12 May
2025
12 May
'25
7 a.m.
Hello everyone,
I'm working on building a decompiler from PDP-11 assembly to C to ease studying
old pre-C Unix sources. To start, I'm translating V5 `as` to period-idiomatic C
and have finished most of pass 1. Then I'll port it to Rust with a design better
suited to static analysis, while keeping exact fidelity to the original. I'll
do the same for `cc` and `ld`, after.
I stumbled upon Warren's disaout[0] today, which made me wonder:
What tools have people for reverse engineering Unix assembly sources or a.out
binaries? Things like disassemblers or decompilers.
I assume there's some versions of programs which are now only extant as
binaries? Are there enough such binaries that were written in C to warrant
writing a decompiler that understands the specific codegen of `cc` to improve
accuracy? For now, I'm focusing on decompiling hand-written assembly, but I'm
keeping this case in mind.
Thanks!
Thalia
[0]: https://github.com/DoctorWkt/unix-jun72/tree/master/tools/disaout