Reverse-engineering notes

OpenCMR2 is ported from the Windows program CMR2.exe (Colin McRae Rally 2.0, Codemasters, 2000; version 1.11). These notes record what is known about it, with exact addresses, so that the port can cite the original function by function.

Page	What
Architecture	Main loop, modes and the process framework, timing, files, rendering, sound, input, network
Inventory	The function map by address range, with the anchor functions of each subsystem
Port plan	The order of the work, with the check that ends each step
File formats	The disc, the containers, models, stages, cars, media

Tools and set-up

• The program. CMR2.exe is not on the disc as a file: extract it from the cabinet with tools/iscab.py cd CMR2.exe cmr2.exe (extract the CD). ./cmr2.exe is the Ghidra copy (git-ignored). tools/exe.py <va> [count] [u32|u16|u8|i32|f32|s] prints values at virtual addresses.

• Ghidra through ghidra-cli: project cmr2, program cmr2.exe.

  ghidra import "$PWD/cmr2.exe" --project cmr2 --program cmr2.exe        # once, with analysis
  tools/ghidra/apply-names.sh                                            # names.tsv -> Ghidra, then the dumps
  ghidra decompile 0x4a9720 --project cmr2 --program cmr2.exe
  ghidra x-ref to 0x4aa220 --project cmr2 --program cmr2.exe

  apply-names.sh runs FillGaps.java (functions the analysis missed), ApplyNames.java (tools/ghidra/names.tsv), then writes re/all.c (every function decompiled, for grepping), re/meta.tsv (address, name, size, callers, callees, imports, strings) and re/funcs.txt. re/ is git-ignored: it is derived from the original.

• Names. tools/ghidra/names.tsv is the record: address, name, module, confidence (high = read and understood, med = from calls and strings, low = guess), description. Rename there, re-run the script.

• Data. tools/bfl.py <file> [outdir] lists or extracts any file of the disc; tools/cmr2fmt.py png|wav|obj <file[:member]> exports a texture, sound or model (obj places a car's parts by their matrices and writes the textures as PNGs; for a stage pass the country's <country>hit.bfl as the texture archive). Decoded data goes to out/ (git-ignored).

Rules for the notes

• Describe layouts, formulas and addresses in your own words. No decompiler output in the notes or the source.
• Mark what is confirmed and what is inferred; give the address that would confirm it.
• Community knowledge (CMR2 modding tools and notes) may help with a format; the exe is the authority and no code is copied.