diff --git a/code/scripts/espurna_utils/__init__.py b/code/scripts/espurna_utils/__init__.py
index f7b209d177..e2dca4db62 100644
--- a/code/scripts/espurna_utils/__init__.py
+++ b/code/scripts/espurna_utils/__init__.py
@@ -26,6 +26,7 @@
     app_add_gzip_file,
     app_add_target_build_re2c,
     app_patch_cachedir,
+    app_patch_elf2bin,
 )
 from .checks import check_env, check_binsize
 from .flags import app_inject_flags
diff --git a/code/scripts/espurna_utils/build.py b/code/scripts/espurna_utils/build.py
index aa7de96212..a3de246fa7 100644
--- a/code/scripts/espurna_utils/build.py
+++ b/code/scripts/espurna_utils/build.py
@@ -234,3 +234,28 @@ def patched_get_cachedir_bsig(self):
         return result
 
     File.get_cachedir_bsig = patched_get_cachedir_bsig
+
+
+# patch framework-arduinoespressif8266 @ 3.20704.0 (2.7.4) elf2bin .py
+# using modified platform_elf2bin.py, changed locally w/ upstream changes
+# ref. https://github.com/esp8266/Arduino/commits/3.1.2/tools/elf2bin.py
+# - backport 'Fix syntax warning' at https://github.com/esp8266/Arduino/pull/9034
+# - backport 'Use subprocess.run' at https://github.com/esp8266/Arduino/pull/8799
+# - only partially backport https://github.com/esp8266/Arduino/pull/7844
+#   as it changes eboot blob as well as crc location and .ld script(s)
+def app_patch_elf2bin(env):
+    KNOWN_PLATFORMS = ("2_6_3", "4_2_0")
+
+    platform = env.PioPlatform()
+    version = platform.version.replace(".", "_")
+
+    if not version in KNOWN_PLATFORMS:
+        return
+
+    builder = env["BUILDERS"]["ElfToBin"]
+
+    cmd_list = builder.action.cmd_list.split(' ')
+    elf2bin = env.File(cmd_list[1])
+
+    cmd_list[1] = env.subst(f"${{PROJECT_DIR}}/scripts/platform_elf2bin_{version}.py")
+    builder.action.cmd_list = ' '.join(cmd_list)
diff --git a/code/scripts/pio_main.py b/code/scripts/pio_main.py
index 245c7e7394..754aa0a29e 100644
--- a/code/scripts/pio_main.py
+++ b/code/scripts/pio_main.py
@@ -14,6 +14,7 @@
 
 from espurna_utils import (
     app_add_target_build_and_copy,
+    app_patch_elf2bin,
     app_inject_flags,
     app_inject_version,
     app_add_gzip_file,
@@ -94,3 +95,6 @@
 cachedir_fix = check_env("ESPURNA_FIX_CACHEDIR_PATH", "n")
 if cachedir_fix:
     app_patch_cachedir(projenv)
+
+# workaround for Core 2.7.4 python3.12 syntax warnings, merge upstream changes
+app_patch_elf2bin(env)
diff --git a/code/scripts/platform_elf2bin_2_6_3.py b/code/scripts/platform_elf2bin_2_6_3.py
new file mode 100644
index 0000000000..2316374e38
--- /dev/null
+++ b/code/scripts/platform_elf2bin_2_6_3.py
@@ -0,0 +1,225 @@
+#!/usr/bin/env python3
+
+# Generate an Arduino compatible BIN file from bootloader and sketch ELF
+# Replaces esptool-ck.exe and emulates its behavior.
+#
+# Copyright (C) 2019 - Earle F. Philhower, III
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+from __future__ import print_function
+import argparse
+import io
+import re
+import os
+import subprocess
+import sys
+import tempfile
+
+fmodeb = { 'dout': 3, 'dio': 2, 'qout': 1, 'qio': 0 }
+ffreqb = { '40': 0, '26': 1, '20': 2, '80': 15 }
+fsizeb = { '512K': 0, '256K': 1, '1M': 2, '2M': 3, '4M': 4, '8M': 8, '16M': 9 }
+
+crcsize_offset = 4088
+crcval_offset = 4092
+
+
+class Elf2BinException(Exception):
+    pass
+
+
+def get_elf_entry(elf, path):
+    result = subprocess.run(
+        [os.path.join(path, "xtensa-lx106-elf-readelf"), "-h", elf],
+        check=True,
+        timeout=15,
+        stdout=subprocess.PIPE,
+        universal_newlines=True,
+    )
+
+    lines = io.StringIO(result.stdout)
+    for line in lines.readlines():
+        if 'Entry point address' in line:
+            words = re.split(r'\s+', line)
+            entry_point = words[-2]
+            return int(entry_point, 16)
+
+    raise Elf2BinException(f'Unable to find entry point in file "{elf}"')
+
+
+def get_segment_size_addr(elf, segment, path):
+    result = subprocess.run(
+        [os.path.join(path, "xtensa-lx106-elf-objdump"), "-h", "-j", segment, elf],
+        check=True,
+        timeout=15,
+        stdout=subprocess.PIPE,
+        universal_newlines=True,
+    )
+
+    lines = io.StringIO(result.stdout)
+    for line in lines.readlines():
+        if segment in line:
+            words = re.split(r'\s+', line)
+            size = int(words[3], 16)
+            addr = int(words[4], 16)
+            return [ size, addr ]
+
+    raise Elf2BinException(
+        f'Unable to find size and start point in file "{elf}" for "{segment}"'
+    )
+
+
+def read_segment(elf, segment, path):
+    fd, tmpfile = tempfile.mkstemp()
+    os.close(fd)
+    try:
+        subprocess.check_call(
+            [
+                os.path.join(path, "xtensa-lx106-elf-objcopy"),
+                "-O",
+                "binary",
+                f"--only-section={segment}",
+                elf,
+                tmpfile,
+            ],
+            stdout=subprocess.PIPE,
+        )
+        with open(tmpfile, "rb") as f:
+            raw = f.read()
+    finally:
+        os.remove(tmpfile)
+
+    return raw
+
+
+def write_bin(out, args, elf, segments, to_addr):
+    entry = int(get_elf_entry( elf, args.path ))
+    header = [ 0xe9, len(segments), fmodeb[args.flash_mode], ffreqb[args.flash_freq] + 16 * fsizeb[args.flash_size],
+               entry & 255, (entry>>8) & 255, (entry>>16) & 255, (entry>>24) & 255 ]
+    out.write(bytearray(header))
+    total_size = 8
+    checksum = 0xef
+    for segment in segments:
+        [size, addr] = get_segment_size_addr(elf, segment, args.path)
+        seghdr = [ addr & 255, (addr>>8) & 255, (addr>>16) & 255, (addr>>24) & 255,
+                   size & 255, (size>>8) & 255, (size>>16) & 255, (size>>24) & 255]
+        out.write(bytearray(seghdr));
+        total_size += 8;
+        raw = read_segment(elf, segment, args.path)
+        if len(raw) != size:
+            raise Exception('Segment size doesn\'t match read data for "' + segment + '" in "' + elf + '"')
+        out.write(raw)
+        total_size += len(raw)
+        try:
+            for data in raw:
+                checksum = checksum ^ ord(data)
+        except:
+            for data in raw:
+                checksum = checksum ^ data
+    total_size += 1
+    while total_size & 15:
+        total_size += 1
+        out.write(bytearray([0]))
+    out.write(bytearray([checksum]))
+    if to_addr != 0:
+        if total_size + 8 > to_addr:
+            raise Elf2BinException(
+                f'Bin image of "{elf}" is too big! Actual size {str(total_size  + 8)}, target size {str(to_addr)}'
+            )
+        while total_size < to_addr:
+            out.write(bytearray([0xaa]))
+            total_size += 1
+
+
+def crc8266(ldata):
+    "Return the CRC of ldata using same algorithm as eboot"
+    crc = 0xffffffff
+    idx = 0
+    while idx < len(ldata):
+        byte = int(ldata[idx])
+        idx = idx + 1
+        for i in [0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01]:
+            bit = crc & 0x80000000
+            if (byte & i) != 0:
+                if bit == 0:
+                    bit = 1
+                else:
+                    bit = 0
+            crc = int(crc << 1) & 0xffffffff
+            if bit != 0:
+                crc = int(crc ^ 0x04c11db7)
+    return crc
+
+
+def store_word(raw, offset, val):
+    "Place a 4-byte word in 8266-dependent order in the raw image"
+    raw[offset] = val & 255
+    raw[offset + 1] = (val >> 8) & 255
+    raw[offset + 2] = (val >> 16) & 255
+    raw[offset + 3] = (val >> 24) & 255
+    return raw
+
+
+def add_crc(out):
+    with open(out, "rb") as binfile:
+        raw = bytearray(binfile.read())
+
+    # Zero out the spots we're going to overwrite to be idempotent
+    raw = store_word(raw, crcsize_offset, 0)
+    raw = store_word(raw, crcval_offset, 0)
+    crc = crc8266(raw)
+    raw = store_word(raw, crcsize_offset, len(raw))
+    raw = store_word(raw, crcval_offset, int(crc))
+
+    with open(out, "wb") as binfile:
+        binfile.write(raw)
+
+def main():
+    parser = argparse.ArgumentParser(description='Create a BIN file from eboot.elf and Arduino sketch.elf for upload by esptool.py')
+    parser.add_argument('-e', '--eboot', action='store', required=True, help='Path to the Arduino eboot.elf bootloader')
+    parser.add_argument('-a', '--app', action='store', required=True, help='Path to the Arduino sketch ELF')
+    parser.add_argument('-m', '--flash_mode', action='store', required=True, choices=['dout', 'dio', 'qout', 'qio'], help='SPI flash mode')
+    parser.add_argument('-f', '--flash_freq', action='store', required=True, choices=['20', '26', '40', '80'], help='SPI flash speed')
+    parser.add_argument('-s', '--flash_size', action='store', required=True, choices=['256K', '512K', '1M', '2M', '4M', '8M', '16M'], help='SPI flash size')
+    parser.add_argument('-o', '--out', action='store', required=True, help='Output BIN filename')
+    parser.add_argument('-p', '--path', action='store', required=True, help='Path to Xtensa toolchain binaries')
+
+    args = parser.parse_args()
+
+    print(f'Creating BIN file "{args.out}" using "{args.eboot}" and "{args.app}"')
+
+    with open(args.out, "wb") as out:
+        def wrapper(**kwargs):
+            write_bin(out=out, args=args, **kwargs)
+
+        wrapper(
+            elf=args.eboot,
+            segments=[".text"],
+            to_addr=4096
+        )
+
+        wrapper(
+            elf=args.app,
+            segments=[".irom0.text", ".text", ".text1", ".data", ".rodata"],
+            to_addr=0
+        )
+
+    # Because the CRC includes both eboot and app, can only calculate it after the entire BIN generated
+    add_crc(args.out)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/code/scripts/platform_elf2bin_4_2_0.py b/code/scripts/platform_elf2bin_4_2_0.py
new file mode 100644
index 0000000000..b8248c5334
--- /dev/null
+++ b/code/scripts/platform_elf2bin_4_2_0.py
@@ -0,0 +1,256 @@
+#!/usr/bin/env python3
+
+# Generate an Arduino compatible BIN file from bootloader and sketch ELF
+# Replaces esptool-ck.exe and emulates its behavior.
+#
+# Copyright (C) 2019 - Earle F. Philhower, III
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+from __future__ import print_function
+import argparse
+import io
+import re
+import os
+import subprocess
+import sys
+import tempfile
+
+fmodeb = { 'dout': 3, 'dio': 2, 'qout': 1, 'qio': 0 }
+ffreqb = { '40': 0, '26': 1, '20': 2, '80': 15 }
+fsizeb = { '512K': 0, '256K': 1, '1M': 2, '2M': 3, '4M': 4, '8M': 8, '16M': 9 }
+
+crcsize_offset = 4096 + 16
+crcval_offset =  4096 + 16 + 4
+
+
+class Elf2BinException(Exception):
+    pass
+
+
+def get_elf_entry(elf, path):
+    result = subprocess.run(
+        [os.path.join(path, "xtensa-lx106-elf-readelf"), "-h", elf],
+        check=True,
+        timeout=15,
+        stdout=subprocess.PIPE,
+        universal_newlines=True,
+    )
+
+    lines = io.StringIO(result.stdout)
+    for line in lines.readlines():
+        if 'Entry point address' in line:
+            words = re.split(r'\s+', line)
+            entry_point = words[-2]
+            return int(entry_point, 16)
+
+    raise Elf2BinException(f'Unable to find entry point in file "{elf}"')
+
+
+def get_segment_size_addr(elf, segment, path):
+    result = subprocess.run(
+        [os.path.join(path, "xtensa-lx106-elf-objdump"), "-h", "-j", segment, elf],
+        check=True,
+        timeout=15,
+        stdout=subprocess.PIPE,
+        universal_newlines=True,
+    )
+
+    lines = io.StringIO(result.stdout)
+    for line in lines.readlines():
+        if segment in line:
+            words = re.split(r'\s+', line)
+            size = int(words[3], 16)
+            addr = int(words[4], 16)
+            return [ size, addr ]
+
+    raise Elf2BinException(
+        f'Unable to find size and start point in file "{elf}" for "{segment}"'
+    )
+
+
+def read_segment(elf, segment, path):
+    fd, tmpfile = tempfile.mkstemp()
+    os.close(fd)
+    try:
+        subprocess.check_call(
+            [
+                os.path.join(path, "xtensa-lx106-elf-objcopy"),
+                "-O",
+                "binary",
+                f"--only-section={segment}",
+                elf,
+                tmpfile,
+            ],
+            stdout=subprocess.PIPE,
+        )
+        with open(tmpfile, "rb") as f:
+            raw = f.read()
+    finally:
+        os.remove(tmpfile)
+
+    return raw
+
+
+def write_bin(out, args, elf, segments, to_addr):
+    entry = int(get_elf_entry( elf, args.path ))
+    header = [ 0xe9, len(segments), fmodeb[args.flash_mode], ffreqb[args.flash_freq] + 16 * fsizeb[args.flash_size],
+               entry & 255, (entry>>8) & 255, (entry>>16) & 255, (entry>>24) & 255 ]
+    out.write(bytearray(header))
+    total_size = 8
+    checksum = 0xef
+    for segment in segments:
+        [size, addr] = get_segment_size_addr(elf, segment, args.path)
+        seghdr = [ addr & 255, (addr>>8) & 255, (addr>>16) & 255, (addr>>24) & 255,
+                   size & 255, (size>>8) & 255, (size>>16) & 255, (size>>24) & 255]
+        out.write(bytearray(seghdr));
+        total_size += 8;
+        raw = read_segment(elf, segment, args.path)
+        if len(raw) != size:
+            raise Exception('Segment size doesn\'t match read data for "' + segment + '" in "' + elf + '"')
+        out.write(raw)
+        total_size += len(raw)
+        try:
+            for data in raw:
+                checksum = checksum ^ ord(data)
+        except:
+            for data in raw:
+                checksum = checksum ^ data
+    total_size += 1
+    while total_size & 15:
+        total_size += 1
+        out.write(bytearray([0]))
+    out.write(bytearray([checksum]))
+    if to_addr != 0:
+        if total_size + 8 > to_addr:
+            raise Elf2BinException(
+                f'Bin image of "{elf}" is too big! Actual size {str(total_size  + 8)}, target size {str(to_addr)}'
+            )
+        while total_size < to_addr:
+            out.write(bytearray([0xaa]))
+            total_size += 1
+
+
+def crc8266(ldata):
+    "Return the CRC of ldata using same algorithm as eboot"
+    crc = 0xffffffff
+    idx = 0
+    while idx < len(ldata):
+        byte = int(ldata[idx])
+        idx = idx + 1
+        for i in [0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01]:
+            bit = crc & 0x80000000
+            if (byte & i) != 0:
+                if bit == 0:
+                    bit = 1
+                else:
+                    bit = 0
+            crc = int(crc << 1) & 0xffffffff
+            if bit != 0:
+                crc = int(crc ^ 0x04c11db7)
+    return crc
+
+
+def store_word(raw, offset, val):
+    "Place a 4-byte word in 8266-dependent order in the raw image"
+    raw[offset] = val & 255
+    raw[offset + 1] = (val >> 8) & 255
+    raw[offset + 2] = (val >> 16) & 255
+    raw[offset + 3] = (val >> 24) & 255
+    return raw
+
+
+def add_crc(out):
+    with open(out, "rb") as binfile:
+        raw = bytearray(binfile.read())
+
+    # Zero out the spots we're going to overwrite to be idempotent
+    raw = store_word(raw, crcsize_offset, 0)
+    raw = store_word(raw, crcval_offset, 0)
+    crc = crc8266(raw)
+    raw = store_word(raw, crcsize_offset, len(raw))
+    raw = store_word(raw, crcval_offset, int(crc))
+
+    with open(out, "wb") as binfile:
+        binfile.write(raw)
+
+
+def gzip_bin(mode, out):
+    import gzip
+
+    firmware_path = out
+    gzip_path = f"{firmware_path}.gz"
+    orig_path = f"{firmware_path}.orig"
+    if os.path.exists(gzip_path):
+        os.remove(gzip_path)
+    print(f'GZipping firmware {firmware_path}')
+    with open(firmware_path, 'rb') as firmware_file, \
+            gzip.open(gzip_path, 'wb') as dest:
+        data = firmware_file.read()
+        dest.write(data)
+    orig_size = os.stat(firmware_path).st_size
+    gzip_size = os.stat(gzip_path).st_size
+    print("New FW size {:d} bytes vs old {:d} bytes".format(
+        gzip_size, orig_size))
+
+    if mode == "PIO":
+        if os.path.exists(orig_path):
+            os.remove(orig_path)
+        print(f'Moving original firmware to {orig_path}')
+        os.rename(firmware_path, orig_path)
+        os.rename(gzip_path, firmware_path)
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Create a BIN file from eboot.elf and Arduino sketch.elf for upload by esptool.py')
+    parser.add_argument('-e', '--eboot', action='store', required=True, help='Path to the Arduino eboot.elf bootloader')
+    parser.add_argument('-a', '--app', action='store', required=True, help='Path to the Arduino sketch ELF')
+    parser.add_argument('-m', '--flash_mode', action='store', required=True, choices=['dout', 'dio', 'qout', 'qio'], help='SPI flash mode')
+    parser.add_argument('-f', '--flash_freq', action='store', required=True, choices=['20', '26', '40', '80'], help='SPI flash speed')
+    parser.add_argument('-s', '--flash_size', action='store', required=True, choices=['256K', '512K', '1M', '2M', '4M', '8M', '16M'], help='SPI flash size')
+    parser.add_argument('-o', '--out', action='store', required=True, help='Output BIN filename')
+    parser.add_argument('-p', '--path', action='store', required=True, help='Path to Xtensa toolchain binaries')
+    parser.add_argument('-g', '--gzip', choices=['PIO', 'Arduino'], help='PIO - generate gzipped BIN file, Arduino - generate BIN and BIN.gz')
+
+    args = parser.parse_args()
+
+    print(f'Creating BIN file "{args.out}" using "{args.eboot}" and "{args.app}"')
+
+    with open(args.out, "wb") as out:
+        def wrapper(**kwargs):
+            write_bin(out=out, args=args, **kwargs)
+
+        wrapper(
+            elf=args.eboot,
+            segments=[".text", ".rodata"],
+            to_addr=4096
+        )
+
+        wrapper(
+            elf=args.app,
+            segments=[".irom0.text", ".text", ".text1", ".data", ".rodata"],
+            to_addr=0
+        )
+
+    # Because the CRC includes both eboot and app, can only calculate it after the entire BIN generated
+    add_crc(args.out)
+
+    if args.gzip:
+        gzip_bin(args.gzip, args.out)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())