64 bit windows assembler debugging

Question

I am trying to debug some assembler code on windows. For 32 bit code I was using Ollydbg, but it is unable to open 64-bit exe files.

I also tried using the visual studio debugger but I think the stack is somehow getting corrupted and I can't figure out how to place a breakpoint at the program entry, so this doesn't work

So are there any free programs that work?

If it matters I am using nasm and then gcc to compile the exe's

Whatever usefulness this topic has I needed a debugger too. So randomly I've found some: [FDBG](http://fdbg.x86asm.net/), [Visual DuxDebugger](http://www.duxcore.com/index.php/prod/visual-duxdebugger/overview) and [PEbrowseDbg64](http://www.smidgeonsoft.prohosting.com/pebrowse-pro-interactive-debugger.html). Though not one of them is as good as ollydbg. — DitherSky, Aug 01 '13 at 10:19

score 2 · Answer 1 · answered Jun 20 '11 at 12:44

2

why not give windbg a try, its made by MS and free, here's the 64bit version.

answered Jun 20 '11 at 12:44

Necrolis

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well I tried that and couldn't get it to work, I ended up soving the problem by comparing the output to a valid c program using objdump -d – John Palmer Jun 22 '11 at 01:43
@jpalmer: What part wasn't working? – Necrolis Jun 22 '11 at 05:23
@jpalmer: you may find this of use if your having problems: http://www.nynaeve.net/?p=8 – Necrolis Jun 22 '11 at 05:45
Unfortunately, 64bit windbg does not support write 64-bit assembly by "a" command. – zhaorufei Oct 10 '13 at 13:35

score 1 · Answer 2 · answered Jul 26 '11 at 15:05

Visual studion has an excellent debugger for both 32 bit and 64 bit windows. If you are using nasm or yasm assembler then use the option -gcv8 on the assembler. This produces debug info that works with visual studio. You have to make a project in VS that includes both C/C++ and asm files. The asm files need a custom build rule looking something like: CommandLine="yasm -fwin64 -gcv8 -o$(InputName).obj [inputs]" Outputs="$(InputName).obj"

64 bit windows assembler debugging

2 Answers2