Ghidra is nice!

[ilmenit]

Hi,

 

I recently had some time to test Ghidra (reverse engineering tool released by NSA) and it is great free alternative to IDA Pro or Dis6502.

https://github.com/NationalSecurityAgency/ghidra

It has 6502 support and easily (with skipping header and setting loading address) you can load single segment XEX files. I didn't check yet how to script it for multi-segment XEX. It shouldn't be hard to create an Atari loader basing on https://github.com/zeroKilo/C64LoaderWV

 

Then you can analyze the code in very convenient way, with even translation of ASM to C language.

I didn't check (yet) https://github.com/tom-seddon/Ghidra6502

 

Simple keyboard manual (how to rename labels, set arrays, start code analysis) is here: 

https://ghidra-sre.org/CheatSheet.html

 

 

Edited August 26, 2021 by ilmenit

[Rybags]

Cool - will have to give it a look.

 

An alternative to trying to stick multiple segments together can be to just use a memory dump from emulation.

But generally you want to set the trap to very early on so you get it before the program has a chance to make any modifications to itself or it's data areas.

[ilmenit]

3 minutes ago, Rybags said:

Cool - will have to give it a look.

 

An alternative to trying to stick multiple segments together can be to just use a memory dump from emulation.

But generally you want to set the trap to very early on so you get it before the program has a chance to make any modifications to itself or it's data areas.

yup, breakpoint on the RUN address in majority of cases should be enough

[ggn]

Ghidra is indeed very nice. It's not without its faults: for example I still haven't found an option that can export a disassembly that you can then immediately reassemble. Some processing of the file is required. Also, marking bytes as an array (so you can make the source more compact) is still quite weird.

 

But still, it helped me a lot in disassembling a game and porting it to the Atari ST, and is much better than similar free tools (radare2, cutter) and costs way less than commercial tools (IDA pro, Binary Ninja). So definitely worth checking out!

 

 

[Kyle22]

Toolkits can be helpful.

https://qagg.news/?q=ghidra

K