[SOLVED] Assembly programming on Linux?

turboscrew · 08-09-2013, 06:53 AM

Two questions:

1)
Does anyone know a forum(s) about assembly programming on Linux?
Could be restricted to x86, or non-restricted to Linux.

2)
Why is it that my little assembly program, that uses command line parameters, runs fine if compiled with GCC, but crashes with segmentation fault if compiled wit as and linked with ld?

rtmistler · 08-09-2013, 09:04 AM

No forum that I know of or can find.

The output of that should be machine instructions, so what I'd do is to compare the output from GCC with the output from AS.

mjolnir · 08-09-2013, 09:11 AM

http://board.flatassembler.net/topic.php?t=6365

turboscrew · 08-09-2013, 01:10 PM

Figured the 2) out:
GCC adds a prologue (cinit, I guess) that reorganizes the commandline parameters and calls the "main".
AS doesn't.

Code:

# GCC
# Stack is:
#ESP -> ret addr
#	argc
#	argv -> argv[0] -> "program name"
#		argv[1] -> "Key"
#		argv[2] -> "Infile"
#		argv[3] -> "Outfile"

# GAS
# Stack is:
#ESP -> argc
#	argv[0] -> "program name"
#	argv[1] -> "Key"
#	argv[2] -> "Infile"
#	argv[3] -> "Outfile"