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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/PROJECTS.md | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/docs/PROJECTS.md b/docs/PROJECTS.md index 38d3262..eae860b 100644 --- a/docs/PROJECTS.md +++ b/docs/PROJECTS.md @@ -317,6 +317,24 @@ ARM32. `t` again toggles back — the mode is a guess, and guesses get revised. Both states are saved in the `.i64`. +**Pick a 32-bit processor at load, or none of this decompiles.** Bare `arm` +gives a 64-BIT database (AArch64), and that is decided at load time and cannot be +changed afterwards — setting the bitness post-hoc makes the decompiler INTERR. +In a 64-bit database: + +* Thumb doesn't exist, so `t` sets a segment flag that means nothing; and +* Hex-Rays refuses a 32-bit function outright — *"only 64-bit functions can be + decompiled in the current database"* — so the disassembly looks right and F5 + silently produces nothing. + +So the list offers `arm:ARMv7-A` (most firmware), `arm:ARMv7-M` / `arm:ARMv6-M` +(Cortex-M, Thumb only) and `arm:ARMv5TE` alongside 64-bit `arm`. `t` warns when +it notices the database is 64-bit and points at `Ctrl+L`. + +Worth knowing: a correctly-chosen 32-bit ARM database also lets IDA's own +auto-analysis find Thumb functions — `experiments/fibonacci.bin` yields 54 +functions on load with `arm:ARMv7-A` and none with `arm`. + ### When analysis finds nothing Zero functions is what a raw image described wrongly looks like — right file, |