diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2b66235..e72f99c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-2019, ubuntu-22.04, macos-13]
+        os: [windows-2019, windows-2022, ubuntu-22.04, ubuntu-24.04, macos-13]
         python-version: ['3.10', '3.11', '3.12']
     name: ${{ matrix.os }} / ${{ matrix.python-version }}
     runs-on: ${{ matrix.os }}
@@ -27,9 +27,9 @@ jobs:
       windows-2019-3-10: ${{ join(steps.*.outputs.windows-2019-3-10,'') }}
       windows-2019-3-11: ${{ join(steps.*.outputs.windows-2019-3-11,'') }}
       windows-2019-3-12: ${{ join(steps.*.outputs.windows-2019-3-12,'') }}
-      ubuntu-22.04-3-10: ${{ join(steps.*.outputs.ubuntu-22.04-3-10,'') }}
-      ubuntu-22.04-3-11: ${{ join(steps.*.outputs.ubuntu-22.04-3-11,'') }}
-      ubuntu-22.04-3-12: ${{ join(steps.*.outputs.ubuntu-22.04-3-12,'') }}
+      ubuntu-22-04-3-10: ${{ join(steps.*.outputs.ubuntu-22-04-3-10,'') }}
+      ubuntu-22-04-3-11: ${{ join(steps.*.outputs.ubuntu-22-04-3-11,'') }}
+      ubuntu-22-04-3-12: ${{ join(steps.*.outputs.ubuntu-22-04-3-12,'') }}
       macos-13-3-10: ${{ join(steps.*.outputs.macos-13-3-10,'') }}
       macos-13-3-11: ${{ join(steps.*.outputs.macos-13-3-11,'') }}
       macos-13-3-12: ${{ join(steps.*.outputs.macos-13-3-12,'') }}
@@ -47,62 +47,17 @@ jobs:
         version: 'latest'
 
     - name: "Install Pre-requisite (Linux)"
-      if: matrix.os == 'ubuntu-22.04'
+      if: startsWith(matrix.os, 'ubuntu')
       shell: bash
       run: |
         sudo apt update
-        sudo apt upgrade -y
-        sudo apt install -y build-essential libegl1 libgl1-mesa-glx
-
-    # - name: "Install Pre-requisite (macOS)"
-    #   if: matrix.os == 'macos-13'
-    #   run: |
-    #     env
-
-    # - name: "Install Pre-requisite (Windows)"
-    #   if: matrix.os == 'windows-2019'
-    #   shell: pwsh
-    #   run: |
-    #     env
+        sudo apt install -y build-essential libegl1
 
     - run: rye fmt
     - run: rye lint
     - run: rye test
     - run: rye build --wheel --out ./build
 
-
-    # - name: Build artifact
-    #   shell: bash
-    #   run: |
-    #     mkdir build
-    #     mkdir build/bin
-    #     python --version
-    #     python -m pip --version
-    #     python -m pip install --upgrade pip setuptools wheel
-    #     python -m pip install --user --upgrade .[all]
-
-    # - name: "Post build Cemu (Windows)"
-    #   if: matrix.os == 'windows-2019'
-    #   shell: pwsh
-    #   run: |
-    #     Copy-Item $env:APPDATA\Python\Python*\Scripts\cemu.exe build\bin\
-
-    # - name: "Post build Cemu (Linux)"
-    #   if: matrix.os == 'ubuntu-22.04'
-    #   shell: bash
-    #   run: |
-    #     cp -v ~/.local/bin/cemu build/bin/
-
-    # - name: "Post build Cemu (macOS)"
-    #   if: matrix.os == 'macos-13'
-    #   shell: bash
-    #   run: |
-    #     cp -v ~/.local/bin/cemu build/bin/ || cp -v /Users/runner/Library/Python/${{ matrix.python-version }}/bin/cemu build/bin/
-
-    # - name: "Run tests"
-    #   run: |
-    #     python -m pytest tests/
-
     - name: Publish artifact
       id: publish_artifact
       uses: actions/upload-artifact@v4
@@ -112,35 +67,39 @@ jobs:
 
     - name: Populate the successful output (Windows)
       id: output_success_windows
-      if: ${{ matrix.os == 'windows-2019' &&  success() }}
+      if: ${{ startsWith(matrix.os, 'windows') &&  success() }}
       shell: pwsh
       run: |
+        $osVersion = "${{ matrix.os }}" -replace "\.", "-"
         $pyVersion = "${{ matrix.python-version }}" -replace "\.", "-"
-        echo "${{ matrix.os }}-$pyVersion=✅ ${{ matrix.os }} ${{ matrix.python-version }}" | Out-File -FilePath $env:GITHUB_OUTPUT -Encoding utf8 -Append
+        echo "${osVersion}-$pyVersion=✅ ${{ matrix.os }} ${{ matrix.python-version }}" | Out-File -FilePath $env:GITHUB_OUTPUT -Encoding utf8 -Append
 
     - name: Populate the successful output (Other)
       id: output_success_other
-      if: ${{matrix.os != 'windows-2019' && success() }}
+      if: ${{startsWith(matrix.os, 'windows') == false && success() }}
       shell: bash
       run: |
+        osVersion="$(echo -n ${{ matrix.os }} | tr . -)"
         pyVersion="$(echo -n ${{ matrix.python-version }} | tr . -)"
-        echo "${{ matrix.os }}-${pyVersion}=✅ ${{ matrix.os }} ${{ matrix.python-version }}" >> $GITHUB_OUTPUT
+        echo "${osVersion}-${pyVersion}=✅ ${{ matrix.os }} ${{ matrix.python-version }}" >> $GITHUB_OUTPUT
 
     - name: Populate the failure output (Windows)
       id: output_failure_windows
-      if: ${{matrix.os == 'windows-2019' && failure() }}
+      if: ${{startsWith(matrix.os, 'windows') && failure() }}
       shell: pwsh
       run: |
+        $osVersion = "${{ matrix.os }}" -replace "\.", "-"
         $pyVersion = "${{ matrix.python-version }}" -replace "\.", "-"
-        echo "${{ matrix.os }}-${pyVersion}=❌ ${{ matrix.os }} ${{ matrix.python-version }}" | Out-File -FilePath $env:GITHUB_OUTPUT -Encoding utf8 -Append
+        echo "${osVersion}-${pyVersion}=❌ ${{ matrix.os }} ${{ matrix.python-version }}" | Out-File -FilePath $env:GITHUB_OUTPUT -Encoding utf8 -Append
 
     - name: Populate the failure output (Other)
       id: output_failure_other
-      if: ${{matrix.os != 'windows-2019' && failure() }}
+      if: ${{startsWith(matrix.os, 'windows') && failure() }}
       shell: bash
       run: |
+        osVersion="$(echo -n ${{ matrix.os }} | tr . -)"
         pyVersion="$(echo -n ${{ matrix.python-version }} | tr . -)"
-        echo "${{ matrix.os }}-$pyVersion=❌ ${{ matrix.os }} ${{ matrix.python-version }}" >> $GITHUB_OUTPUT
+        echo "${osVersion}-$pyVersion=❌ ${{ matrix.os }} ${{ matrix.python-version }}" >> $GITHUB_OUTPUT
 
   notify:
     env:
@@ -167,9 +126,9 @@ jobs:
           ${{ needs.build.outputs.windows-2019-3-10 }}
           ${{ needs.build.outputs.windows-2019-3-11 }}
           ${{ needs.build.outputs.windows-2019-3-12 }}
-          ${{ needs.build.outputs.ubuntu-22.04-3-10 }}
-          ${{ needs.build.outputs.ubuntu-22.04-3-11 }}
-          ${{ needs.build.outputs.ubuntu-22.04-3-12 }}
+          ${{ needs.build.outputs.ubuntu-22-04-3-10 }}
+          ${{ needs.build.outputs.ubuntu-22-04-3-11 }}
+          ${{ needs.build.outputs.ubuntu-22-04-3-12 }}
           ${{ needs.build.outputs.macos-13-3-10 }}
           ${{ needs.build.outputs.macos-13-3-11 }}
           ${{ needs.build.outputs.macos-13-3-12 }}
diff --git a/src/cemu/__main__.py b/src/cemu/__main__.py
index c8cf38b..f257840 100644
--- a/src/cemu/__main__.py
+++ b/src/cemu/__main__.py
@@ -20,9 +20,7 @@ def setup_remote_debug(port: int = cemu.const.DEBUG_DEBUGPY_PORT):
 
 
 def main(argv: list[str]):
-    parser = argparse.ArgumentParser(
-                        prog=cemu.const.PROGNAME,
-                        description=cemu.const.DESCRIPTION)
+    parser = argparse.ArgumentParser(prog=cemu.const.PROGNAME, description=cemu.const.DESCRIPTION)
     parser.add_argument("filename")
     parser.add_argument("--debug", action="store_true")
     parser.add_argument("--attach", action="store_true")
@@ -46,6 +44,7 @@ def main(argv: list[str]):
 
 if __name__ == "__main__":
     import sys
+
     path = pathlib.Path(__file__).absolute().parent.parent
     sys.path.append(str(path))
     main(sys.argv)
diff --git a/src/cemu/arch/__init__.py b/src/cemu/arch/__init__.py
index fdf0db5..216c2f9 100644
--- a/src/cemu/arch/__init__.py
+++ b/src/cemu/arch/__init__.py
@@ -1,19 +1,24 @@
+from dataclasses import dataclass
 import enum
 import importlib
+import pathlib
 from typing import Optional, TYPE_CHECKING
 
 import capstone
 import keystone
 import unicorn
 
+import cemu.errors
 from cemu.const import SYSCALLS_PATH
-from ..ui.utils import popup, PopupType
+from cemu.log import dbg, error
+from cemu.utils import DISASSEMBLY_DEFAULT_BASE_ADDRESS
+
 
 if TYPE_CHECKING:
     import cemu.core
 
 
-class Endianness(enum.Enum):
+class Endianness(enum.IntEnum):
     LITTLE_ENDIAN = 1
     BIG_ENDIAN = 2
 
@@ -27,7 +32,7 @@ def __int__(self) -> int:
         return self.value
 
 
-class Syntax(enum.Enum):
+class Syntax(enum.IntEnum):
     INTEL = 1
     ATT = 2
 
@@ -71,26 +76,29 @@ def syscalls(self):
         if not self.__context:
             import cemu.core
 
+            assert cemu.core.context
             self.__context = cemu.core.context
             assert isinstance(self.__context, cemu.core.GlobalContext)
 
         if not self.__syscalls:
-            syscall_dir = SYSCALLS_PATH / str(self.__context.os)
+            syscall_dir = SYSCALLS_PATH / str(self.__context.os).lower()
 
             try:
                 fpath = syscall_dir / (self.syscall_filename + ".csv")
             except ValueError as e:
-                popup(str(e), PopupType.Error, "No Syscall File Error")
+                error(f"No Syscall File Error: {e}")
                 return {}
 
             self.__syscalls = {}
-            if fpath.exists():
-                with fpath.open("r") as fd:
-                    for row in fd.readlines():
-                        row = [x.strip() for x in row.strip().split(",")]
-                        syscall_number = int(row[0])
-                        syscall_name = row[1].lower()
-                        self.__syscalls[syscall_name] = self.syscall_base + syscall_number
+            if not fpath.exists():
+                raise FileNotFoundError(fpath)
+
+            with fpath.open("r") as fd:
+                for row in fd.readlines():
+                    row = [x.strip() for x in row.strip().split(",")]
+                    syscall_number = int(row[0])
+                    syscall_name = row[1].lower()
+                    self.__syscalls[syscall_name] = self.syscall_base + syscall_number
 
         return self.__syscalls
 
@@ -264,3 +272,118 @@ def is_sparc64(a: Architecture):
 
 def is_ppc(a: Architecture):
     return isinstance(a, PowerPC)
+
+
+def format_address(addr: int, arch: Optional[Architecture] = None) -> str:
+    """Format an address to string, aligned to the given architecture
+
+    Args:
+        addr (int): _description_
+        arch (Optional[Architecture], optional): _description_. Defaults to None.
+
+    Raises:
+        ValueError: _description_
+
+    Returns:
+        str: _description_
+    """
+    if arch is None:
+        import cemu.core
+
+        if not cemu.core.context:
+            ptrsize = 8
+        else:
+            ptrsize = cemu.core.context.architecture.ptrsize
+    else:
+        ptrsize = arch.ptrsize
+
+    match ptrsize:
+        case 2:
+            return f"{addr:#04x}"
+        case 4:
+            return f"{addr:#08x}"
+        case 8:
+            return f"{addr:#016x}"
+        case _:
+            raise ValueError(f"Invalid pointer size value of {ptrsize}")
+
+
+@dataclass
+class Instruction:
+    address: int
+    mnemonic: str
+    operands: str
+    bytes: bytes
+
+    @property
+    def size(self):
+        return len(self.bytes)
+
+    @property
+    def end(self) -> int:
+        return self.address + self.size
+
+    def __str__(self):
+        return f'Instruction({self.address:#x}, "{self.mnemonic} {self.operands}")'
+
+
+def disassemble(raw_data: bytes, count: int = -1, base: int = DISASSEMBLY_DEFAULT_BASE_ADDRESS) -> list[Instruction]:
+    """Disassemble the code given as raw data, with the given architecture.
+
+    Args:
+        raw_data (bytes): the raw byte code to disassemble
+        arch (Architecture): the architecture to use for disassembling
+        count (int, optional): the maximum number of instruction to disassemble. Defaults to -1.
+        base (int, optional): the disassembled code base address. Defaults to DISASSEMBLY_DEFAULT_BASE_ADDRESS
+
+    Returns:
+        str: the text representation of the disassembled code
+    """
+    assert cemu.core.context
+    arch = cemu.core.context.architecture
+    insns: list[Instruction] = []
+    for idx, ins in enumerate(arch.cs.disasm(raw_data, base)):
+        insn = Instruction(ins.address, ins.mnemonic, ins.op_str, ins.bytes)
+        insns.append(insn)
+        if idx == count:
+            break
+
+    dbg(f"{insns=}")
+    return insns
+
+
+def disassemble_file(fpath: pathlib.Path) -> list[Instruction]:
+    return disassemble(fpath.read_bytes())
+
+
+def assemble(code: str, base_address: int = DISASSEMBLY_DEFAULT_BASE_ADDRESS) -> list[Instruction]:
+    """
+    Helper function to assemble code receive in parameter `asm_code` using Keystone.
+
+    @param code : assembly code in bytes (multiple instructions must be separated by ';')
+    @param base_address : (opt) the base address to use
+
+    @return a list of Instruction
+    """
+    assert cemu.core.context
+    arch = cemu.core.context.architecture
+
+    #
+    # Compile the entire given code
+    #
+    bytecode, assembled_insn_count = arch.ks.asm(code, as_bytes=True, addr=base_address)
+    if not bytecode or assembled_insn_count == 0:
+        raise cemu.errors.AssemblyException("Not instruction compiled")
+
+    assert isinstance(bytecode, bytes)
+
+    #
+    # Decompile it and return the stuff
+    #
+    insns = disassemble(bytecode, base=base_address)
+    dbg(f"{insns=}")
+    return insns
+
+
+def assemble_file(fpath: pathlib.Path) -> list[Instruction]:
+    return assemble(fpath.read_text())
diff --git a/src/cemu/cli/repl.py b/src/cemu/cli/repl.py
index df8aadd..04d6010 100644
--- a/src/cemu/cli/repl.py
+++ b/src/cemu/cli/repl.py
@@ -26,7 +26,9 @@
 
 @bindings.add("c-c")
 def _(event):
+    assert cemu.core.context
     if cemu.core.context.emulator.is_running:
+        assert cemu.core.context
         cemu.core.context.emulator.set(EmulatorState.FINISHED)
     pass
 
@@ -35,6 +37,8 @@ class CEmuRepl:
     def __init__(self, args):
         super(CEmuRepl, self).__init__()
         assert cemu.core.context
+        assert cemu.core.context
+        assert cemu.core.context
         assert isinstance(cemu.core.context, cemu.core.GlobalContext)
 
         self.history_filepath = pathlib.Path().home() / ".cemu_history"
@@ -42,9 +46,11 @@ def __init__(self, args):
         self.keep_running = False
         self.prompt = "(cemu)> "
         self.__background_emulator_thread = EmulationRunner()
+        assert cemu.core.context
         cemu.core.context.emulator.set_threaded_runner(self.__background_emulator_thread)
 
         # register the callbacks for the emulator
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         # emu.add_state_change_cb(
         #     EmulatorState.NOT_RUNNING, self.update_layout_not_running
@@ -65,6 +71,7 @@ def __init__(self, args):
 
     def run_forever(self):
         self.keep_running = True
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         while self.keep_running:
             #
@@ -163,8 +170,10 @@ def run_forever(self):
                 case "arch":
                     match args[0]:
                         case "get":
+                            assert cemu.core.context
                             print(f"Current architecture {cemu.core.context.architecture}")
                         case "set":
+                            assert cemu.core.context
                             cemu.core.context.architecture = cemu.arch.Architectures.find(args[1])
 
                 case "regs":
@@ -253,6 +262,7 @@ def run_forever(self):
         return
 
     def bottom_toolbar(self) -> str:
+        assert cemu.core.context
         return f"{str(cemu.core.context.emulator)} [{str(cemu.core.context.architecture)}]"
 
 
@@ -263,6 +273,7 @@ def run(self):
         """
         Runs the emulation
         """
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         if not emu.vm:
             error("VM is not ready")
diff --git a/src/cemu/core.py b/src/cemu/core.py
index 1e2a7d4..359f5f4 100644
--- a/src/cemu/core.py
+++ b/src/cemu/core.py
@@ -76,7 +76,7 @@ def root(self, root: cemu.ui.main.CEmuWindow):
 #
 # The global application context. This **must** defined for cemu to operate
 #
-context: Union[GlobalContext, GlobalGuiContext]
+context: Optional[Union[GlobalContext, GlobalGuiContext]] = None
 
 
 def CemuGui() -> None:
@@ -93,8 +93,10 @@ def CemuGui() -> None:
     cemu.log.dbg("Creating GUI context")
     context = GlobalGuiContext()
 
+    default_style_sheet = cemu.const.DEFAULT_STYLE_PATH.read_text()
+
     app = QApplication(sys.argv)
-    app.setStyleSheet(cemu.const.DEFAULT_STYLE_PATH.open().read())
+    app.setStyleSheet(default_style_sheet)
     app.setWindowIcon(QIcon(str(cemu.const.ICON_PATH.absolute())))
     context.root = cemu.ui.main.CEmuWindow(app)
     sys.exit(app.exec())
diff --git a/src/cemu/emulator.py b/src/cemu/emulator.py
index 29f0c4e..6e71af7 100644
--- a/src/cemu/emulator.py
+++ b/src/cemu/emulator.py
@@ -1,7 +1,7 @@
 import collections
 from enum import IntEnum, unique
 from multiprocessing import Lock
-from typing import Any, Callable, Optional
+from typing import Any, Callable, Optional, TYPE_CHECKING
 
 import unicorn
 
@@ -21,6 +21,10 @@
 from .ui.utils import popup, PopupType
 
 
+if TYPE_CHECKING:
+    import cemu.arch
+
+
 @unique
 class EmulatorState(IntEnum):
     INVALID = 0
@@ -59,6 +63,7 @@ def __getitem__(self, key: str) -> int:
         Returns:
             int: the register value
         """
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         if emu.state in (EmulatorState.RUNNING, EmulatorState.IDLE, EmulatorState.FINISHED) and key in self.data.keys():
             val = emu.get_register_value(key)
@@ -98,6 +103,7 @@ def reset(self):
         self.vm = None
         self.code = b""
         self.sections = MEMORY_MAP_DEFAULT_LAYOUT[:]
+        assert cemu.core.context
         self.registers = EmulationRegisters({name: 0 for name in cemu.core.context.architecture.registers})
         self.start_addr = 0
         self.set(EmulatorState.NOT_RUNNING)
@@ -116,6 +122,7 @@ def get_register_value(self, regname: str) -> Optional[int]:
         if not self.vm:
             return None
 
+        assert cemu.core.context
         arch = cemu.core.context.architecture
         ur = arch.uc_register(regname)
         val = self.vm.reg_read(ur)
@@ -130,14 +137,18 @@ def pc(self) -> int:
         """
         Returns the current value of $pc
         """
+        assert cemu.core.context
         # return self.get_register_value(cemu.core.context.architecture.pc)
+        assert cemu.core.context
         return self.registers[cemu.core.context.architecture.pc]
 
     def sp(self) -> int:
         """
         Returns the current value of $sp
         """
+        assert cemu.core.context
         # return self.get_register_value(cemu.core.context.architecture.sp)
+        assert cemu.core.context
         return self.registers[cemu.core.context.architecture.sp]
 
     def setup(self) -> None:
@@ -152,6 +163,7 @@ def setup(self) -> None:
 
         info("Setting up emulation environment...")
 
+        assert cemu.core.context
         arch = cemu.core.context.architecture
         self.vm = arch.uc
         self.vm.hook_add(unicorn.UC_HOOK_BLOCK, self.hook_block)
@@ -159,6 +171,7 @@ def setup(self) -> None:
         self.vm.hook_add(unicorn.UC_HOOK_INTR, self.hook_interrupt)  # type: ignore
         self.vm.hook_add(unicorn.UC_HOOK_MEM_WRITE, self.hook_mem_access)
         self.vm.hook_add(unicorn.UC_HOOK_MEM_READ, self.hook_mem_access)
+        assert cemu.core.context
         if is_x86(cemu.core.context.architecture):
             self.vm.hook_add(
                 unicorn.UC_HOOK_INSN,
@@ -217,6 +230,7 @@ def __populate_vm_registers(self) -> bool:
         if not self.vm:
             return False
 
+        assert cemu.core.context
         arch = cemu.core.context.architecture
 
         #
@@ -296,6 +310,7 @@ def __refresh_registers_from_vm(self) -> bool:
         if not self.vm or not self.is_running:
             return False
 
+        assert cemu.core.context
         arch = cemu.core.context.architecture
         for regname in self.registers.keys():
             value = self.vm.reg_read(arch.uc_register(regname))
@@ -310,10 +325,11 @@ def __generate_text_bytecode(self) -> bool:
         Returns:
             bool True if all went well, False otherwise.
         """
+        assert cemu.core.context
         dbg(f"[vm::setup] Generating assembly code for {cemu.core.context.architecture.name}")
 
         try:
-            insns = cemu.utils.assemble(self.codelines, base_address=self.start_addr)
+            insns = cemu.arch.assemble(self.codelines, base_address=self.start_addr)
             if len(insns) == 0:
                 raise Exception("no instruction")
         except Exception as e:
@@ -356,11 +372,11 @@ def __populate_text_section(self) -> bool:
         self.vm.mem_write(text_section.address, self.code)
         return True
 
-    def next_instruction(self, code: bytes, addr: int) -> Optional[cemu.utils.Instruction]:
+    def next_instruction(self, code: bytes, addr: int) -> Optional[cemu.arch.Instruction]:
         """
         Returns a string disassembly of the first instruction from `code`.
         """
-        for insn in cemu.utils.disassemble(code, 1, addr):
+        for insn in cemu.arch.disassemble(code, 1, addr):
             return insn
 
         return None
@@ -376,7 +392,8 @@ def hook_code(self, emu: unicorn.Uc, address: int, size: int, user_data: Any) ->
             return False
 
         code = self.vm.mem_read(address, size)
-        insn: cemu.utils.Instruction = self.next_instruction(code, address)
+        insn = self.next_instruction(code, address)
+        assert isinstance(insn, cemu.arch.Instruction)
 
         if self.use_step_mode:
             dbg(f"[vm::runtime] Stepping @ {insn}")
diff --git a/src/cemu/examples/aarch64_execve_bin_sh.asm b/src/cemu/examples/aarch64_sys_exec_bin_sh.asm
similarity index 100%
rename from src/cemu/examples/aarch64_execve_bin_sh.asm
rename to src/cemu/examples/aarch64_sys_exec_bin_sh.asm
diff --git a/src/cemu/examples/arm_sys_exec_bin_sh.asm b/src/cemu/examples/arm_sys_exec_bin_sh.asm
index 3aedc76..4eda262 100644
--- a/src/cemu/examples/arm_sys_exec_bin_sh.asm
+++ b/src/cemu/examples/arm_sys_exec_bin_sh.asm
@@ -1,11 +1,11 @@
-#
-# ARM sys_exec("/bin/sh") shellcode
-#
-# @_hugsy_
-#
-ldr r0, ="nib/"
+;;;
+;;; ARM sys_exec("/bin/sh") shellcode
+;;;
+;;; @_hugsy_
+;;;
+ldr r0, =0x2f62696e
 str r0, [sp]
-ldr r0, ="hs//"
+ldr r0, =0x2f2f7368
 str r0, [sp, 4]
 mov r0, sp
 mov r1, 0
diff --git a/src/cemu/examples/mips_sys_exec_bin_sh.asm b/src/cemu/examples/mips_sys_exec_bin_sh.asm
index 13e7c1d..338dc33 100644
--- a/src/cemu/examples/mips_sys_exec_bin_sh.asm
+++ b/src/cemu/examples/mips_sys_exec_bin_sh.asm
@@ -3,9 +3,9 @@
 ;;;
 ;;; @_hugsy_
 ;;;
-li $v0, "nib/"
+li $v0, 0x2f62696e
 sw $v0, 0($sp)
-li $v0, "hs//"
+li $v0, 0x2f2f7368
 sw $v0, 4($sp)
 li $v0, __NR_SYS_execve
 move $a0, $sp
diff --git a/src/cemu/examples/sparc64_sys_exec_bin_sh.asm b/src/cemu/examples/sparc64_sys_exec_bin_sh.asm
index 3424e54..bd82cf2 100644
--- a/src/cemu/examples/sparc64_sys_exec_bin_sh.asm
+++ b/src/cemu/examples/sparc64_sys_exec_bin_sh.asm
@@ -2,12 +2,12 @@
 ;;;
 ;;; @_hugsy_
 ;;;
-    mov  0x6e69622f, %g1
-    st %g1, [ %sp ]
-    mov  0x0068732f, %g1
-    st %g1, [ %sp + 4 ]
-    mov  %g1, %o0
-    clr  %o1
-    clr  %o2
-    mov  11, %g1
-    t 0x6d
+mov  0x6e69622f, %g1
+st %g1, [ %sp ]
+mov  0x0068732f, %g1
+st %g1, [ %sp + 4 ]
+mov  %g1, %o0
+clr  %o1
+clr  %o2
+mov  11, %g1
+t 0x6d
diff --git a/src/cemu/examples/x86_32_sys_exec_bin_sh.asm b/src/cemu/examples/x86_32_sys_exec_bin_sh.asm
index f02415c..079264a 100644
--- a/src/cemu/examples/x86_32_sys_exec_bin_sh.asm
+++ b/src/cemu/examples/x86_32_sys_exec_bin_sh.asm
@@ -9,8 +9,8 @@
 ;;; eax = sys_execve
 mov eax, __NR_SYS_execve
 ;;; write /bin/sh @esp
-mov dword ptr [esp], "nib/"
-mov dword ptr [esp+4], "hs//"
+mov dword ptr [esp], 0x2f62696e
+mov dword ptr [esp+4], 0x2f2f7368
 ;;; ebx = @/bin/sh
 mov ebx, esp
 ;;; nullify the other args
diff --git a/src/cemu/examples/x86_64_sys_exec_bin_sh.asm b/src/cemu/examples/x86_64_sys_exec_bin_sh.asm
index 76ac8e6..314f9e8 100644
--- a/src/cemu/examples/x86_64_sys_exec_bin_sh.asm
+++ b/src/cemu/examples/x86_64_sys_exec_bin_sh.asm
@@ -10,7 +10,7 @@
 ;;; rax = sys_execve
 mov rax, __NR_SYS_execve
 ;;; write /bin/sh @rsp
-mov rsi, "hs//nib/" # or 0x68732f2f6e69622f
+mov rsi, 0x68732f2f6e69622f
 mov [rsp], rsi
 ;;; rdi = @/bin/sh
 mov rdi, rsp
@@ -18,4 +18,4 @@ mov rdi, rsp
 xor rsi, rsi
 xor rdx, rdx
 ;;; trigger syscall
-syscall
\ No newline at end of file
+syscall
diff --git a/src/cemu/exports.py b/src/cemu/exports.py
index f820156..079095b 100644
--- a/src/cemu/exports.py
+++ b/src/cemu/exports.py
@@ -6,7 +6,7 @@
 
 from .arch import Architecture, is_x86_32, is_x86_64
 from .memory import MemoryPermission, MemorySection
-from .utils import generate_random_string
+import cemu.utils
 
 
 def parse_as_lief_pe_permission(perm: MemoryPermission, extra: Any = None) -> int:
@@ -42,10 +42,10 @@ def build_pe_executable(text: bytes, memory_layout: List[MemorySection], arch: A
     is_x64 = is_x86_64(arch)
 
     if is_x64:
-        basename = "cemu-pe-amd64-{:s}".format(generate_random_string(5))
+        basename = "cemu-pe-amd64-{:s}".format(cemu.utils.generate_random_string(5))
         pe = PE.Binary(basename, PE.PE_TYPE.PE32_PLUS)
     else:
-        basename = "cemu-pe-i386-{:s}".format(generate_random_string(5))
+        basename = "cemu-pe-i386-{:s}".format(cemu.utils.generate_random_string(5))
         pe = PE.Binary(basename, PE.PE_TYPE.PE32)
 
     # adding sections
diff --git a/src/cemu/memory.py b/src/cemu/memory.py
index de04f6c..1d9ab3d 100644
--- a/src/cemu/memory.py
+++ b/src/cemu/memory.py
@@ -215,7 +215,7 @@ def content(self) -> Optional[bytes]:
         if not self.file_source:
             return None
 
-        data = self.file_source.open("rb").read()
+        data = self.file_source.read_bytes()
         if len(data) > self.size:
             raise AttributeError("Insufficient space")
         return data
diff --git a/src/cemu/plugins/__init__.py b/src/cemu/plugins/__init__.py
index 03c95fb..671ab79 100644
--- a/src/cemu/plugins/__init__.py
+++ b/src/cemu/plugins/__init__.py
@@ -26,7 +26,9 @@ def __str__(self):
 
     @property
     def rootWindow(self) -> CEmuWindow:
+        assert cemu.core.context
         assert isinstance(cemu.core.context, cemu.core.GlobalGuiContext)
+        assert cemu.core.context
         return cemu.core.context.root
 
 
diff --git a/src/cemu/plugins/pyconsole/console.py b/src/cemu/plugins/pyconsole/console.py
index 08e86ee..50ecaf6 100644
--- a/src/cemu/plugins/pyconsole/console.py
+++ b/src/cemu/plugins/pyconsole/console.py
@@ -202,6 +202,7 @@ def keyPressEvent(self, event):
 
     @property
     def emu(self) -> cemu.emulator.Emulator:
+        assert cemu.core.context
         return cemu.core.context.emulator
 
     @property
@@ -210,4 +211,5 @@ def vm(self):
 
     @property
     def arch(self):
+        assert cemu.core.context
         return cemu.core.context.architecture
diff --git a/src/cemu/settings.py b/src/cemu/settings.py
index 931f77d..6270609 100644
--- a/src/cemu/settings.py
+++ b/src/cemu/settings.py
@@ -76,8 +76,7 @@ def __create_default_config_file(self) -> None:
         """
         Deploy a new config file as ~/.cemu.ini
         """
-        with self.__config_filename.open("w") as cfg:
-            cfg.write(cemu.const.TEMPLATE_CONFIG.open().read())
+        self.__config_filename.write_text(cemu.const.TEMPLATE_CONFIG.read_text())
         return
 
     def __contains__(self, key: str) -> bool:
diff --git a/src/cemu/shortcuts.py b/src/cemu/shortcuts.py
index e607fa6..a4ffd56 100644
--- a/src/cemu/shortcuts.py
+++ b/src/cemu/shortcuts.py
@@ -44,6 +44,7 @@ def load(self) -> bool:
         Load the shortcuts dict from either the config file if the value exists, or
         the defaults
         """
+        assert cemu.core.context
         settings = cemu.core.context.settings
         for key in self._defaults:
             default_shortcut, description = self._defaults[key]
diff --git a/src/cemu/ui/codeeditor.py b/src/cemu/ui/codeeditor.py
index 8ce7904..078eba8 100644
--- a/src/cemu/ui/codeeditor.py
+++ b/src/cemu/ui/codeeditor.py
@@ -29,7 +29,7 @@
 if typing.TYPE_CHECKING:
     from cemu.ui.main import CEmuWindow
 
-from ..utils import assemble
+from ..arch import assemble
 from .highlighter import Highlighter
 from .utils import get_cursor_position
 
@@ -160,6 +160,7 @@ def __init__(self, parent, *args, **kwargs):
         self.setWidget(widget)
 
     def onUpdateText(self):
+        assert cemu.core.context
         cemu.core.context.emulator.codelines = self.getCleanContent()
 
     def onCursorPositionChanged(self):
@@ -189,6 +190,7 @@ def remove_comments(lines: list[str]) -> list[str]:
 
         def parse_syscalls(lines: list[str]) -> list[str]:
             parsed = []
+            assert cemu.core.context
             syscalls = cemu.core.context.architecture.syscalls
             syscall_names = syscalls.keys()
             for line in lines:
diff --git a/src/cemu/ui/command.py b/src/cemu/ui/command.py
index 8df42e4..15a8a8a 100644
--- a/src/cemu/ui/command.py
+++ b/src/cemu/ui/command.py
@@ -6,7 +6,7 @@
 from PyQt6.QtWidgets import QDockWidget, QHBoxLayout, QPushButton, QWidget
 
 import cemu.core
-from cemu import utils
+import cemu.arch
 from cemu.emulator import Emulator, EmulatorState
 from cemu.log import dbg, info
 from cemu.ui.utils import PopupType, popup
@@ -58,6 +58,7 @@ def __init__(self, parent: CEmuWindow, *args, **kwargs):
         #
         # Emulator state callback
         #
+        assert cemu.core.context
         self.emulator: Emulator = cemu.core.context.emulator
 
         self.emulator.add_state_change_cb(EmulatorState.NOT_RUNNING, self.onNotRunningUpdateCommandButtons)
@@ -113,7 +114,7 @@ def onClickCheckCode(self) -> None:
             if not code:
                 raise ValueError("Empty code")
 
-            insns = utils.assemble(code)
+            insns = cemu.arch.assemble(code)
             title = "Success"
             msg = f"Your code is syntaxically valid, {len(insns)} instructions compiled"
             popup_style = PopupType.Information
diff --git a/src/cemu/ui/highlighter.py b/src/cemu/ui/highlighter.py
index 7aeef3e..4cce9de 100644
--- a/src/cemu/ui/highlighter.py
+++ b/src/cemu/ui/highlighter.py
@@ -68,7 +68,11 @@ def __init__(self, parent, mode):
     def highlightBlock(self, text):
         cb = self.currentBlock()
         pos = cb.position()
-        text = self.document().toPlainText() + "\n"
+        doc = self.document()
+        if not doc:
+            cemu.log.dbg("Missing doc")
+            return
+        text = doc.toPlainText() + "\n"
         highlight(text, self.lexer, self.formatter)
         for i in range(len(text)):
             try:
diff --git a/src/cemu/ui/main.py b/src/cemu/ui/main.py
index 9566a80..5f19341 100644
--- a/src/cemu/ui/main.py
+++ b/src/cemu/ui/main.py
@@ -20,6 +20,7 @@
 )
 
 import cemu.core
+import cemu.arch
 import cemu.exports
 import cemu.plugins
 import cemu.utils
@@ -53,7 +54,9 @@ class CEmuWindow(QMainWindow):
     def __init__(self, app: QApplication, *args, **kwargs):
         super(CEmuWindow, self).__init__()
         self.currentAction: Optional[QAction] = None
+        assert cemu.core.context
         assert cemu.core.context is not None
+        assert cemu.core.context
         assert isinstance(cemu.core.context, cemu.core.GlobalGuiContext)
 
         self.rootWindow: CEmuWindow = self
@@ -64,6 +67,7 @@ def __init__(self, app: QApplication, *args, **kwargs):
         # self.signals = {} Unused?
         self.current_file: Optional[pathlib.Path] = None
         self.__background_emulator_thread: EmulationRunner = EmulationRunner()
+        assert cemu.core.context
         cemu.core.context.emulator.set_threaded_runner(self.__background_emulator_thread)
 
         self.shortcuts: ShortcutManager = ShortcutManager()
@@ -100,6 +104,7 @@ def __init__(self, app: QApplication, *args, **kwargs):
         self.__app.aboutToQuit.connect(self.onAboutToQuit)
 
         # register the callbacks for the emulator
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         emu.add_state_change_cb(EmulatorState.NOT_RUNNING, self.update_layout_not_running)
         emu.add_state_change_cb(EmulatorState.RUNNING, self.update_layout_running)
@@ -107,6 +112,7 @@ def __init__(self, app: QApplication, *args, **kwargs):
         emu.add_state_change_cb(EmulatorState.FINISHED, self.update_layout_step_finished)
 
         # show everything
+        assert cemu.core.context
         start_in_full_screen = cemu.core.context.settings.getboolean("Global", "StartInFullScreen")
         if start_in_full_screen:
             self.showMaximized()
@@ -129,6 +135,7 @@ def __del__(self):
 
     def changeEvent(self, event):
         if event.type() == QEvent.Type.WindowStateChange:
+            assert cemu.core.context
             cemu.core.context.settings.set("Global", "StartInFullScreen", str(self.isMaximized()))
         super().changeEvent(event)
 
@@ -136,7 +143,9 @@ def onAboutToQuit(self):
         """
         Overriding the aboutToSignal handler
         """
+        assert cemu.core.context
         if cemu.core.context.settings.getboolean("Global", "SaveConfigOnExit"):
+            assert cemu.core.context
             cemu.core.context.settings.save()
             ok("Settings saved...")
         return
@@ -161,18 +170,23 @@ def LoadExtraPlugins(self) -> int:
         return nb_added
 
     def setMainWindowProperty(self) -> None:
+        assert cemu.core.context
         width = cemu.core.context.settings.getint("Global", "WindowWidth", 800)
+        assert cemu.core.context
         heigth = cemu.core.context.settings.getint("Global", "WindowHeight", 600)
         self.resize(width, heigth)
         self.refreshWindowTitle()
 
         # center the window
         frame_geometry = self.frameGeometry()
-        screen = self.screen().availableGeometry().center()
-        frame_geometry.moveCenter(screen)
+        screen = self.screen()
+        if screen:
+            p = screen.availableGeometry().center()
+            frame_geometry.moveCenter(p)
         self.move(frame_geometry.topLeft())
 
         # apply the style
+        assert cemu.core.context
         style = cemu.core.context.settings.get("Theme", "QtStyle", "Cleanlooks")
         self.__app.setStyle(style)
         return
@@ -205,10 +219,16 @@ def addMenuItem(
     def setMainWindowMenuBar(self):
         self.statusBar()
         menubar = self.menuBar()
+        if not menubar:
+            popup("No menubar found")
+            return
+
+        assert cemu.core.context
         maxRecentFiles = cemu.core.context.settings.getint("Global", "MaxRecentFiles")
 
         # Create "File" menu options
         fileMenu = menubar.addMenu("&File")
+        assert fileMenu
 
         # "Open File" submenu
         openAsmAction = self.addMenuItem(
@@ -327,11 +347,14 @@ def setMainWindowMenuBar(self):
 
         # Add Architecture menu bar
         archMenu = menubar.addMenu("&Architecture")
+        assert archMenu
         for abi in sorted(Architectures.keys()):
             archSubMenu = archMenu.addMenu(abi.upper())
+            assert archSubMenu
             for arch in Architectures[abi]:
                 label = f"{arch.name:s} / Endian: {str(arch.endianness)} / Syntax: {str(arch.syntax)}"
                 self.archActions[label] = QAction(QIcon(), label, self)
+                assert cemu.core.context
                 if arch == cemu.core.context.architecture:
                     self.archActions[label].setEnabled(False)
                     self.currentAction = self.archActions[label]
@@ -342,6 +365,7 @@ def setMainWindowMenuBar(self):
 
         # Add the View Window menu bar
         viewWindowsMenu = menubar.addMenu("&View")
+        assert viewWindowsMenu
         toggleFocusMode = self.addMenuItem(
             "Toggle Focus Mode",
             self.toggleFocusMode,
@@ -367,6 +391,7 @@ def setMainWindowMenuBar(self):
 
         # Add Help menu bar
         helpMenu = menubar.addMenu("&Help")
+        assert helpMenu
         shortcutAction = self.addMenuItem(
             "Shortcuts",
             self.showShortcutPopup,
@@ -434,7 +459,7 @@ def loadFile(self, fpath: pathlib.Path) -> None:
             KeyError: if the architecture from the file metadata is invalid
         """
         dbg(f"Trying to load '{fpath}'")
-        content = fpath.open().read()
+        content = fpath.read_text()
 
         try:
             res = cemu.utils.get_metadata_from_stream(content)
@@ -474,7 +499,7 @@ def loadCode(self, title, filter, run_disassembler):
 
         if run_disassembler:
             with tempfile.NamedTemporaryFile("w", suffix=".asm", delete=False) as fd:
-                disassembled_instructions = cemu.utils.disassemble_file(fpath)
+                disassembled_instructions = cemu.arch.disassemble_file(fpath)
                 fd.write(os.linesep.join([f"{insn.mnemonic}, {insn.operands}" for insn in disassembled_instructions]))
                 fpath = pathlib.Path(fd.name)
 
@@ -507,12 +532,12 @@ def saveCode(self, title, filter, run_assembler):
 
         if run_assembler:
             raw_assembly = self.get_codeview_content()
-            insns: list[cemu.utils.Instruction] = cemu.utils.assemble(raw_assembly)
+            insns: list["cemu.arch.Instruction"] = cemu.arch.assemble(raw_assembly)
             raw_bytecode = b"".join([insn.bytes for insn in insns])
-            fpath.open("wb").write(raw_bytecode)
+            fpath.write_bytes(raw_bytecode)
         else:
             raw_bytecode = self.get_codeview_content()
-            fpath.open("w").write(raw_bytecode)
+            fpath.write_text(raw_bytecode)
 
         ok(f"Saved as '{fpath}'")
         return
@@ -537,10 +562,10 @@ def saveCodeBin(self):
         return self.saveCode("Save Raw Binary Pane As", "Raw binary files (*.raw)", True)
 
     def saveAsCFile(self):
-        template = (TEMPLATE_PATH / "linux" / "template.c").open("r").read()
+        template = (TEMPLATE_PATH / "linux" / "template.c").read_text("r")
         output: list[str] = []
         lines = self.get_codeview_content().splitlines()
-        insns = cemu.utils.assemble(self.get_codeview_content())
+        insns = cemu.arch.assemble(self.get_codeview_content())
         for i, insn in enumerate(insns):
             hexa = ", ".join([f"{b:#02x}" for b in insn.bytes])
             line = f"/* {i:#08x} */   {hexa}   // {lines[i]}"
@@ -551,6 +576,7 @@ def saveAsCFile(self):
             return
 
         with picked_file_path.open("w") as fd:
+            assert cemu.core.context
             body = template % (
                 cemu.core.context.architecture.name,
                 len(insns),
@@ -562,17 +588,16 @@ def saveAsCFile(self):
 
     def saveAsAsmFile(self) -> None:
         """Write the content of the ASM pane to disk"""
-        template = (TEMPLATE_PATH / "linux" / "template.asm").open("r").read()
+        template = (TEMPLATE_PATH / "linux" / "template.asm").read_text()
         code = self.get_codeview_content()
 
         picked_file_path = self.pick_file("Save As Generated Assembly File", "Assembly files (*.asm *.s)")
         if picked_file_path is None:
             return
 
-        with picked_file_path.open("w") as fd:
-            body = template % (cemu.core.context.architecture.name, code)
-            fd.write(body)
-            ok(f"Saved as '{fd.name}'")
+        assert cemu.core.context
+        picked_file_path.write_text(template % (cemu.core.context.architecture.name, code))
+        ok(f"Saved as '{picked_file_path}'")
         return
 
     def generate_pe(self) -> None:
@@ -580,9 +605,10 @@ def generate_pe(self) -> None:
         memory_layout = self.get_memory_layout()
         code = self.get_codeview_content()
         try:
-            insns = cemu.utils.assemble(code)
+            insns = cemu.arch.assemble(code)
             if len(insns) > 0:
                 asm_code = b"".join([x.bytes for x in insns])
+                assert cemu.core.context
                 pe = cemu.exports.build_pe_executable(asm_code, memory_layout, cemu.core.context.architecture)
                 info(f"PE file written as '{pe}'")
         except Exception as e:
@@ -594,9 +620,10 @@ def generate_elf(self) -> None:
         memory_layout = self.get_memory_layout()
         code = self.get_codeview_content()
         try:
-            insns = cemu.utils.assemble(code)
+            insns = cemu.arch.assemble(code)
             if len(insns) > 0:
                 asm_code = b"".join([x.bytes for x in insns])
+                assert cemu.core.context
                 elf = cemu.exports.build_pe_executable(asm_code, memory_layout, cemu.core.context.architecture)
                 info(f"ELF file written as '{elf}'")
         except Exception as e:
@@ -610,9 +637,14 @@ def onUpdateArchitecture(self, arch: Architecture, endian: Optional[Endianness]
             arch (Architecture): the newly selected architecture
         """
         label = f"{arch.name:s} / Endian: {str(arch.endianness)} / Syntax: {str(arch.syntax)}"
+        if self.currentAction is None:
+            dbg("No current action defined")
+            return
         self.currentAction.setEnabled(True)
+        assert cemu.core.context
         cemu.core.context.architecture = arch
         if endian:
+            assert cemu.core.context
             cemu.core.context.architecture.endianness = endian
         info(f"Switching to '{label}'")
         self.__regsWidget.updateGrid()
@@ -623,6 +655,7 @@ def onUpdateArchitecture(self, arch: Architecture, endian: Optional[Endianness]
 
     def refreshWindowTitle(self) -> None:
         """Refresh the main window title bar"""
+        assert cemu.core.context
         title = f"{TITLE} ({cemu.core.context.architecture})"
         if self.current_file:
             title += f": {self.current_file.name}"
@@ -651,12 +684,14 @@ def showShortcutPopup(self):
 
         wid.setMinimumWidth(800)
         wid.setLayout(grid)
-        msgbox.layout().addWidget(wid)
+        msgbox_layout = msgbox.layout()
+        if msgbox_layout:
+            msgbox_layout.addWidget(wid)
         msgbox.exec()
         return
 
     def about_popup(self):
-        templ = (TEMPLATE_PATH / "about.html").open().read()
+        templ = (TEMPLATE_PATH / "about.html").read_text()
         desc = templ.format(author=AUTHOR, version=VERSION, project_link=URL, issues_link=ISSUE_LINK)
         msgbox = QMessageBox(self)
         msgbox.setIcon(QMessageBox.Icon.Information)
@@ -675,6 +710,7 @@ def updateRecentFileActions(self, insert_file=None):
             settings.setValue("recentFileList", [])
             files = settings.value("recentFileList")
 
+        assert cemu.core.context
         maxRecentFiles = cemu.core.context.settings.getint("Default", "MaxRecentFiles")
 
         if insert_file:
@@ -722,23 +758,28 @@ def get_memory_layout(self) -> list[MemorySection]:
         """
         Returns the memory layout as defined by the __mapWidget values as a structured list.
         """
+        assert cemu.core.context
         return cemu.core.context.emulator.sections
 
     def update_layout_not_running(self):
-        self.statusBar().showMessage("Not running")
-        return
+        statusBar = self.statusBar()
+        assert statusBar
+        statusBar.showMessage("Not running")
 
     def update_layout_running(self):
-        self.statusBar().showMessage("Running")
-        return
+        statusBar = self.statusBar()
+        assert statusBar
+        statusBar.showMessage("Running")
 
     def update_layout_step_running(self):
-        self.statusBar().showMessage("Idle (Step Mode)")
-        return
+        statusBar = self.statusBar()
+        assert statusBar
+        statusBar.showMessage("Idle (Step Mode)")
 
     def update_layout_step_finished(self):
-        self.statusBar().showMessage("Finished")
-        return
+        statusBar = self.statusBar()
+        assert statusBar
+        statusBar.showMessage("Finished")
 
 
 class EmulationRunner:
@@ -748,6 +789,7 @@ def run(self):
         """
         Runs the emulation
         """
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         if not emu.vm:
             error("VM is not ready")
diff --git a/src/cemu/ui/mapping.py b/src/cemu/ui/mapping.py
index 2057cf1..649a0fd 100644
--- a/src/cemu/ui/mapping.py
+++ b/src/cemu/ui/mapping.py
@@ -19,7 +19,7 @@
 from cemu.emulator import Emulator, EmulatorState
 from cemu.log import error
 from cemu.memory import MemorySection
-from cemu.utils import format_address
+from cemu.arch import format_address
 
 from .utils import popup
 
@@ -42,7 +42,9 @@ def __init__(self, parent: "CEmuWindow"):
         self.MemoryMapTableWidget.setColumnWidth(3, 120)
         self.MemoryMapTableWidget.setSelectionBehavior(QTableWidget.SelectionBehavior.SelectRows)
         self.MemoryMapTableWidget.setHorizontalHeaderLabels(["Start", "End", "Name", "Permission"])
-        self.MemoryMapTableWidget.verticalHeader().setVisible(False)
+        vHeader = self.MemoryMapTableWidget.verticalHeader()
+        if vHeader:
+            vHeader.setVisible(False)
         layout.addWidget(self.MemoryMapTableWidget)
 
         # add/remove buttons
@@ -64,6 +66,7 @@ def __init__(self, parent: "CEmuWindow"):
         #
         # Emulator state callback
         #
+        assert cemu.core.context
         self.emu: Emulator = cemu.core.context.emulator
         self.emu.add_state_change_cb(EmulatorState.NOT_RUNNING, self.onNotRunningUpdateMemoryMap)
         self.emu.add_state_change_cb(EmulatorState.RUNNING, self.onRunningDisableMemoryMapGrid)
@@ -111,13 +114,14 @@ def onDeleteSectionButtonClicked(self) -> None:
         Callback associated with the click of the "Remove Section" button
         """
         selection = self.MemoryMapTableWidget.selectionModel()
-        if not selection.hasSelection():
+        if not selection or not selection.hasSelection():
             return
 
         indexes = [x.row() for x in selection.selectedRows()]
 
         for idx in range(len(self.emu.sections) - 1, 0, -1):
             if idx in indexes:
+                assert cemu.core.context
                 del cemu.core.context.emulator.sections[idx]
         self.redraw_memory_map_table()
         return
@@ -169,6 +173,7 @@ def add_or_edit_section_popup(self) -> None:
 
         msgbox.setWindowTitle("Add section")
         layout = msgbox.layout()
+        assert layout
         wid.setLayout(grid)
         wid.setMinimumWidth(400)
         layout.addWidget(wid)
@@ -181,10 +186,12 @@ def add_or_edit_section_popup(self) -> None:
             address = int(startAddressEdit.text(), 0)
             size = int(sizeEdit.text(), 0)
 
+            assert cemu.core.context
             if name in (x.name for x in cemu.core.context.emulator.sections):
                 error("section name already exists")
                 return
 
+            assert cemu.core.context
             memory_set = (set(range(x.address, x.address + x.size)) for x in cemu.core.context.emulator.sections)
             current_set = set(range(address, address + size))
             for m in memory_set:
@@ -201,6 +208,7 @@ def add_or_edit_section_popup(self) -> None:
                 section_perm.append("EXEC")
             try:
                 section = MemorySection(name, address, size, "|".join(section_perm))
+                assert cemu.core.context
                 cemu.core.context.emulator.sections.append(section)
                 self.redraw_memory_map_table()
             except ValueError as ve:
@@ -211,6 +219,7 @@ def add_or_edit_section_popup(self) -> None:
                 section_perm.append("EXEC")
             try:
                 section = MemorySection(name, address, size, "|".join(section_perm))
+                assert cemu.core.context
                 cemu.core.context.emulator.sections.append(section)
                 self.redraw_memory_map_table()
             except ValueError as ve:
diff --git a/src/cemu/ui/memory.py b/src/cemu/ui/memory.py
index 4985f9d..31a9758 100644
--- a/src/cemu/ui/memory.py
+++ b/src/cemu/ui/memory.py
@@ -59,6 +59,7 @@ def __init__(self, parent: CEmuWindow, *args, **kwargs):
         #
         # Emulator state callback
         #
+        assert cemu.core.context
         emu: Emulator = cemu.core.context.emulator
         emu.add_state_change_cb(EmulatorState.IDLE, self.onIdleRefreshMemoryEditor)
         emu.add_state_change_cb(EmulatorState.FINISHED, self.onFinishedClearMemoryEditor)
@@ -66,7 +67,9 @@ def __init__(self, parent: CEmuWindow, *args, **kwargs):
         return
 
     def updateEditor(self) -> None:
+        assert cemu.core.context
         arch = cemu.core.context.architecture
+        assert cemu.core.context
         emu = cemu.core.context.emulator
         if not emu.vm:
             self.editor.setText("VM not initialized")
diff --git a/src/cemu/ui/registers.py b/src/cemu/ui/registers.py
index a95765f..3449721 100644
--- a/src/cemu/ui/registers.py
+++ b/src/cemu/ui/registers.py
@@ -17,7 +17,8 @@
     DEFAULT_REGISTER_VIEW_REGISTER_FONT_SIZE,
 )
 from cemu.emulator import Emulator, EmulatorState
-from cemu.utils import format_address
+from cemu.arch import format_address
+import cemu.emulator
 
 
 class RegistersWidget(QDockWidget):
@@ -28,9 +29,13 @@ def __init__(self, parent, *args, **kwargs):
         self.__old_register_values = {}
         layout = QVBoxLayout()
         self.RegisterTableWidget = QTableWidget(10, 2)
-        self.RegisterTableWidget.horizontalHeader().setStretchLastSection(True)
+        hHeader = self.RegisterTableWidget.horizontalHeader()
+        if hHeader:
+            hHeader.setStretchLastSection(True)
         self.RegisterTableWidget.setHorizontalHeaderLabels(["Register", "Value"])
-        self.RegisterTableWidget.verticalHeader().setVisible(False)
+        vHeader = self.RegisterTableWidget.verticalHeader()
+        if vHeader:
+            vHeader.setVisible(False)
         self.RegisterTableWidget.setColumnWidth(0, 80)
         layout.addWidget(self.RegisterTableWidget)
 
@@ -45,6 +50,7 @@ def __init__(self, parent, *args, **kwargs):
         #
         # Emulator state callback
         #
+        assert cemu.core.context
         emu: Emulator = cemu.core.context.emulator
         emu.add_state_change_cb(EmulatorState.IDLE, self.onIdleRefreshRegisterGrid)
         emu.add_state_change_cb(EmulatorState.FINISHED, self.onFinishedRefreshRegisterGrid)
@@ -56,7 +62,9 @@ def updateGrid(self) -> None:
         VM CPU registers
 
         """
+        assert cemu.core.context
         emu: Emulator = cemu.core.context.emulator
+        assert cemu.core.context
         arch = cemu.core.context.architecture
         registers = arch.registers
         self.RegisterTableWidget.setRowCount(len(registers))
@@ -93,16 +101,21 @@ def updateGrid(self) -> None:
         #
         # Propagate the change to the emulator
         #
-        cemu.core.context.emulator.registers = self.getRegisterValuesFromGrid()
+        assert cemu.core.context
+        cemu.core.context.emulator.registers = cemu.emulator.EmulationRegisters(self.getRegisterValuesFromGrid())
         return
 
     def getRegisterValuesFromGrid(self) -> dict[str, int]:
         """Returns the current values of the registers, as shown by the widget grid"""
         regs = {}
+        assert cemu.core.context
         registers = cemu.core.context.emulator.registers.keys()
         for i in range(len(registers)):
-            name = self.RegisterTableWidget.item(i, 0).text()
-            value = self.RegisterTableWidget.item(i, 1).text()
+            item1 = self.RegisterTableWidget.item(i, 0)
+            name = item1.text() if item1 else ""
+
+            item2 = self.RegisterTableWidget.item(i, 1)
+            value = item2.text() if item2 else "0"
             regs[name] = int(value, 16)
         return regs
 
diff --git a/src/cemu/utils.py b/src/cemu/utils.py
index 7c00477..8975823 100644
--- a/src/cemu/utils.py
+++ b/src/cemu/utils.py
@@ -1,15 +1,12 @@
 import os
-import pathlib
+
 import random
 import string
-from dataclasses import dataclass
 from typing import Optional, TYPE_CHECKING
 
 if TYPE_CHECKING:
     import cemu.arch
-import cemu.core
-import cemu.errors
-import cemu.utils
+
 from cemu.const import COMMENT_MARKER, PROPERTY_MARKER
 from cemu.log import dbg
 
@@ -35,6 +32,17 @@ def hexdump(
     Returns:
         str: _description_
     """
+    import cemu.arch
+
+    if not isinstance(source, bytes):
+        raise ValueError("source must be of type `bytes`")
+
+    if len(separator) != 1:
+        raise ValueError("separator must be a single character")
+
+    if (alignment & 1) == 1:
+        raise ValueError("alignment must be a multiple of two")
+
     result: list[str] = []
     for i in range(0, len(source), alignment):
         chunk = source[i : i + alignment]
@@ -44,125 +52,18 @@ def hexdump(
         if show_raw:
             result.append(hexa)
         else:
-            result.append(f"{format_address(base)}  {hexa}  {text}")
+            result.append(f"{cemu.arch.format_address(base+i)}  {hexa}  {text}")
 
     return os.linesep.join(result)
 
 
-def format_address(addr: int, arch: Optional[cemu.arch.Architecture] = None) -> str:
-    """Format an address to string, aligned to the given architecture
-
-    Args:
-        addr (int): _description_
-        arch (Optional[Architecture], optional): _description_. Defaults to None.
-
-    Raises:
-        ValueError: _description_
-
-    Returns:
-        str: _description_
-    """
-    if arch is None:
-        arch = cemu.core.context.architecture
-
-    if arch.ptrsize == 2:
-        return f"{addr:#04x}"
-    elif arch.ptrsize == 4:
-        return f"{addr:#08x}"
-    elif arch.ptrsize == 8:
-        return f"{addr:#016x}"
-    else:
-        raise ValueError(f"Invalid value for '{arch.ptrsize=}'")
-
-
-@dataclass
-class Instruction:
-    address: int
-    mnemonic: str
-    operands: str
-    bytes: bytes
-
-    @property
-    def size(self):
-        return len(self.bytes)
-
-    @property
-    def end(self) -> int:
-        return self.address + self.size
-
-    def __str__(self):
-        return f'Instruction({self.address:#x}, "{self.mnemonic} {self.operands}")'
-
-
-def disassemble(raw_data: bytes, count: int = -1, base: int = DISASSEMBLY_DEFAULT_BASE_ADDRESS) -> list[Instruction]:
-    """Disassemble the code given as raw data, with the given architecture.
-
-    Args:
-        raw_data (bytes): the raw byte code to disassemble
-        arch (Architecture): the architecture to use for disassembling
-        count (int, optional): the maximum number of instruction to disassemble. Defaults to -1.
-        base (int, optional): the disassembled code base address. Defaults to DISASSEMBLY_DEFAULT_BASE_ADDRESS
-
-    Returns:
-        str: the text representation of the disassembled code
-    """
-    arch = cemu.core.context.architecture
-    insns: list[Instruction] = []
-    for idx, ins in enumerate(arch.cs.disasm(raw_data, base)):
-        insn = Instruction(ins.address, ins.mnemonic, ins.op_str, ins.bytes)
-        insns.append(insn)
-        if idx == count:
-            break
-
-    dbg(f"{insns=}")
-    return insns
-
-
-def disassemble_file(fpath: pathlib.Path) -> list[Instruction]:
-    with fpath.open("rb") as f:
-        return disassemble(f.read())
-
-
-def assemble(code: str, base_address: int = DISASSEMBLY_DEFAULT_BASE_ADDRESS) -> list[Instruction]:
-    """
-    Helper function to assemble code receive in parameter `asm_code` using Keystone.
-
-    @param code : assembly code in bytes (multiple instructions must be separated by ';')
-    @param base_address : (opt) the base address to use
-
-    @return a list of Instruction
-    """
-    arch = cemu.core.context.architecture
-
-    #
-    # Compile the entire given code
-    #
-    bytecode, assembled_insn_count = arch.ks.asm(code, as_bytes=True, addr=base_address)
-    if not bytecode or assembled_insn_count == 0:
-        raise cemu.errors.AssemblyException("Not instruction compiled")
-
-    assert isinstance(bytecode, bytes)
-
-    #
-    # Decompile it and return the stuff
-    #
-    insns = disassemble(bytecode, base=base_address)
-    dbg(f"{insns=}")
-    return insns
-
-
-def assemble_file(fpath: pathlib.Path) -> list[Instruction]:
-    with fpath.open("r") as f:
-        return assemble(f.read())
-
-
 def ishex(x: str) -> bool:
     if x.lower().startswith("0x"):
         x = x[2:]
     return all([c in string.hexdigits for c in x])
 
 
-def generate_random_string(length: int) -> str:
+def generate_random_string(length: int, charset: str = string.ascii_letters + string.digits) -> str:
     """Returns a random string
 
     Args:
@@ -171,13 +72,15 @@ def generate_random_string(length: int) -> str:
     Returns:
         str: _description_
     """
-    charset = string.ascii_letters + string.digits
+    if length < 1:
+        raise ValueError("invalid length")
+
     return "".join(random.choice(charset) for _ in range(length))
 
 
 def get_metadata_from_stream(
     content: str,
-) -> Optional[tuple[cemu.arch.Architecture, cemu.arch.Endianness]]:
+) -> Optional[tuple["cemu.arch.Architecture", "cemu.arch.Endianness"]]:
     """Parse a file content to automatically extract metadata. Metadata can only be passed in the file
     header, and *must* be a commented line (i.e. starting with `;;; `) followed by the property marker (i.e. `@@@`).
     Both the architecture and endianess *must* be provided
@@ -190,23 +93,30 @@ def get_metadata_from_stream(
         content (str): _description_
 
     Returns:
-        Optional[tuple[str, str]]: _description_
+        Optional[tuple[Architecture, Endianness]]: _description_
 
     Raises:
         KeyError:
             - if an architecture metadata is found, but invalid
             - if an endianess metadata is found, but invalid
     """
-    arch: Optional[cemu.arch.Architecture] = None
-    endian: Optional[cemu.arch.Endianness] = None
+    import cemu.arch
+
+    arch: Optional["cemu.arch.Architecture"] = None
+    endian: Optional["cemu.arch.Endianness"] = None
 
     for line in content.splitlines():
+        # if already set, don't bother continuing
+        if arch and endian:
+            return (arch, endian)
+
+        # validate the line format
         part = line.strip().split()
-        if len(part) < 4:
-            return None
+        if len(part) != 3:
+            continue
 
-        if (part[0] != COMMENT_MARKER) and (arch and endian):
-            return (arch, endian)
+        if part[0] != COMMENT_MARKER:
+            continue
 
         if not part[1].startswith(PROPERTY_MARKER):
             continue
@@ -216,16 +126,17 @@ def get_metadata_from_stream(
 
         if metadata_type == "architecture" and not arch:
             arch = cemu.arch.Architectures.find(metadata_value)
-            dbg(f"Forcing architecture '{arch}'")
+            dbg(f"Setting architecture from metadata to '{arch}'")
             continue
 
         if metadata_type == "endianness" and not endian:
-            if metadata_value == "little":
-                endian = cemu.arch.Endianness.LITTLE_ENDIAN
-            elif metadata_value == "big":
-                endian = cemu.arch.Endianness.BIG_ENDIAN
-            else:
-                continue
-            dbg(f"Forcing endianness '{endian}'")
+            match metadata_value:
+                case "little":
+                    endian = cemu.arch.Endianness.LITTLE_ENDIAN
+                case "big":
+                    endian = cemu.arch.Endianness.BIG_ENDIAN
+                case _:
+                    raise ValueError
+            dbg(f"Setting endianness from metadata to '{endian}'")
 
     return None
diff --git a/tests/test_arch.py b/tests/test_arch.py
new file mode 100644
index 0000000..4ac5090
--- /dev/null
+++ b/tests/test_arch.py
@@ -0,0 +1,84 @@
+import pathlib
+import cemu
+import cemu.arch
+import cemu.core
+
+assert cemu.__package__
+assert len(cemu.__package__) >= 1
+
+CURRENT_FILE = pathlib.Path(__file__)
+CURRENT_DIR = CURRENT_FILE.parent
+CEMU_PACKAGE_ROOT = CURRENT_DIR / "../src/cemu"
+CEMU_EXAMPLES_FOLDER = CEMU_PACKAGE_ROOT / "examples"
+
+
+def test_endianness_basic():
+    assert int(cemu.arch.Endianness.LITTLE_ENDIAN) == 1
+    assert int(cemu.arch.Endianness.BIG_ENDIAN) == 2
+    assert str(cemu.arch.Endianness.BIG_ENDIAN) == "Big Endian"
+    assert str(cemu.arch.Endianness.LITTLE_ENDIAN) == "Little Endian"
+
+
+def test_syntax_basic():
+    assert int(cemu.arch.Syntax.INTEL) == 1
+    assert str(cemu.arch.Syntax.INTEL) == "INTEL"
+    assert int(cemu.arch.Syntax.ATT) == 2
+    assert str(cemu.arch.Syntax.ATT) == "ATT"
+
+
+def test_architecture_manager():
+    archs = cemu.arch.Architectures
+    assert isinstance(archs, dict)
+
+
+def test_assemble_file():
+    cemu.core.context = cemu.core.GlobalContext()
+
+    def parse_syscalls(lines: list[str]) -> list[str]:
+        parsed = []
+        assert cemu.core.context
+        syscalls = cemu.core.context.architecture.syscalls
+        syscall_names = syscalls.keys()
+        for line in lines:
+            for sysname in syscall_names:
+                pattern = f"__NR_SYS_{sysname}"
+                if pattern in line:
+                    line = line.replace(pattern, str(syscalls[sysname]))
+            parsed.append(line)
+        return parsed
+
+    # Values:
+    # ['generic', 'x86_32', 'x86_64', 'x86', 'arm', 'aarch64', 'mips', 'mips64', 'sparc', 'sparc64']
+
+    for tc in (
+        "aarch64",
+        "arm",
+        "mips",
+        "sparc",
+        "x86_32",
+        "x86_64",
+    ):
+        cemu.core.context.architecture = cemu.arch.Architectures.find(tc)
+        fpath = CEMU_EXAMPLES_FOLDER / f"{tc}_sys_exec_bin_sh.asm"
+        code = ";".join(parse_syscalls([x.strip() for x in fpath.read_text().splitlines() if not x.strip().startswith(";;; ")]))
+        print(f"trying {tc} -> {cemu.core.context.architecture.syscalls}")
+        insns = cemu.arch.assemble(code)
+        assert len(insns) > 0
+
+
+def test_disassemble_file():
+    cemu.core.context = cemu.core.GlobalContext()
+
+    # Values:
+    # ['generic', 'x86_32', 'x86_64', 'x86', 'arm', 'aarch64', 'mips', 'mips64', 'sparc', 'sparc64']
+
+    for tc in ("arm", "sparc", "x86"):
+        cemu.core.context.architecture = cemu.arch.Architectures.find(tc)
+        insns = cemu.arch.disassemble_file(CEMU_EXAMPLES_FOLDER / f"{tc}_nops.raw")
+        assert len(insns) == 10
+
+
+def test_disassemble():
+    cemu.core.context = cemu.core.GlobalContext()
+    insns = cemu.arch.disassemble(b"\xcc")
+    assert len(insns) == 1
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 0e541d7..32045cf 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -179,6 +179,7 @@ def test_matrix_execute_assembly_regs(self):
             #
             # (Re-)Initialize the context
             #
+            assert cemu.core.context
             cemu.core.context.architecture = tc.arch
             self.emu.reset()
             self.emu.sections = MEMORY_MAP_DEFAULT_LAYOUT[:]
diff --git a/tests/test_utils.py b/tests/test_utils.py
new file mode 100644
index 0000000..8a82df6
--- /dev/null
+++ b/tests/test_utils.py
@@ -0,0 +1,61 @@
+import string
+import pytest
+
+import cemu.core
+import cemu.utils
+import cemu.arch
+
+
+def test_get_metadata_from_stream():
+    raw = r"""
+    ;;; @@@architecture x86_64
+    ;;; @@@endianness little
+    """
+    res = cemu.utils.get_metadata_from_stream(raw)
+    assert res and len(res) == 2
+    assert isinstance(res[0], cemu.arch.Architecture)
+    assert cemu.arch.is_x86_64(res[0])
+    assert isinstance(res[1], cemu.arch.Endianness)
+    assert res[1] == cemu.arch.Endianness.LITTLE_ENDIAN
+
+
+def test_generate_random_string():
+    assert len(cemu.utils.generate_random_string(5)) == 5
+    assert isinstance(cemu.utils.generate_random_string(5), str)
+    with pytest.raises(ValueError):
+        cemu.utils.generate_random_string(-5)
+
+    res = cemu.utils.generate_random_string(500, charset=string.ascii_letters)
+    assert all(filter(lambda x: x in string.ascii_letters, res))
+
+
+def test_ishex():
+    assert not cemu.utils.ishex("0Xasd")
+    assert cemu.utils.ishex("0123")
+    assert not cemu.utils.ishex("0123asd")
+    assert not cemu.utils.ishex("0x!!0123asd")
+    assert not cemu.utils.ishex("0123fff==")
+    assert cemu.utils.ishex("0123abcdef")
+
+
+def test_hexdump():
+    cemu.core.context = cemu.core.GlobalContext()
+    cemu.core.context.architecture = cemu.arch.Architectures.find("x86_32")
+    assert cemu.utils.hexdump(b"aaaa") == "0x000000  61 61 61 61  aaaa"
+    cemu.core.context.architecture = cemu.arch.Architectures.find("x86_64")
+    assert cemu.utils.hexdump(b"aaaa") == "0x00000000000000  61 61 61 61  aaaa"
+
+    with pytest.raises(ValueError):
+        cemu.utils.hexdump(b"aaaa", separator="")
+
+    assert cemu.utils.hexdump(b"\x41\x41\xff\xfe") == "0x00000000000000  41 41 FF FE  AA.."
+
+    with pytest.raises(ValueError):
+        cemu.utils.hexdump(b"A" * 0x20, alignment=3)
+
+    assert cemu.utils.hexdump(b"\x41\x41\xff\xfe", base=0x41414141_41414141) == "0x4141414141414141  41 41 FF FE  AA.."
+    res = cemu.utils.hexdump(b"A" * 0x20, base=0x41414141_41414141).splitlines()
+
+    assert len(res) == 2
+    assert res[0] == "0x4141414141414141  41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41  AAAAAAAAAAAAAAAA"
+    assert res[1] == "0x4141414141414151  41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41  AAAAAAAAAAAAAAAA"