Hi,
I'm doing some ASM code in a C code with the asm function.
My environment is DVL with gcc version 3.
Hi need to make a JMP to a relative address like %eip+0x1f.
How can I do this ?
Thanks
+2
A:
x86 supports a short jump (JMP, opcode EB + 1 byte relative address) which should do what you want.
In most assemblers (including gcc's inline asm IIRC) you can just put a label where you want to jump to, and use jmp mylabel and let the assember figure out the correct opcode and relative address for the jump.
Charles Bailey
2010-03-21 23:00:09
I've just tried this out in GCC, and it does work (jumping to labels). But you beat me to the post!
Michael Williamson
2010-03-21 23:05:00
A:
Are you using inline ASM? In gcc, using + in inline asm is illegal. Also, that syntax looks wrong to me.
Do some digging to look up the proper syntas for AT&T assembly. Which is what GNU uses.
Edit: Unless, of course, you'd rather use labels :)
David Titarenco
2010-03-21 23:03:36