video_memory_size" type="number" value="8" min="1" max="128" step="1"> MB<br>
+                    <input id="vga_memory_size" type="number" value="8" min="1" max="128" step="1"> MB<br>
                 </td>
             </tr>
 
@@ -204,9 +204,9 @@ <h4>Debugger</h4>
             </tr>
 
             <tr>
-                <td><label for="enable_acpi">Enable ACPI (experimental)</label></td>
+                <td><label for="acpi">Enable ACPI (experimental)</label></td>
                 <td>
-                    <input id="enable_acpi" type="checkbox"><br>
+                    <input id="acpi" type="checkbox"><br>
                 </td>
             </tr>
 
diff --git a/index.html b/index.html
index 05da552de8..3697eeaabd 100644
--- a/index.html
+++ b/index.html
@@ -119,9 +119,9 @@ <h4>Setup</h4>
             </tr>
 
             <tr>
-                <td><label for="video_memory_size">Video Memory size</label></td>
+                <td><label for="vga_memory_size">Video Memory size</label></td>
                 <td>
-                    <input id="video_memory_size" type="number" value="8" min="1" max="128" step="1"> MB<br>
+                    <input id="vga_memory_size" type="number" value="8" min="1" max="128" step="1"> MB<br>
                 </td>
             </tr>
 
@@ -144,9 +144,9 @@ <h4>Setup</h4>
             </tr>
 
             <tr>
-                <td><label for="enable_acpi">Enable ACPI (experimental)</label></td>
+                <td><label for="acpi">Enable ACPI (experimental)</label></td>
                 <td>
-                    <input id="enable_acpi" type="checkbox"><br>
+                    <input id="acpi" type="checkbox"><br>
                 </td>
             </tr>
 
diff --git a/src/browser/main.js b/src/browser/main.js
index 49ec5a33eb..6553baa9e3 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -4,6 +4,11 @@
 {
     const ON_LOCALHOST = !location.hostname.endsWith("copy.sh");
 
+    const DEFAULT_NETWORKING_PROXIES = ["wss://relay.widgetry.org/", "ws://localhost:8080/"];
+    const DEFAULT_MEMORY_SIZE = 128;
+    const DEFAULT_VGA_MEMORY_SIZE = 8;
+    const DEFAULT_BOOT_ORDER = 0;
+
     function set_title(text)
     {
         document.title = text + " - Virtual x86" +  (DEBUG ? " - debug" : "");
@@ -11,6 +16,11 @@
         description && (description.content = "Running " + text);
     }
 
+    function bool_arg(x)
+    {
+        return !!x && x !== "0";
+    }
+
     function format_timestamp(time)
     {
         if(time < 60)
@@ -1330,7 +1340,12 @@
             }
             else
             {
-                // TODO: fill input fields with query arg values?
+                if(query_args.has("m")) $("memory_size").value = query_args.get("m");
+                if(query_args.has("vram")) $("vga_memory_size").value = query_args.get("vram");
+                if(query_args.has("networking_proxy")) $("networking_proxy").value = query_args.get("networking_proxy");
+                if(query_args.has("mute")) $("disable_audio").checked = bool_arg(query_args.get("mute"));
+                if(query_args.has("acpi")) $("acpi").checked = bool_arg(query_args.get("acpi"));
+                if(query_args.has("boot_order")) $("boot_order").value = query_args.get("boot_order");
             }
         }
         else if(/^[a-zA-Z0-9\-_]+\/[a-zA-Z0-9\-_]+$/g.test(profile))
@@ -1454,10 +1469,7 @@
     {
         $("boot_options").style.display = "none";
 
-        if(!query_args)
-        {
-            set_profile(profile?.id || "custom");
-        }
+        const new_query_args = new URLSearchParams({ "profile": profile?.id || "custom" });
 
         const settings = {};
 
@@ -1556,26 +1568,28 @@
                     settings.vga_memory_size = vram * 1024 * 1024;
                 }
 
-                settings.acpi = query_args.has("acpi") ? !!query_args.get("acpi") : undefined;
-                settings.use_bochs_bios = !!query_args.get("use_bochs_bios");
+                settings.acpi = query_args.has("acpi") ? bool_arg(query_args.get("acpi")) : undefined;
+                settings.use_bochs_bios = query_args.get("bios") === "bochs";
             }
 
-            settings.disable_jit = !!query_args.get("disable_jit");
             settings.networking_proxy = query_args.get("networking_proxy");
-            settings.audio = query_args.get("audio") && query_args.get("audio") !== "0";
+            settings.disable_jit = bool_arg(query_args.get("disable_jit"));
+            settings.disable_audio = bool_arg(query_args.get("mute"));
         }
 
         if(!settings.networking_proxy)
         {
             settings.networking_proxy = $("networking_proxy").value;
+            if(!DEFAULT_NETWORKING_PROXIES.includes(settings.networking_proxy)) new_query_args.append("networking_proxy", settings.networking_proxy);
         }
-        settings.disable_audio = $("disable_audio").checked || !settings.audio;
+        settings.disable_audio = $("disable_audio").checked || settings.disable_audio;
+        if(settings.disable_audio) new_query_args.append("mute", "1");
 
         // some settings cannot be overridden when a state image is used
         if(!settings.initial_state)
         {
             const bios = $("bios").files[0];
-            if(bios && !settings.initial_state)
+            if(bios)
             {
                 settings.bios = { buffer: bios };
             }
@@ -1623,35 +1637,31 @@
 
             const MB = 1024 * 1024;
 
-            if(!settings.memory_size)
+            const memory_size = parseInt($("memory_size").value, 10) || DEFAULT_MEMORY_SIZE;
+            if(!settings.memory_size || memory_size !== DEFAULT_MEMORY_SIZE)
             {
-                let memory_size = parseInt($("memory_size").value, 10) * MB;
-                if(!memory_size)
-                {
-                    alert("Invalid memory size - reset to 128MB");
-                    memory_size = 128 * MB;
-                }
-                settings.memory_size = memory_size;
+                settings.memory_size = memory_size * MB;
             }
-            if(!settings.vga_memory_size)
+            if(memory_size !== DEFAULT_MEMORY_SIZE) new_query_args.append("m", String(memory_size));
+
+            const vga_memory_size = parseInt($("vga_memory_size").value, 10) || DEFAULT_VGA_MEMORY_SIZE;
+            if(!settings.vga_memory_size || vga_memory_size !== DEFAULT_VGA_MEMORY_SIZE)
             {
-                let vga_memory_size = parseInt($("video_memory_size").value, 10) * MB;
-                if(!vga_memory_size)
-                {
-                    alert("Invalid video memory size - reset to 8MB");
-                    vga_memory_size = 8 * MB;
-                }
-                settings.vga_memory_size = vga_memory_size;
+                settings.vga_memory_size = vga_memory_size * MB;
             }
+            if(vga_memory_size !== DEFAULT_VGA_MEMORY_SIZE) new_query_args.append("vram", String(vga_memory_size));
 
-            if(!settings.boot_order)
+            const boot_order = parseInt($("boot_order").value, 16) || DEFAULT_BOOT_ORDER;
+            if(!settings.boot_order || boot_order !== DEFAULT_BOOT_ORDER)
             {
-                settings.boot_order = parseInt($("boot_order").value, 16) || 0;
+                settings.boot_order = boot_order;
             }
+            if(settings.boot_order !== DEFAULT_BOOT_ORDER) new_query_args.append("boot_order", String(settings.boot_order));
 
             if(settings.acpi === undefined)
             {
-                settings.acpi = $("enable_acpi").checked;
+                settings.acpi = $("acpi").checked;
+                if(settings.acpi) new_query_args.append("acpi", "1");
             }
 
             if(!settings.bios)
@@ -1674,6 +1684,11 @@
             }
         }
 
+        if(!query_args)
+        {
+            push_state(new_query_args);
+        }
+
         const emulator = new V86({
             screen_container: $("screen_container"),
             net_device: {
@@ -2447,11 +2462,12 @@
         location.reload();
     }
 
-    function set_profile(prof)
+    function push_state(params)
     {
         if(window.history.pushState)
         {
-            window.history.pushState({ profile: prof }, "", "?profile=" + prof);
+            const search = "?" + params.toString();
+            window.history.pushState({ search }, "", search);
         }
     }
 

From a7563e0d357f5924ce5ffe4601fe50e144424de4 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Fri, 20 Sep 2024 23:08:03 -0600
Subject: [PATCH 16/23] s/networking_proxy/relay_url

---
 debug.html          |  4 ++--
 index.html          |  4 ++--
 src/browser/main.js | 14 +++++++-------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/debug.html b/debug.html
index d79f84670b..a4e2d20c1a 100644
--- a/debug.html
+++ b/debug.html
@@ -186,9 +186,9 @@ <h4>Debugger</h4>
             </tr>
 
             <tr>
-                <td><label for="networking_proxy">Networking proxy (leave blank to disable)</label></td>
+                <td><label for="relay_url">Networking proxy (leave blank to disable)</label></td>
                 <td>
-                    <input id="networking_proxy" type="text" value="wss://relay.widgetry.org/">
+                    <input id="relay_url" type="text" value="wss://relay.widgetry.org/">
                 </td>
             </tr>
 
diff --git a/index.html b/index.html
index 3697eeaabd..ee08215592 100644
--- a/index.html
+++ b/index.html
@@ -126,9 +126,9 @@ <h4>Setup</h4>
             </tr>
 
             <tr>
-                <td><label for="networking_proxy">Networking proxy (leave blank to disable)</label></td>
+                <td><label for="relay_url">Networking proxy (leave blank to disable)</label></td>
                 <td>
-                    <input id="networking_proxy" type="text" value="wss://relay.widgetry.org/">
+                    <input id="relay_url" type="text" value="wss://relay.widgetry.org/">
                 </td>
             </tr>
 
diff --git a/src/browser/main.js b/src/browser/main.js
index 6553baa9e3..f952e7e838 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -132,7 +132,7 @@
         if(DEBUG && ON_LOCALHOST)
         {
             // don't use online relay in debug mode
-            $("networking_proxy").value = "ws://localhost:8080/";
+            $("relay_url").value = "ws://localhost:8080/";
         }
 
         const query_args = new URLSearchParams(location.search);
@@ -1342,7 +1342,7 @@
             {
                 if(query_args.has("m")) $("memory_size").value = query_args.get("m");
                 if(query_args.has("vram")) $("vga_memory_size").value = query_args.get("vram");
-                if(query_args.has("networking_proxy")) $("networking_proxy").value = query_args.get("networking_proxy");
+                if(query_args.has("relay_url")) $("relay_url").value = query_args.get("relay_url");
                 if(query_args.has("mute")) $("disable_audio").checked = bool_arg(query_args.get("mute"));
                 if(query_args.has("acpi")) $("acpi").checked = bool_arg(query_args.get("acpi"));
                 if(query_args.has("boot_order")) $("boot_order").value = query_args.get("boot_order");
@@ -1572,15 +1572,15 @@
                 settings.use_bochs_bios = query_args.get("bios") === "bochs";
             }
 
-            settings.networking_proxy = query_args.get("networking_proxy");
+            settings.relay_url = query_args.get("relay_url");
             settings.disable_jit = bool_arg(query_args.get("disable_jit"));
             settings.disable_audio = bool_arg(query_args.get("mute"));
         }
 
-        if(!settings.networking_proxy)
+        if(!settings.relay_url)
         {
-            settings.networking_proxy = $("networking_proxy").value;
-            if(!DEFAULT_NETWORKING_PROXIES.includes(settings.networking_proxy)) new_query_args.append("networking_proxy", settings.networking_proxy);
+            settings.relay_url = $("relay_url").value;
+            if(!DEFAULT_NETWORKING_PROXIES.includes(settings.relay_url)) new_query_args.append("relay_url", settings.relay_url);
         }
         settings.disable_audio = $("disable_audio").checked || settings.disable_audio;
         if(settings.disable_audio) new_query_args.append("mute", "1");
@@ -1693,7 +1693,7 @@
             screen_container: $("screen_container"),
             net_device: {
                 type: "ne2k",
-                relay_url: settings.networking_proxy,
+                relay_url: settings.relay_url,
             },
             autostart: true,
 

From ffb0768edbce76647a051b6ba5f603512e7c2b51 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sat, 21 Sep 2024 11:32:03 -0600
Subject: [PATCH 17/23] late c2rust cleanup (modrm)

---
 src/rust/cpu/modrm.rs | 191 ++++++++++++++----------------------------
 1 file changed, 61 insertions(+), 130 deletions(-)

diff --git a/src/rust/cpu/modrm.rs b/src/rust/cpu/modrm.rs
index f8add01e64..af085a0747 100644
--- a/src/rust/cpu/modrm.rs
+++ b/src/rust/cpu/modrm.rs
@@ -2,76 +2,36 @@ use cpu::cpu::*;
 use paging::OrPageFault;
 
 pub unsafe fn resolve_modrm16(modrm_byte: i32) -> OrPageFault<i32> {
-    Ok(match modrm_byte {
-        0 | 8 | 16 | 24 | 32 | 40 | 48 | 56 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) & 0xFFFF)?
-        },
-        64 | 72 | 80 | 88 | 96 | 104 | 112 | 120 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) + read_imm8s()? & 0xFFFF)?
-        },
-        128 | 136 | 144 | 152 | 160 | 168 | 176 | 184 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) + read_imm16()? & 0xFFFF)?
-        },
-        1 | 9 | 17 | 25 | 33 | 41 | 49 | 57 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) & 0xFFFF)?
-        },
-        65 | 73 | 81 | 89 | 97 | 105 | 113 | 121 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) + read_imm8s()? & 0xFFFF)?
-        },
-        129 | 137 | 145 | 153 | 161 | 169 | 177 | 185 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) + read_imm16()? & 0xFFFF)?
-        },
-        2 | 10 | 18 | 26 | 34 | 42 | 50 | 58 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) & 0xFFFF)?
-        },
-        66 | 74 | 82 | 90 | 98 | 106 | 114 | 122 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) + read_imm8s()? & 0xFFFF)?
-        },
-        130 | 138 | 146 | 154 | 162 | 170 | 178 | 186 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) + read_imm16()? & 0xFFFF)?
-        },
-        3 | 11 | 19 | 27 | 35 | 43 | 51 | 59 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) & 0xFFFF)?
-        },
-        67 | 75 | 83 | 91 | 99 | 107 | 115 | 123 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) + read_imm8s()? & 0xFFFF)?
-        },
-        131 | 139 | 147 | 155 | 163 | 171 | 179 | 187 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) + read_imm16()? & 0xFFFF)?
-        },
-        4 | 12 | 20 | 28 | 36 | 44 | 52 | 60 => get_seg_prefix_ds(read_reg16(SI) & 0xFFFF)?,
-        68 | 76 | 84 | 92 | 100 | 108 | 116 | 124 => {
-            get_seg_prefix_ds(read_reg16(SI) + read_imm8s()? & 0xFFFF)?
-        },
-        132 | 140 | 148 | 156 | 164 | 172 | 180 | 188 => {
-            get_seg_prefix_ds(read_reg16(SI) + read_imm16()? & 0xFFFF)?
-        },
-        5 | 13 | 21 | 29 | 37 | 45 | 53 | 61 => get_seg_prefix_ds(read_reg16(DI) & 0xFFFF)?,
-        69 | 77 | 85 | 93 | 101 | 109 | 117 | 125 => {
-            get_seg_prefix_ds(read_reg16(DI) + read_imm8s()? & 0xFFFF)?
-        },
-        133 | 141 | 149 | 157 | 165 | 173 | 181 | 189 => {
-            get_seg_prefix_ds(read_reg16(DI) + read_imm16()? & 0xFFFF)?
-        },
-        6 | 14 | 22 | 30 | 38 | 46 | 54 | 62 => get_seg_prefix_ds(read_imm16()?)?,
-        70 | 78 | 86 | 94 | 102 | 110 | 118 | 126 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_imm8s()? & 0xFFFF)?
-        },
-        134 | 142 | 150 | 158 | 166 | 174 | 182 | 190 => {
-            get_seg_prefix_ss(read_reg16(BP) + read_imm16()? & 0xFFFF)?
-        },
-        7 | 15 | 23 | 31 | 39 | 47 | 55 | 63 => get_seg_prefix_ds(read_reg16(BX) & 0xFFFF)?,
-        71 | 79 | 87 | 95 | 103 | 111 | 119 | 127 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_imm8s()? & 0xFFFF)?
-        },
-        135 | 143 | 151 | 159 | 167 | 175 | 183 | 191 => {
-            get_seg_prefix_ds(read_reg16(BX) + read_imm16()? & 0xFFFF)?
-        },
+    match modrm_byte & !0o070 {
+        0o000 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) & 0xFFFF),
+        0o100 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) + read_imm8s()? & 0xFFFF),
+        0o200 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(SI) + read_imm16()? & 0xFFFF),
+        0o001 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) & 0xFFFF),
+        0o101 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) + read_imm8s()? & 0xFFFF),
+        0o201 => get_seg_prefix_ds(read_reg16(BX) + read_reg16(DI) + read_imm16()? & 0xFFFF),
+        0o002 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) & 0xFFFF),
+        0o102 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) + read_imm8s()? & 0xFFFF),
+        0o202 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(SI) + read_imm16()? & 0xFFFF),
+        0o003 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) & 0xFFFF),
+        0o103 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) + read_imm8s()? & 0xFFFF),
+        0o203 => get_seg_prefix_ss(read_reg16(BP) + read_reg16(DI) + read_imm16()? & 0xFFFF),
+        0o004 => get_seg_prefix_ds(read_reg16(SI) & 0xFFFF),
+        0o104 => get_seg_prefix_ds(read_reg16(SI) + read_imm8s()? & 0xFFFF),
+        0o204 => get_seg_prefix_ds(read_reg16(SI) + read_imm16()? & 0xFFFF),
+        0o005 => get_seg_prefix_ds(read_reg16(DI) & 0xFFFF),
+        0o105 => get_seg_prefix_ds(read_reg16(DI) + read_imm8s()? & 0xFFFF),
+        0o205 => get_seg_prefix_ds(read_reg16(DI) + read_imm16()? & 0xFFFF),
+        0o006 => get_seg_prefix_ds(read_imm16()?),
+        0o106 => get_seg_prefix_ss(read_reg16(BP) + read_imm8s()? & 0xFFFF),
+        0o206 => get_seg_prefix_ss(read_reg16(BP) + read_imm16()? & 0xFFFF),
+        0o007 => get_seg_prefix_ds(read_reg16(BX) & 0xFFFF),
+        0o107 => get_seg_prefix_ds(read_reg16(BX) + read_imm8s()? & 0xFFFF),
+        0o207 => get_seg_prefix_ds(read_reg16(BX) + read_imm16()? & 0xFFFF),
         _ => {
             dbg_assert!(false);
             0
         },
-    })
+    }
 }
 
 pub unsafe fn resolve_modrm32_(modrm_byte: i32) -> OrPageFault<i32> {
@@ -105,17 +65,16 @@ pub unsafe fn resolve_modrm32_(modrm_byte: i32) -> OrPageFault<i32> {
     })
 }
 unsafe fn resolve_sib(with_imm: bool) -> OrPageFault<i32> {
-    let s;
-    let sib_byte = read_imm8()? as u8;
-    let r = (sib_byte as i32 & 7) as u8;
-    let m = (sib_byte as i32 >> 3 & 7) as u8;
+    let sib_byte = read_imm8()?;
+    let r = sib_byte & 7;
+    let m = sib_byte >> 3 & 7;
     let base;
     let seg;
-    if r as i32 == 4 {
+    if r == 4 {
         base = read_reg32(ESP);
         seg = SS
     }
-    else if r as i32 == 5 {
+    else if r == 5 {
         if with_imm {
             base = read_reg32(EBP);
             seg = SS
@@ -126,77 +85,49 @@ unsafe fn resolve_sib(with_imm: bool) -> OrPageFault<i32> {
         }
     }
     else {
-        base = read_reg32(r as i32);
+        base = read_reg32(r);
         seg = DS
     }
     let offset;
-    if m as i32 == 4 {
+    if m == 4 {
         offset = 0
     }
     else {
-        s = (sib_byte as i32 >> 6 & 3) as u8;
-        offset = read_reg32(m as i32) << s as i32
+        let s = sib_byte >> 6 & 3;
+        offset = read_reg32(m) << s
     }
     Ok(get_seg_prefix(seg)? + base + offset)
 }
 
 pub unsafe fn resolve_modrm32(modrm_byte: i32) -> OrPageFault<i32> {
-    Ok(match modrm_byte {
-        0 | 8 | 16 | 24 | 32 | 40 | 48 | 56 => get_seg_prefix_ds(read_reg32(EAX))?,
-        64 | 72 | 80 | 88 | 96 | 104 | 112 | 120 => {
-            get_seg_prefix_ds(read_reg32(EAX) + read_imm8s()?)?
-        },
-        128 | 136 | 144 | 152 | 160 | 168 | 176 | 184 => {
-            get_seg_prefix_ds(read_reg32(EAX) + read_imm32s()?)?
-        },
-        1 | 9 | 17 | 25 | 33 | 41 | 49 | 57 => get_seg_prefix_ds(read_reg32(ECX))?,
-        65 | 73 | 81 | 89 | 97 | 105 | 113 | 121 => {
-            get_seg_prefix_ds(read_reg32(ECX) + read_imm8s()?)?
-        },
-        129 | 137 | 145 | 153 | 161 | 169 | 177 | 185 => {
-            get_seg_prefix_ds(read_reg32(ECX) + read_imm32s()?)?
-        },
-        2 | 10 | 18 | 26 | 34 | 42 | 50 | 58 => get_seg_prefix_ds(read_reg32(EDX))?,
-        66 | 74 | 82 | 90 | 98 | 106 | 114 | 122 => {
-            get_seg_prefix_ds(read_reg32(EDX) + read_imm8s()?)?
-        },
-        130 | 138 | 146 | 154 | 162 | 170 | 178 | 186 => {
-            get_seg_prefix_ds(read_reg32(EDX) + read_imm32s()?)?
-        },
-        3 | 11 | 19 | 27 | 35 | 43 | 51 | 59 => get_seg_prefix_ds(read_reg32(EBX))?,
-        67 | 75 | 83 | 91 | 99 | 107 | 115 | 123 => {
-            get_seg_prefix_ds(read_reg32(EBX) + read_imm8s()?)?
-        },
-        131 | 139 | 147 | 155 | 163 | 171 | 179 | 187 => {
-            get_seg_prefix_ds(read_reg32(EBX) + read_imm32s()?)?
-        },
-        4 | 12 | 20 | 28 | 36 | 44 | 52 | 60 => resolve_sib(false)?,
-        68 | 76 | 84 | 92 | 100 | 108 | 116 | 124 => resolve_sib(true)? + read_imm8s()?,
-        132 | 140 | 148 | 156 | 164 | 172 | 180 | 188 => resolve_sib(true)? + read_imm32s()?,
-        5 | 13 | 21 | 29 | 37 | 45 | 53 | 61 => get_seg_prefix_ds(read_imm32s()?)?,
-        69 | 77 | 85 | 93 | 101 | 109 | 117 | 125 => {
-            get_seg_prefix_ss(read_reg32(EBP) + read_imm8s()?)?
-        },
-        133 | 141 | 149 | 157 | 165 | 173 | 181 | 189 => {
-            get_seg_prefix_ss(read_reg32(EBP) + read_imm32s()?)?
-        },
-        6 | 14 | 22 | 30 | 38 | 46 | 54 | 62 => get_seg_prefix_ds(read_reg32(ESI))?,
-        70 | 78 | 86 | 94 | 102 | 110 | 118 | 126 => {
-            get_seg_prefix_ds(read_reg32(ESI) + read_imm8s()?)?
-        },
-        134 | 142 | 150 | 158 | 166 | 174 | 182 | 190 => {
-            get_seg_prefix_ds(read_reg32(ESI) + read_imm32s()?)?
-        },
-        7 | 15 | 23 | 31 | 39 | 47 | 55 | 63 => get_seg_prefix_ds(read_reg32(EDI))?,
-        71 | 79 | 87 | 95 | 103 | 111 | 119 | 127 => {
-            get_seg_prefix_ds(read_reg32(EDI) + read_imm8s()?)?
-        },
-        135 | 143 | 151 | 159 | 167 | 175 | 183 | 191 => {
-            get_seg_prefix_ds(read_reg32(EDI) + read_imm32s()?)?
-        },
+    match modrm_byte & !0o070 {
+        0o000 => get_seg_prefix_ds(read_reg32(EAX)),
+        0o100 => get_seg_prefix_ds(read_reg32(EAX) + read_imm8s()?),
+        0o200 => get_seg_prefix_ds(read_reg32(EAX) + read_imm32s()?),
+        0o001 => get_seg_prefix_ds(read_reg32(ECX)),
+        0o101 => get_seg_prefix_ds(read_reg32(ECX) + read_imm8s()?),
+        0o201 => get_seg_prefix_ds(read_reg32(ECX) + read_imm32s()?),
+        0o002 => get_seg_prefix_ds(read_reg32(EDX)),
+        0o102 => get_seg_prefix_ds(read_reg32(EDX) + read_imm8s()?),
+        0o202 => get_seg_prefix_ds(read_reg32(EDX) + read_imm32s()?),
+        0o003 => get_seg_prefix_ds(read_reg32(EBX)),
+        0o103 => get_seg_prefix_ds(read_reg32(EBX) + read_imm8s()?),
+        0o203 => get_seg_prefix_ds(read_reg32(EBX) + read_imm32s()?),
+        0o004 => resolve_sib(false),
+        0o104 => Ok(resolve_sib(true)? + read_imm8s()?),
+        0o204 => Ok(resolve_sib(true)? + read_imm32s()?),
+        0o005 => get_seg_prefix_ds(read_imm32s()?),
+        0o105 => get_seg_prefix_ss(read_reg32(EBP) + read_imm8s()?),
+        0o205 => get_seg_prefix_ss(read_reg32(EBP) + read_imm32s()?),
+        0o006 => get_seg_prefix_ds(read_reg32(ESI)),
+        0o106 => get_seg_prefix_ds(read_reg32(ESI) + read_imm8s()?),
+        0o206 => get_seg_prefix_ds(read_reg32(ESI) + read_imm32s()?),
+        0o007 => get_seg_prefix_ds(read_reg32(EDI)),
+        0o107 => get_seg_prefix_ds(read_reg32(EDI) + read_imm8s()?),
+        0o207 => get_seg_prefix_ds(read_reg32(EDI) + read_imm32s()?),
         _ => {
             dbg_assert!(false);
             0
         },
-    })
+    }
 }

From c64bbb0251ef49ea807d9ad6a69625af446513bf Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sat, 21 Sep 2024 11:35:08 -0600
Subject: [PATCH 18/23] use std::hint::unreachable_unchecked to reduce code
 size

---
 src/rust/cpu/modrm.rs |  4 ++--
 src/rust/jit.rs       | 10 +++++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/rust/cpu/modrm.rs b/src/rust/cpu/modrm.rs
index af085a0747..67fe2da721 100644
--- a/src/rust/cpu/modrm.rs
+++ b/src/rust/cpu/modrm.rs
@@ -29,7 +29,7 @@ pub unsafe fn resolve_modrm16(modrm_byte: i32) -> OrPageFault<i32> {
         0o207 => get_seg_prefix_ds(read_reg16(BX) + read_imm16()? & 0xFFFF),
         _ => {
             dbg_assert!(false);
-            0
+            std::hint::unreachable_unchecked()
         },
     }
 }
@@ -127,7 +127,7 @@ pub unsafe fn resolve_modrm32(modrm_byte: i32) -> OrPageFault<i32> {
         0o207 => get_seg_prefix_ds(read_reg32(EDI) + read_imm32s()?),
         _ => {
             dbg_assert!(false);
-            0
+            std::hint::unreachable_unchecked()
         },
     }
 }
diff --git a/src/rust/jit.rs b/src/rust/jit.rs
index 8dd5d8a6f9..b1d782b331 100644
--- a/src/rust/jit.rs
+++ b/src/rust/jit.rs
@@ -310,7 +310,15 @@ pub struct JitContext<'a> {
     pub instruction_counter: WasmLocal,
 }
 impl<'a> JitContext<'a> {
-    pub fn reg(&self, i: u32) -> WasmLocal { self.register_locals[i as usize].unsafe_clone() }
+    pub fn reg(&self, i: u32) -> WasmLocal {
+        match self.register_locals.get(i as usize) {
+            Some(x) => x.unsafe_clone(),
+            None => {
+                dbg_assert!(false);
+                unsafe { std::hint::unreachable_unchecked() }
+            },
+        }
+    }
 }
 
 pub const JIT_INSTR_BLOCK_BOUNDARY_FLAG: u32 = 1 << 0;

From e736e635f40c4fe36a0269349a3b0d8b83455683 Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sat, 21 Sep 2024 14:46:21 -0600
Subject: [PATCH 19/23] use virtio-net for arch profile

---
 src/browser/main.js | 6 +++++-
 src/virtio_net.js   | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/browser/main.js b/src/browser/main.js
index f952e7e838..d48b9056b8 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -149,6 +149,7 @@
                 filesystem: {
                     baseurl: host + "arch/",
                 },
+                net_device_type: "virtio",
             },
             {
                 id: "archlinux-boot",
@@ -170,6 +171,7 @@
                     "init=/usr/bin/init-openrc net.ifnames=0 biosdevname=0",
                 ].join(" "),
                 bzimage_initrd_from_filesystem: true,
+                net_device_type: "virtio",
             },
             {
                 id: "copy/skiffos",
@@ -1498,6 +1500,7 @@
             settings.memory_size = profile.memory_size;
             settings.vga_memory_size = profile.vga_memory_size;
             settings.boot_order = profile.boot_order;
+            settings.net_device_type = profile.net_device_type;
 
             if(!DEBUG && profile.homepage)
             {
@@ -1570,6 +1573,7 @@
 
                 settings.acpi = query_args.has("acpi") ? bool_arg(query_args.get("acpi")) : undefined;
                 settings.use_bochs_bios = query_args.get("bios") === "bochs";
+                settings.net_device_type = query_args.get("net_device_type") === "virtio" ? "virtio" : "ne2k";
             }
 
             settings.relay_url = query_args.get("relay_url");
@@ -1692,7 +1696,7 @@
         const emulator = new V86({
             screen_container: $("screen_container"),
             net_device: {
-                type: "ne2k",
+                type: settings.net_device_type || "ne2k",
                 relay_url: settings.relay_url,
             },
             autostart: true,
diff --git a/src/virtio_net.js b/src/virtio_net.js
index b8e5a4f79c..eb972986a3 100644
--- a/src/virtio_net.js
+++ b/src/virtio_net.js
@@ -101,6 +101,7 @@ function VirtioNet(cpu, bus, preserve_mac_from_state_image)
                         const buffer = new Uint8Array(bufchain.length_readable);
                         bufchain.get_next_blob(buffer);
                         this.bus.send("net" + this.id + "-send", buffer.subarray(12));
+                        this.bus.send("eth-transmit-end", [buffer.length - 12]);
                         this.virtio.queues[queue_id].push_reply(bufchain);
                     }
                     this.virtio.queues[queue_id].flush_replies();
@@ -188,6 +189,7 @@ function VirtioNet(cpu, bus, preserve_mac_from_state_image)
     });
 
     this.bus.register("net" + this.id + "-receive", data => {
+        this.bus.send("eth-receive-end", [data.length]);
         const with_header = new Uint8Array(12 + data.byteLength);
         const view = new DataView(with_header.buffer, with_header.byteOffset, with_header.byteLength);
         view.setInt16(10, 1);

From c758d6da40c79d8ee648e00ff66ee66e44b33501 Mon Sep 17 00:00:00 2001
From: chschnell <cs@rekoba.de>
Date: Sat, 21 Sep 2024 16:12:00 -0600
Subject: [PATCH 20/23] vga: handle character map select register and writes to
 font data

---
 src/vga.js | 69 +++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 53 insertions(+), 16 deletions(-)

diff --git a/src/vga.js b/src/vga.js
index c8afcff402..5b1e63656f 100644
--- a/src/vga.js
+++ b/src/vga.js
@@ -276,6 +276,7 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
     this.sequencer_memory_mode = 0;
     this.clocking_mode = 0;
     this.graphics_index = -1;
+    this.character_map_select = 0;
 
     this.plane_read = 0; // value 0-3, which plane to read
     this.planar_mode = 0;
@@ -323,23 +324,22 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
 
     io.register_read(0x3CC, this, this.port3CC_read);
 
-    io.register_write(0x3D4, this, this.port3D4_write, value => {
-        this.port3D4_write(value & 0xFF);
-        this.port3D5_write(value >> 8 & 0xFF);
-    });
-    io.register_write(0x3D5, this, this.port3D5_write, value => {
-        dbg_log("16-bit write to 3D5: " + h(value, 4), LOG_VGA);
-        this.port3D5_write(value & 0xFF);
-    });
+    io.register_write(0x3D4, this, this.port3D4_write, this.port3D4_write16);
+    io.register_write(0x3D5, this, this.port3D5_write, this.port3D5_write16);
 
     io.register_read(0x3D4, this, this.port3D4_read);
-    io.register_read(0x3D5, this, this.port3D5_read, () => {
-        dbg_log("Warning: 16-bit read from 3D5", LOG_VGA);
-        return this.port3D5_read();
-    });
+    io.register_read(0x3D5, this, this.port3D5_read, this.port3D5_read16);
+
+    // use same handlers for monochrome text-mode's alternate port addresses 0x3B4/0x3B5 as for the regular addresses (0x3D4/0x3D5)
+    io.register_write(0x3B4, this, this.port3D4_write, this.port3D4_write16);
+    io.register_write(0x3B5, this, this.port3D5_write, this.port3D5_write16);
+
+    io.register_read(0x3B4, this, this.port3D4_read);
+    io.register_read(0x3B5, this, this.port3D5_read, this.port3D5_read16);
 
     io.register_read(0x3CA, this, function() { dbg_log("3CA read", LOG_VGA); return 0; });
 
+    // use same handler for monochrome text-mode's alternate port address 0x3BA as for its regular address (0x3DA)
     io.register_read(0x3DA, this, this.port3DA_read);
     io.register_read(0x3BA, this, this.port3DA_read);
 
@@ -447,6 +447,7 @@ VGAScreen.prototype.get_state = function()
     state[60] = this.line_compare;
     state[61] = this.pixel_buffer;
     state[62] = this.dac_mask;
+    state[63] = this.character_map_select;
 
     return state;
 };
@@ -516,6 +517,7 @@ VGAScreen.prototype.set_state = function(state)
     this.line_compare = state[60];
     state[61] && this.pixel_buffer.set(state[61]);
     this.dac_mask = state[62] === undefined ? 0xFF : state[62];
+    this.character_map_select = state[63] === undefined ? 0 : state[63];
 
     this.screen.set_mode(this.graphical_mode);
 
@@ -600,8 +602,9 @@ VGAScreen.prototype.vga_memory_read = function(addr)
         var plane = this.plane_read;
         if(!this.graphical_mode)
         {
-            // We currently put all text data linearly
-            plane = 0;
+            // We store all text data linearly and font data in plane 2.
+            // TODO: works well for planes 0 and 2, but what about plane 1?
+            plane &= 0x3;
         }
         else if(this.sequencer_memory_mode & 0x8)
         {
@@ -645,7 +648,7 @@ VGAScreen.prototype.vga_memory_write = function(addr, value)
     {
         if(!(this.plane_write_bm & 0x3))
         {
-            // Ignore writes to font planes.
+            this.plane2[addr] = value;
             return;
         }
         this.vga_memory_write_text_mode(addr, value);
@@ -1520,7 +1523,20 @@ VGAScreen.prototype.port3C5_write = function(value)
             break;
         case 0x02:
             dbg_log("plane write mask: " + h(value), LOG_VGA);
+            var previous_plane_write_bm = this.plane_write_bm;
             this.plane_write_bm = value;
+            if(this.graphical_text && previous_plane_write_bm !== 0xf && (previous_plane_write_bm & 0x4) && !(this.plane_write_bm & 0x4))
+            {
+                // End of font plane 2 write access (initial value of plane_write_bm assumed to be 0xf)
+            }
+            break;
+        case 0x03:
+            dbg_log("character map select: " + h(value), LOG_VGA);
+            var previous_character_map_select = this.character_map_select;
+            this.character_map_select = value;
+            if(this.graphical_text && previous_character_map_select !== this.character_map_select)
+            {
+            }
             break;
         case 0x04:
             dbg_log("sequencer memory mode: " + h(value), LOG_VGA);
@@ -1541,6 +1557,8 @@ VGAScreen.prototype.port3C5_read = function()
             return this.clocking_mode;
         case 0x02:
             return this.plane_write_bm;
+        case 0x03:
+            return this.character_map_select;
         case 0x04:
             return this.sequencer_memory_mode;
         case 0x06:
@@ -1759,6 +1777,12 @@ VGAScreen.prototype.port3D4_write = function(register)
     this.index_crtc = register;
 };
 
+VGAScreen.prototype.port3D4_write16 = function(register)
+{
+    this.port3D4_write(register & 0xFF);
+    this.port3D5_write(register >> 8 & 0xFF);
+};
+
 VGAScreen.prototype.port3D4_read = function()
 {
     dbg_log("3D4 read / crtc index: " + this.index_crtc, LOG_VGA);
@@ -1816,12 +1840,13 @@ VGAScreen.prototype.port3D5_write = function(value)
             break;
         case 0x9:
             dbg_log("3D5 / max scan line write: " + h(value), LOG_VGA);
+            var previous_max_scan_line = this.max_scan_line;
             this.max_scan_line = value;
             this.line_compare = (this.line_compare & 0x1FF) | (value << 3 & 0x200);
 
             var previous_vertical_blank_start = this.vertical_blank_start;
             this.vertical_blank_start = (this.vertical_blank_start & 0x1FF) | (value << 4 & 0x200);
-            if(previous_vertical_blank_start !== this.vertical_blank_start)
+            if(((previous_max_scan_line ^ this.max_scan_line) & 0x9F) || previous_vertical_blank_start !== this.vertical_blank_start)
             {
                 this.update_vga_size();
             }
@@ -1956,6 +1981,12 @@ VGAScreen.prototype.port3D5_write = function(value)
 
 };
 
+VGAScreen.prototype.port3D5_write16 = function(register)
+{
+    dbg_log("16-bit write to 3D5: " + h(register, 4), LOG_VGA);
+    this.port3D5_write(register & 0xFF);
+};
+
 VGAScreen.prototype.port3D5_read = function()
 {
     dbg_log("3D5 read " + h(this.index_crtc), LOG_VGA);
@@ -2011,6 +2042,12 @@ VGAScreen.prototype.port3D5_read = function()
     }
 };
 
+VGAScreen.prototype.port3D5_read16 = function()
+{
+    dbg_log("Warning: 16-bit read from 3D5", LOG_VGA);
+    return this.port3D5_read();
+};
+
 VGAScreen.prototype.port3DA_read = function()
 {
     dbg_log("3DA read - status 1 and clear attr index", LOG_VGA);

From c1ef7144542d9f03a2150bad27e7525b481a136c Mon Sep 17 00:00:00 2001
From: Fabian <copy@copy.sh>
Date: Sat, 21 Sep 2024 16:14:50 -0600
Subject: [PATCH 21/23] serial test: log data if test times out

---
 tests/api/serial.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/api/serial.js b/tests/api/serial.js
index 84132b8964..88ab4c3a79 100755
--- a/tests/api/serial.js
+++ b/tests/api/serial.js
@@ -34,6 +34,7 @@ setTimeout(async () =>
 }, 1000);
 
 const timeout = setTimeout(() => {
+    console.log(serial_data);
     throw new Error("Timeout");
 }, 60 * 1000);
 

From f92e6b4b55c3f6e5a327b836375df20fedd45fa4 Mon Sep 17 00:00:00 2001
From: chschnell <cs@rekoba.de>
Date: Sat, 21 Sep 2024 19:08:38 -0600
Subject: [PATCH 22/23] Add VGA graphical text mode

---
 Makefile               |   2 +-
 debug.html             |   1 +
 src/browser/main.js    |   5 +-
 src/browser/screen.js  |  18 +-
 src/browser/starter.js |   4 +-
 src/cpu.js             |   2 +-
 src/vga.js             | 110 +++++++-
 src/vga_text.js        | 628 +++++++++++++++++++++++++++++++++++++++++
 8 files changed, 747 insertions(+), 23 deletions(-)
 create mode 100644 src/vga_text.js

diff --git a/Makefile b/Makefile
index 892b1fe07e..bba402d2a4 100644
--- a/Makefile
+++ b/Makefile
@@ -79,7 +79,7 @@ CARGO_FLAGS_SAFE=\
 CARGO_FLAGS=$(CARGO_FLAGS_SAFE) -C target-feature=+bulk-memory -C target-feature=+multivalue -C target-feature=+simd128
 
 CORE_FILES=const.js config.js io.js main.js lib.js buffer.js ide.js pci.js floppy.js \
-	   memory.js dma.js pit.js vga.js ps2.js rtc.js uart.js \
+	   memory.js dma.js pit.js vga.js vga_text.js ps2.js rtc.js uart.js \
 	   acpi.js apic.js ioapic.js \
 	   state.js ne2k.js sb16.js virtio.js virtio_console.js virtio_net.js \
 	   bus.js log.js cpu.js debug.js \
diff --git a/debug.html b/debug.html
index a4e2d20c1a..57594cb869 100644
--- a/debug.html
+++ b/debug.html
@@ -20,6 +20,7 @@
 <script src="src/dma.js"></script>
 <script src="src/pit.js"></script>
 <script src="src/vga.js"></script>
+<script src="src/vga_text.js"></script>
 <script src="src/ps2.js"></script>
 <script src="src/rtc.js"></script>
 <script src="src/uart.js"></script>
diff --git a/src/browser/main.js b/src/browser/main.js
index d48b9056b8..bdabbb2256 100644
--- a/src/browser/main.js
+++ b/src/browser/main.js
@@ -1694,7 +1694,10 @@
         }
 
         const emulator = new V86({
-            screen_container: $("screen_container"),
+            screen: {
+                container: $("screen_container"),
+                use_graphical_text: false,
+            },
             net_device: {
                 type: settings.net_device_type || "ne2k",
                 relay_url: settings.relay_url,
diff --git a/src/browser/screen.js b/src/browser/screen.js
index df8945139d..176ae429e3 100644
--- a/src/browser/screen.js
+++ b/src/browser/screen.js
@@ -37,7 +37,7 @@ function ScreenAdapter(options, screen_fill_buffer)
         changed_rows,
 
         // are we in graphical mode now?
-        is_graphical = false,
+        is_graphical = !!options.use_graphical_text,
 
         // Index 0: ASCII code
         // Index 1: Blinking
@@ -134,9 +134,19 @@ function ScreenAdapter(options, screen_fill_buffer)
 
     this.init = function()
     {
-        // not necessary, because this gets initialized by the bios early,
-        // but nicer to look at
-        this.set_size_text(80, 25);
+        // initialize with mode and size presets as expected by the bios
+        // to avoid flickering during early startup
+        this.set_mode(is_graphical);
+
+        if(is_graphical)
+        {
+            // assume 80x25 with 9x16 font
+            this.set_size_graphical(720, 400, 720, 400);
+        }
+        else
+        {
+            this.set_size_text(80, 25);
+        }
 
         this.timer();
     };
diff --git a/src/browser/starter.js b/src/browser/starter.js
index 154ae3e4f4..5813c1fa97 100644
--- a/src/browser/starter.js
+++ b/src/browser/starter.js
@@ -305,6 +305,7 @@ V86.prototype.continue_init = async function(emulator, options)
     settings.cpuid_level = options.cpuid_level;
     settings.virtio_console = options.virtio_console;
     settings.virtio_net = options.virtio_net;
+    settings.screen_options = options.screen_options;
 
     const relay_url = options.network_relay_url || options.net_device && options.net_device.relay_url;
     if(relay_url)
@@ -345,13 +346,14 @@ V86.prototype.continue_init = async function(emulator, options)
 
     if(screen_options.container)
     {
-        this.screen_adapter = new ScreenAdapter(screen_options, () => this.v86.cpu.devices.vga.screen_fill_buffer());
+        this.screen_adapter = new ScreenAdapter(screen_options, () => this.v86.cpu.devices.vga && this.v86.cpu.devices.vga.screen_fill_buffer());
     }
     else
     {
         this.screen_adapter = new DummyScreenAdapter();
     }
     settings.screen = this.screen_adapter;
+    settings.screen_options = screen_options;
 
     if(options.serial_container)
     {
diff --git a/src/cpu.js b/src/cpu.js
index c81759fd42..c1b6210ed0 100644
--- a/src/cpu.js
+++ b/src/cpu.js
@@ -940,7 +940,7 @@ CPU.prototype.init = function(settings, device_bus)
 
         this.devices.dma = new DMA(this);
 
-        this.devices.vga = new VGAScreen(this, device_bus, settings.screen, settings.vga_memory_size || 8 * 1024 * 1024);
+        this.devices.vga = new VGAScreen(this, device_bus, settings.screen, settings.vga_memory_size || 8 * 1024 * 1024, settings.screen_options || {});
 
         this.devices.ps2 = new PS2(this, device_bus);
 
diff --git a/src/vga.js b/src/vga.js
index 5b1e63656f..2f34ccb738 100644
--- a/src/vga.js
+++ b/src/vga.js
@@ -50,8 +50,9 @@ const VGA_HOST_MEMORY_SPACE_SIZE = Uint32Array.from([
  * @param {BusConnector} bus
  * @param {ScreenAdapter|DummyScreenAdapter} screen
  * @param {number} vga_memory_size
+ * @param {Object} options
  */
-function VGAScreen(cpu, bus, screen, vga_memory_size)
+function VGAScreen(cpu, bus, screen, vga_memory_size, options)
 {
     this.cpu = cpu;
 
@@ -166,7 +167,6 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
 
     /** @type {boolean} */
     this.graphical_mode = false;
-    this.screen.set_mode(this.graphical_mode);
 
     /*
      * VGA palette containing 256 colors for video mode 13, svga 8bpp, etc.
@@ -377,9 +377,41 @@ function VGAScreen(cpu, bus, screen, vga_memory_size)
         (addr, value) => this.vga_memory_write(addr, value),
     );
 
+    if(options.use_graphical_text)
+    {
+        this.graphical_text = new GraphicalText(this);
+    }
+
     cpu.devices.pci.register_device(this);
 }
 
+VGAScreen.prototype.grab_text_content = function(keep_whitespace)
+{
+    var addr = this.start_address << 1;
+    const split_screen_row = this.scan_line_to_screen_row(this.line_compare);
+    const row_offset = Math.max(0, (this.offset_register * 2 - this.max_cols) * 2);
+    const text_rows = [];
+
+    for(var row = 0; row < this.max_rows; row++)
+    {
+        if(row === split_screen_row)
+        {
+            addr = 0;
+        }
+
+        let line = "";
+        for(var col = 0; col < this.max_cols; col++, addr += 2)
+        {
+            line += String.fromCodePoint(this.vga_memory[addr]);
+        }
+
+        text_rows.push(keep_whitespace ? line : line.trimEnd());
+        addr += row_offset;
+    }
+
+    return text_rows;
+};
+
 VGAScreen.prototype.get_state = function()
 {
     var state = [];
@@ -519,7 +551,7 @@ VGAScreen.prototype.set_state = function(state)
     this.dac_mask = state[62] === undefined ? 0xFF : state[62];
     this.character_map_select = state[63] === undefined ? 0 : state[63];
 
-    this.screen.set_mode(this.graphical_mode);
+    this.screen.set_mode(this.graphical_mode || !!this.graphical_text);
 
     if(this.graphical_mode)
     {
@@ -823,6 +855,11 @@ VGAScreen.prototype.apply_bitmask = function(data_dword, bitmask_dword)
 
 VGAScreen.prototype.text_mode_redraw = function()
 {
+    if(this.graphical_text)
+    {
+        return;
+    }
+
     const split_screen_row = this.scan_line_to_screen_row(this.line_compare);
     const row_offset = Math.max(0, (this.offset_register * 2 - this.max_cols) * 2);
     const blink_flag = this.attribute_mode & 1 << 3;
@@ -898,15 +935,23 @@ VGAScreen.prototype.vga_memory_write_text_mode = function(addr, value)
         chr = value;
         color = this.vga_memory[addr | 1];
     }
+
     const blink_flag = this.attribute_mode & 1 << 3;
     const blinking = blink_flag && (color & 1 << 7);
     const bg_color_mask = blink_flag ? 7 : 0xF;
 
     this.bus.send("screen-put-char", [row, col, chr]);
 
-    this.screen.put_char(row, col, chr, blinking,
-        this.vga256_palette[this.dac_mask & this.dac_map[color >> 4 & bg_color_mask]],
-        this.vga256_palette[this.dac_mask & this.dac_map[color & 0xF]]);
+    if(this.graphical_text)
+    {
+        this.graphical_text.invalidate_row(row);
+    }
+    else
+    {
+        this.screen.put_char(row, col, chr, blinking,
+            this.vga256_palette[this.dac_mask & this.dac_map[color >> 4 & bg_color_mask]],
+            this.vga256_palette[this.dac_mask & this.dac_map[color & 0xF]]);
+    }
 };
 
 VGAScreen.prototype.update_cursor = function()
@@ -927,9 +972,16 @@ VGAScreen.prototype.update_cursor = function()
     }
 
     dbg_assert(row >= 0 && col >= 0);
-
     // NOTE: is allowed to be out of bounds
-    this.screen.update_cursor(row, col);
+
+    if(this.graphical_text)
+    {
+        this.graphical_text.set_cursor_pos(row, col);
+    }
+    else
+    {
+        this.screen.update_cursor(row, col);
+    }
 };
 
 VGAScreen.prototype.complete_redraw = function()
@@ -1122,8 +1174,16 @@ VGAScreen.prototype.set_size_text = function(cols_count, rows_count)
     this.max_cols = cols_count;
     this.max_rows = rows_count;
 
-    this.screen.set_size_text(cols_count, rows_count);
     this.bus.send("screen-set-size", [cols_count, rows_count, 0]);
+
+    if(this.graphical_text)
+    {
+        this.graphical_text.set_size(rows_count, cols_count);
+    }
+    else
+    {
+        this.screen.set_size_text(cols_count, rows_count);
+    }
 };
 
 VGAScreen.prototype.set_size_graphical = function(width, height, virtual_width, virtual_height, bpp)
@@ -1341,7 +1401,15 @@ VGAScreen.prototype.update_cursor_scanline = function()
     const start = Math.min(max, this.cursor_scanline_start & 0x1F);
     const end = Math.min(max, this.cursor_scanline_end & 0x1F);
     const visible = !disabled && start < end;
-    this.screen.update_cursor_scanline(start, end, visible);
+
+    if(this.graphical_text)
+    {
+        this.graphical_text.set_cursor_attr(start, end, visible);
+    }
+    else
+    {
+        this.screen.update_cursor_scanline(start, end, visible);
+    }
 };
 
 /**
@@ -1388,11 +1456,11 @@ VGAScreen.prototype.port3C0_write = function(value)
                     var previous_mode = this.attribute_mode;
                     this.attribute_mode = value;
 
-                    var is_graphical = (value & 0x1) > 0;
+                    const is_graphical = (value & 0x1) !== 0;
                     if(!this.svga_enabled && this.graphical_mode !== is_graphical)
                     {
                         this.graphical_mode = is_graphical;
-                        this.screen.set_mode(this.graphical_mode);
+                        this.screen.set_mode(this.graphical_mode || !!this.graphical_text);
                     }
 
                     if((previous_mode ^ value) & 0x40)
@@ -1528,6 +1596,7 @@ VGAScreen.prototype.port3C5_write = function(value)
             if(this.graphical_text && previous_plane_write_bm !== 0xf && (previous_plane_write_bm & 0x4) && !(this.plane_write_bm & 0x4))
             {
                 // End of font plane 2 write access (initial value of plane_write_bm assumed to be 0xf)
+                this.graphical_text.invalidate_font_shape();
             }
             break;
         case 0x03:
@@ -1536,6 +1605,7 @@ VGAScreen.prototype.port3C5_write = function(value)
             this.character_map_select = value;
             if(this.graphical_text && previous_character_map_select !== this.character_map_select)
             {
+                this.graphical_text.set_character_map(this.character_map_select);
             }
             break;
         case 0x04:
@@ -2425,9 +2495,19 @@ VGAScreen.prototype.screen_fill_buffer = function()
     if(!this.graphical_mode)
     {
         // text mode
-        // Update retrace behaviour anyway - programs waiting for signal before
-        // changing to graphical mode
-        this.update_vertical_retrace();
+        if(this.graphical_text)
+        {
+            const image_data = this.graphical_text.render();
+            this.screen.update_buffer([{
+                image_data: image_data,
+                screen_x: 0,
+                screen_y: 0,
+                buffer_x: 0,
+                buffer_y: 0,
+                buffer_width: image_data.width,
+                buffer_height: image_data.height
+            }]);
+        }
         return;
     }
 
diff --git a/src/vga_text.js b/src/vga_text.js
new file mode 100644
index 0000000000..5b5949b038
--- /dev/null
+++ b/src/vga_text.js
@@ -0,0 +1,628 @@
+/*
+vga_text.js
+
+Renders text to image buffer using VGA fonts and attributes.
+*/
+"use strict";
+
+/**
+ * @constructor
+ * @param {VGAScreen} vga
+ */
+function GraphicalText(vga)
+{
+    this.vga = vga;
+
+    /**
+     * Number of text columns
+     * @type {number}
+     */
+    this.txt_width = 80;
+
+    /**
+     * Number of text rows
+     * @type {number}
+     */
+    this.txt_height = 25;
+
+    /**
+     * If true then at least one row in txt_row_dirty is marked as modified
+     * @type{number}
+     */
+    this.txt_dirty = 0;
+
+    /**
+     * One bool per row, row was modified if its entry is != 0
+     */
+    this.txt_row_dirty = new Uint8Array(this.txt_height);
+
+    /**
+     * Font bitmaps in VGA memory were changed if true
+     * @type{boolean}
+     */
+    this.font_data_dirty = false;
+
+    /**
+     * Font width in pixel (8, 9 or 16)
+     * @type {number}
+     */
+    this.font_width = 9;
+
+    /**
+     * Font height in pixel (0...32)
+     * @type {number}
+     */
+    this.font_height = 16;
+
+    /**
+     * Duplicate 8th to 9th column in horizontal line drawing characters if true (Line Graphics Enable)
+     * @type{boolean}
+     */
+    this.font_lge = false;
+
+    /**
+     * Flat bitmap of 8 fonts, array of size: 8 * 256 * font_width * font_height
+     * @type{Uint8ClampedArray<number>}
+     */
+    this.font_bitmap = new Uint8ClampedArray(8 * 256 * this.font_width * this.font_height);
+
+    /**
+     * True: blink when msb (0x80) of text attribute is set (8 background colors)
+     * False: msb selects background intensity (16 background colors)
+     * @type{boolean}
+     */
+    this.font_blink_enabled = false;
+
+    /**
+     * Active index (0...7) of font A
+     * @type {number}
+     */
+    this.font_index_A = 0;
+
+    /**
+     * Active index (0...7) of font B (TODO)
+     * @type {number}
+     */
+    this.font_index_B = 0;
+
+    /**
+     * If true then cursor_enabled_latch, cursor_top_latch and cursor_bottom_latch were overwritten since last call to render().
+     * @type{boolean}
+     */
+    this.cursor_attr_dirty = false;
+
+    /**
+     * Latest value for cursor_enabled if cursor_attr_dirty is true
+     * @type{boolean}
+     */
+    this.cursor_enabled_latch = false;
+
+    /**
+     * Latest value for cursor_top_latch if cursor_attr_dirty is true
+     * @type {number}
+     */
+    this.cursor_top_latch = 0;
+
+    /**
+     * Latest value for cursor_bottom_latch if cursor_attr_dirty is true
+     * @type {number}
+     */
+    this.cursor_bottom_latch = 0;
+
+    /**
+     * If true then cursor_row_latch and cursor_col_latch were overwritten since last call to render().
+     * @type{boolean}
+     */
+    this.cursor_pos_dirty = false;
+
+    /**
+     * Latest value for cursor_row if cursor_pos_dirty is true
+     * @type {number}
+     */
+    this.cursor_row_latch = 0;
+
+    /**
+     * Latest value for cursor_col if cursor_pos_dirty is true
+     * @type {number}
+     */
+    this.cursor_col_latch = 0;
+
+    /**
+     * Emulate cursor if true, else disable cursor
+     * @type{boolean}
+     */
+    this.cursor_enabled = false;
+
+    /**
+     * Cursor position's row (0...txt_height-1)
+     * @type {number}
+     */
+    this.cursor_row = 0;
+
+    /**
+     * Cursor position's column (0...txt_width-1)
+     * @type {number}
+     */
+    this.cursor_col = 0;
+
+    /**
+     * Cursor box's top scanline (0...font_height)
+     * @type {number}
+     */
+    this.cursor_top = 0;
+
+    /**
+     * Cursor box's bottom scanline (0...font_height, inclusive)
+     * @type {number}
+     */
+    this.cursor_bottom = 0;
+
+    /**
+     * Tracked value of register vga.attribute_mode
+     * @type {number}
+     */
+    this.vga_attribute_mode = 0;
+
+    /**
+     * Tracked value of register vga.clocking_mode
+     * @type {number}
+     */
+    this.vga_clocking_mode = 0;
+
+    /**
+     * Tracked value of register vga.max_scan_line
+     * @type {number}
+     */
+    this.vga_max_scan_line = 0;
+
+    /**
+     * Width of graphics canvas in pixel (txt_width * font_width)
+     * @type {number}
+     */
+    this.gfx_width = this.txt_width * this.font_width;
+
+    /**
+     * Height of graphics canvas in pixel (txt_height * font_height)
+     * @type {number}
+     */
+    this.gfx_height = this.txt_height * this.font_height;
+
+    /**
+     * Local screen bitmap buffer, array of size: gfx_width * gfx_height * 4
+     * @type{Uint8ClampedArray<number>}
+     */
+    this.gfx_data = new Uint8ClampedArray(this.gfx_width * this.gfx_height * 4);
+
+    /**
+     * Image container of local screen bitmap buffer gfx_data
+     * @type{ImageData}
+     */
+    this.image_data = new ImageData(this.gfx_data, this.gfx_width, this.gfx_height);
+
+    /**
+     * Show cursor and blinking text now if true (controlled by framerate counter)
+     * @type{boolean}
+     */
+    this.blink_visible = false;
+
+    /**
+     * Frame counter to control blink rate of type Uint32
+     * @type {number}
+     */
+    this.frame_count = 0;
+}
+
+GraphicalText.prototype.rebuild_font_bitmap = function(width_9px, width_double)
+{
+    const font_height = this.font_height;
+    const font_lge = this.font_lge;
+    const src_bitmap = this.vga.plane2;
+    const dst_bitmap = new Uint8ClampedArray(8 * 256 * this.font_width * font_height);
+    const vga_inc_chr = 32 - font_height;
+
+    let i_dst = 0;
+    const copy_bit = width_double ?
+        function(value)
+        {
+            dst_bitmap[i_dst++] = value;
+            dst_bitmap[i_dst++] = value;
+        } :
+        function(value)
+        {
+            dst_bitmap[i_dst++] = value;
+        };
+
+    let i_src = 0;
+    for(let i_font = 0; i_font < 8; ++i_font)
+    {
+        for(let i_chr = 0; i_chr < 256; ++i_chr, i_src += vga_inc_chr)
+        {
+            for(let i_line = 0; i_line < font_height; ++i_line)
+            {
+                const line_bits = src_bitmap[i_src++];
+                for(let i_bit = 0x80; i_bit > 0; i_bit >>= 1)
+                {
+                    copy_bit(line_bits & i_bit ? 1 : 0);
+                }
+                if(width_9px)
+                {
+                    copy_bit(font_lge && i_chr >= 0xC0 && i_chr <= 0xDF && line_bits & 1 ? 1 : 0);
+                }
+            }
+        }
+    }
+
+    return dst_bitmap;
+};
+
+GraphicalText.prototype.resize_canvas = function()
+{
+    this.txt_dirty = 1;
+    this.txt_row_dirty.fill(1);
+};
+
+GraphicalText.prototype.rebuild_image_data = function()
+{
+    const gfx_size = this.gfx_width * this.gfx_height * 4;
+    const gfx_data = new Uint8ClampedArray(gfx_size);
+    for(let i = 3; i < gfx_size; i += 4)
+    {
+        gfx_data[i] = 0xff;
+    }
+    this.gfx_data = gfx_data;
+    this.image_data = new ImageData(this.gfx_data, this.gfx_width, this.gfx_height);
+    this.resize_canvas();
+};
+
+GraphicalText.prototype.mark_blinking_rows_dirty = function()
+{
+    const vga_memory = this.vga.vga_memory;
+    const txt_row_dirty = this.txt_row_dirty;
+    const txt_width = this.txt_width;
+    const txt_height = this.txt_height;
+    const txt_row_size = txt_width * 2;
+    const txt_row_step = Math.max(0, (this.vga.offset_register * 2 - txt_width) * 2);
+    const split_screen_row = this.vga.scan_line_to_screen_row(this.vga.line_compare);
+    let row, col, txt_i = this.vga.start_address << 1;
+
+    for(row = 0; row < txt_height; ++row, txt_i += txt_row_step)
+    {
+        if(row === split_screen_row)
+        {
+            txt_i = 0;
+        }
+
+        if(txt_row_dirty[row])
+        {
+            txt_i += txt_row_size;
+            continue;
+        }
+
+        for(col = 0; col < txt_width; ++col, txt_i += 2)
+        {
+            if(vga_memory[txt_i | 1] & 0x80)
+            {
+                txt_row_dirty[row] = this.txt_dirty = 1;
+                txt_i += txt_row_size - col * 2;
+                break;
+            }
+        }
+    }
+};
+
+GraphicalText.prototype.render_dirty_rows = function()
+{
+    const vga = this.vga;
+    const vga_memory = vga.vga_memory;
+    const txt_width = this.txt_width;
+    const txt_height = this.txt_height;
+    const txt_row_dirty = this.txt_row_dirty;
+    const gfx_data = this.gfx_data;
+    const font_bitmap = this.font_bitmap;
+    const font_size = this.font_width * this.font_height;
+    const font_A_offset = this.font_index_A * 256;
+    const font_B_offset = this.font_index_B * 256;
+    const font_AB_enabled = font_A_offset !== font_B_offset;
+    const font_blink_enabled = this.font_blink_enabled;
+    //const blink_visible = this.blink_visible;
+    const blink_visible = true;
+    const cursor_visible = this.cursor_enabled && blink_visible;
+    const cursor_top = this.cursor_top;
+    const cursor_height = this.cursor_bottom - cursor_top + 1;
+
+    const split_screen_row = vga.scan_line_to_screen_row(vga.line_compare);
+    const bg_color_mask = font_blink_enabled ? 0x7 : 0xF;
+    const palette = new Int32Array(16);
+    for(let i = 0; i < 16; ++i)
+    {
+        palette[i] = vga.vga256_palette[vga.dac_mask & vga.dac_map[i]];
+    }
+
+    const txt_row_size = txt_width * 2;
+    const txt_row_step = Math.max(0, (vga.offset_register * 2 - txt_width) * 2);
+
+    const gfx_col_size = this.font_width * 4;                       // column size in gfx_data (tuple of 4 RGBA items)
+    const gfx_line_size = this.gfx_width * 4;                       // line size in gfx_data
+    const gfx_row_size = gfx_line_size * this.font_height;          // row size in gfx_data
+    const gfx_col_step = (this.font_width - this.font_height * this.gfx_width) * 4; // move from end of current column to start of next in gfx_data
+    const gfx_line_step = (this.gfx_width - this.font_width) * 4;   // move forward to start of column's next line in gfx_data
+
+    // int, current cursor linear position in canvas coordinates (top left of row/col)
+    const cursor_gfx_i = (this.cursor_row * this.gfx_width * this.font_height + this.cursor_col * this.font_width) * 4;
+
+    let txt_i, chr, chr_attr, chr_bg_rgba, chr_fg_rgba, chr_blinking, chr_font_ofs;
+    let fg, bg, fg_r=0, fg_g=0, fg_b=0, bg_r=0, bg_g=0, bg_b=0;
+    let gfx_i, gfx_end_y, gfx_end_x, glyph_i;
+    let draw_cursor, gfx_ic;
+    let row, col;
+
+    txt_i = vga.start_address << 1;
+
+    for(row = 0; row < txt_height; ++row, txt_i += txt_row_step)
+    {
+        if(row === split_screen_row)
+        {
+            txt_i = 0;
+        }
+
+        if(! txt_row_dirty[row])
+        {
+            txt_i += txt_row_size;
+            continue;
+        }
+
+        gfx_i = row * gfx_row_size;
+
+        for(col = 0; col < txt_width; ++col, txt_i += 2, gfx_i += gfx_col_step)
+        {
+            chr = vga_memory[txt_i];
+            chr_attr = vga_memory[txt_i | 1];
+            chr_blinking = font_blink_enabled && chr_attr & 0x80;
+            chr_font_ofs = font_AB_enabled ? (chr_attr & 0x8 ? font_A_offset : font_B_offset) : font_A_offset;
+            chr_bg_rgba = palette[chr_attr >> 4 & bg_color_mask];
+            chr_fg_rgba = palette[chr_attr & 0xF];
+
+            if(bg !== chr_bg_rgba)
+            {
+                bg = chr_bg_rgba;
+                bg_r = bg >> 16;
+                bg_g = (bg >> 8) & 0xff;
+                bg_b = bg & 0xff;
+            }
+
+            if(chr_blinking && ! blink_visible)
+            {
+                if(fg !== bg) {
+                    fg = bg;
+                    fg_r = bg_r;
+                    fg_g = bg_g;
+                    fg_b = bg_b;
+                }
+            }
+            else if(fg !== chr_fg_rgba)
+            {
+                fg = chr_fg_rgba;
+                fg_r = fg >> 16;
+                fg_g = (fg >> 8) & 0xff;
+                fg_b = fg & 0xff;
+            }
+
+            draw_cursor = cursor_visible && cursor_gfx_i === gfx_i;
+
+            glyph_i = (chr_font_ofs + chr) * font_size;
+
+            gfx_end_y = gfx_i + gfx_row_size;
+            for(; gfx_i < gfx_end_y; gfx_i += gfx_line_step)
+            {
+                gfx_end_x = gfx_i + gfx_col_size;
+                for(; gfx_i < gfx_end_x; gfx_i += 4)
+                {
+                    if(font_bitmap[glyph_i++])
+                    {
+                        gfx_data[gfx_i]   = fg_r;
+                        gfx_data[gfx_i+1] = fg_g;
+                        gfx_data[gfx_i+2] = fg_b;
+                    }
+                    else
+                    {
+                        gfx_data[gfx_i]   = bg_r;
+                        gfx_data[gfx_i+1] = bg_g;
+                        gfx_data[gfx_i+2] = bg_b;
+                    }
+                }
+            }
+
+            if(draw_cursor)
+            {
+                gfx_ic = cursor_gfx_i + cursor_top * gfx_line_size;
+                gfx_end_y = gfx_ic + cursor_height * gfx_line_size;
+                for(; gfx_ic < gfx_end_y; gfx_ic += gfx_line_step)
+                {
+                    gfx_end_x = gfx_ic + gfx_col_size;
+                    for(; gfx_ic < gfx_end_x; gfx_ic += 4)
+                    {
+                        gfx_data[gfx_ic]   = fg_r;
+                        gfx_data[gfx_ic+1] = fg_g;
+                        gfx_data[gfx_ic+2] = fg_b;
+                    }
+                }
+            }
+        }
+    }
+};
+
+//
+// Public methods
+//
+
+GraphicalText.prototype.mark_dirty = function()
+{
+    this.txt_row_dirty.fill(1);
+    this.txt_dirty = 1;
+};
+
+GraphicalText.prototype.invalidate_row = function(row)
+{
+    if(row >= 0 && row < this.txt_height)
+    {
+        this.txt_row_dirty[row] = this.txt_dirty = 1;
+    }
+};
+
+GraphicalText.prototype.invalidate_font_shape = function()
+{
+    this.font_data_dirty = true;
+};
+
+GraphicalText.prototype.set_size = function(rows, cols)
+{
+    if(rows > 0 && rows < 256 && cols > 0 && cols < 256)
+    {
+        this.txt_width = cols;
+        this.txt_height = rows;
+
+        this.gfx_width = this.txt_width * this.font_width;
+        this.gfx_height = this.txt_height * this.font_height;
+
+        this.txt_row_dirty = new Uint8Array(this.txt_height);
+        this.vga.screen.set_size_graphical(this.gfx_width, this.gfx_height, this.gfx_width, this.gfx_height);
+        this.mark_dirty();
+        this.rebuild_image_data();
+    }
+};
+
+GraphicalText.prototype.set_character_map = function(char_map_select)
+{
+    // bits 2, 3 and 5 (LSB to MSB): VGA font page index of font A
+    // bits 0, 1 and 4: VGA font page index of font B
+    // linear_index_map[] maps VGA's non-liner font page index to linear index
+    const linear_index_map = [0, 2, 4, 6, 1, 3, 5, 7];
+    const vga_index_A = ((char_map_select & 0b1100) >> 2) | ((char_map_select & 0b100000) >> 3);
+    const vga_index_B = (char_map_select & 0b11) | ((char_map_select & 0b10000) >> 2);
+    const font_index_A = linear_index_map[vga_index_A];
+    const font_index_B = linear_index_map[vga_index_B];
+
+    if(this.font_index_A !== font_index_A || this.font_index_B !== font_index_B)
+    {
+        this.font_index_A = font_index_A;
+        this.font_index_B = font_index_B;
+        this.mark_dirty();
+    }
+};
+
+GraphicalText.prototype.set_cursor_pos = function(row, col)
+{
+    this.cursor_pos_dirty = true;
+    this.cursor_row_latch = row;
+    this.cursor_col_latch = col;
+};
+
+GraphicalText.prototype.set_cursor_attr = function(start, end, visible)
+{
+    this.cursor_attr_dirty = true;
+    this.cursor_enabled_latch = !! visible;
+    this.cursor_top_latch = start;
+    this.cursor_bottom_latch = end;
+};
+
+GraphicalText.prototype.render = function()
+{
+    // increment Uint32 frame counter
+    this.frame_count = (this.frame_count + 1) >>> 0;
+
+    // apply changes to font_width, font_height, font_lge, font_bitmap and font_blink_enabled
+    const curr_clocking_mode = this.vga.clocking_mode & 0b00001001;
+    const curr_attribute_mode = this.vga.attribute_mode & 0b00001100;
+    const curr_max_scan_line = this.vga.max_scan_line & 0b10011111;
+    if(this.font_data_dirty ||
+            this.vga_clocking_mode !== curr_clocking_mode ||
+            this.vga_attribute_mode !== curr_attribute_mode ||
+            this.vga_max_scan_line !== curr_max_scan_line)
+    {
+        const width_9px = ! (curr_clocking_mode & 0x01);
+        const width_double = !! (curr_clocking_mode & 0x08);
+        const curr_font_width = (width_9px ? 9 : 8) * (width_double ? 2 : 1);
+        const curr_font_blink_enabled = !! (curr_attribute_mode & 0b00001000);
+        const curr_font_lge = !! (curr_attribute_mode & 0b00000100);
+        const curr_font_height = (curr_max_scan_line & 0b00011111) + 1;
+
+        const font_data_changed = this.font_data_dirty || this.font_lge !== curr_font_lge;
+        const font_size_changed = this.font_width !== curr_font_width || this.font_height !== curr_font_height;
+
+        this.font_data_dirty = false;
+        this.font_width = curr_font_width;
+        this.font_height = curr_font_height;
+        this.font_blink_enabled = curr_font_blink_enabled;
+        this.font_lge = curr_font_lge;
+
+        this.vga_clocking_mode = curr_clocking_mode;
+        this.vga_attribute_mode = curr_attribute_mode;
+        this.vga_max_scan_line = curr_max_scan_line;
+
+        if(font_data_changed || font_size_changed)
+        {
+            if(font_size_changed)
+            {
+                this.gfx_width = this.txt_width * this.font_width;
+                this.gfx_height = this.txt_height * this.font_height;
+                this.rebuild_image_data();
+            }
+            this.font_bitmap = this.rebuild_font_bitmap(width_9px, width_double);
+        }
+        this.mark_dirty();
+    }
+
+    // apply changes to cursor position
+    if(this.cursor_pos_dirty)
+    {
+        this.cursor_pos_dirty = false;
+        this.cursor_row_latch = Math.min(this.cursor_row_latch, this.txt_height-1);
+        this.cursor_col_latch = Math.min(this.cursor_col_latch, this.txt_width-1);
+        if(this.cursor_row !== this.cursor_row_latch || this.cursor_col !== this.cursor_col_latch)
+        {
+            this.txt_row_dirty[this.cursor_row] = this.txt_row_dirty[this.cursor_row_latch] = this.txt_dirty = 1;
+            this.cursor_row = this.cursor_row_latch;
+            this.cursor_col = this.cursor_col_latch;
+        }
+    }
+
+    // apply changes to cursor_enabled, cursor_top and cursor_bottom
+    if(this.cursor_attr_dirty)
+    {
+        this.cursor_attr_dirty = false;
+        if(this.cursor_enabled !== this.cursor_enabled_latch ||
+                this.cursor_top !== this.cursor_top_latch ||
+                this.cursor_bottom !== this.cursor_bottom_latch)
+        {
+            this.cursor_enabled = this.cursor_enabled_latch;
+            this.cursor_top = this.cursor_top_latch;
+            this.cursor_bottom = this.cursor_bottom_latch;
+            this.txt_row_dirty[this.cursor_row] = this.txt_dirty = 1;
+        }
+    }
+
+    // toggle cursor and blinking character visibility at a frequency of ~3.75hz (every 16th frame at 60fps)
+    // TODO: make framerate independant
+    //if(this.frame_count % 16 === 0)
+    //{
+    //    this.blink_visible = ! this.blink_visible;
+    //    if(this.font_blink_enabled)
+    //    {
+    //        this.mark_blinking_rows_dirty();
+    //    }
+    //    if(this.cursor_enabled)
+    //    {
+    //        this.txt_row_dirty[this.cursor_row] = this.txt_dirty = 1;
+    //    }
+    //}
+
+    // render changed rows
+    if(this.txt_dirty)
+    {
+        this.render_dirty_rows();
+        this.txt_dirty = 0;
+        this.txt_row_dirty.fill(0);
+    }
+
+    return this.image_data;
+};

From a9a538fe899fc8f372bf93ab16793c20ac327436 Mon Sep 17 00:00:00 2001
From: SuperMaxusa <41739128+SuperMaxusa@users.noreply.github.com>
Date: Fri, 27 Sep 2024 00:10:00 +0300
Subject: [PATCH 23/23] ci: set 1 hour timeout for "Build and test" job

---
 .github/workflows/ci.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c2ea9e7988..20d02d3656 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,6 +18,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     name: Build and test
+    timeout-minutes: 60
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4