H8/536 ROM Decompiler

This repo now includes a standalone Python helper for the H8/536 ROM image:

python h8536_decompiler.py ROM\M27C512@DIP28_1.BIN --out build\rom_decompiled.asm --json build\rom_decompiled.json

On this machine the Windows python.exe entry is a Microsoft Store launcher stub, so validation was run with WSL:

ubuntu.exe run python3 h8536_decompiler.py --out build/rom_decompiled.asm --json build/rom_decompiled.json

What It Does

Decodes the H8/500 instruction set used by the H8/536.
Reads the H8/536 minimum-mode vector table from the ROM.
Recursively traces reachable code from reset, interrupt, and trap vectors.
Emits labels for branch and call targets.
Annotates H8/536 on-chip register accesses such as P1DDR, SYSCR1, WCR, and timer/SCI/A-D registers.
Handles the E-clock transfer instructions MOVFPE and MOVTPE.

The generated listing is written to:

build/rom_decompiled.asm

The optional JSON output is useful for scripts or later analysis:

build/rom_decompiled.json

python h8536_decompiler.py --help

--mode min|max: vector format. This ROM appears to be minimum mode; min is the default.
--entry H'1234: add an extra entry point to recursive tracing.
--linear: linear-sweep the selected range instead of tracing from vectors.
--start H'1000 --end H'D100: constrain the decode range.
--br H'FE: resolve short absolute @aa:8 operands through a known base-register value.

h8536_decompiler.py: compatibility wrapper for the CLI.
h8536/cli.py: argument parsing and end-to-end orchestration.
h8536/decoder.py: instruction and effective-address decoding.
h8536/tables.py: manual-derived opcode/vector/register tables.
h8536/vectors.py: exception vector parsing.
h8536/analysis.py: recursive tracing, linear sweep, and labels.
h8536/render.py: assembly and JSON output.
h8536/model.py, h8536/rom.py, h8536/formatting.py: shared data structures and helpers.