BFM-decomp/cookbook/C0412.md

§371 ★★ — CARVING A SINGLE-OBJECT MODULE BINARY, AND THE spimdisasm RODATA-MIGRATION TRAP THAT FOLLOWS (P31 S68; byte-proven md_MAIN_003, func_800D0D6C 345 ins)

The overlays arrive pre-split into many jr_* objects; the md_* module binaries are ONE c subseg. Every attempt to carve an -O0 range out of one died at jr_isolate_all: unaddressable content. That single message was three stacked causes, which is exactly why it read as one impassable wall — fix one and the message does not change:

1. overlay_src_split.load_ov_syms stopped at an interior YAML comment. md_MAIN_003's yaml annotates the body of its symbol-file list, so only symbols.us.txt loaded and D_800D3200 resolved to None.
2. A trailing content chunk had nowhere to go. The verbatim-asm pair after the last addressable anchor now attaches to the LAST region when every symbol it defines resolves at/after the last cut, instead of hard-refusing.
3. Bare tag forward decls (struct S_D2394;) tripped the _file_scope_decls dedupe refusal.

THEN THE CARVE CAUSES A LINK FAILURE, and this is the reusable part. spimdisasm migrates rodata referenced by exactly one function into that function's .s ONLY within the same subseg. A carve that moves the function to a new subseg while the .rodata island stays behind makes splat silently drop those blocks:

undefined reference to `D_800CEE58' / `D_800CEE80'   (from the post object's .text)

INCLUDE_RODATA does NOT resurrect them — splat marks them migrated segment-wide and emits nothing (can't open ... D_800CEE58.s). The fix is to rename the .rodata subseg to the object where its emitters now live. Verification that you got it right: the regenerated .s for the moved function comes back byte-identical to the pre-carve one.

THE MAKEFILE HUNK IS PART OF THE CARVE, NOT A FOLLOW-UP. The -O0 wildcard covered only src/ov_*/ov_*_o0?.c. A module region file compiles at -O2 without widening it to src/md_*/md_*_o0?.c — byte-neutral while the region holds only stubs (INCLUDE_ASM is verbatim asm), but every -O0 draft banked into it then mystery-fails the gate (§362's trap class), and a fresh clone reintroduces it. Commit the Makefile, the tool fixes and the carve TOGETHER.

DO NOT chase interleave_check ALIGNED here. md_MAIN_003 reports DRIFT on a CLEAN tree — pre-existing, not carve-caused (verify before changing anything). It has no _JTBL_INTERLEAVE block and must not get one: forcing ALIGNED moves the leading rodata island after .text and shifts every address by 0xD8. The honest criterion is "the carve does not change interleave_check's output".

KNOWN, STILL OPEN: a second carve on the same binary now refuses with jr_inventory(md_MAIN_003): committed .rodata carve ownership is not 1:1 (R32/R33) — a stranded/duplicated carve: [('UNOWNED', '0x800cedf8')]. The first carve's rodata rename left that island unowned by the inventory's 1:1 check. Solve that before carving the remaining 7 -O0 stubs in this binary's pre-TU.

PLANNING THE REST (§126 applied): of md_MAIN_003's 12 open stubs, 8 are -O0 (1,166 ins). func_800D0A7C / func_800D0B1C / func_800D0C50 are ADJACENT (gap 0) so ONE region covers all three; the other five have matched bodies between them and need their own regions — K interleaved matched bodies ⇒ K+1 regions, which o0_subsplit derives for you from a single --lo/--hi span.