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I found some helpful thoughts regarding GAS - agreed, for source distributions targeting Linux is has a place, but it's not really a full blown macro assembler.

I found some helpful thoughts regarding GAS - agreed, for source distributions targeting Linux is has a place, but it's not really a full blown macro assembler. Using the C preprocessor seems like a poor hack to me. Although I haven't tried it, it's generally discouraged in C, never mind something it was never intended for. Also, AT&T syntax: Yuck! http://x86asm.net/articles/what-i-dislike-about-gas/ http://x86asm.net/articles/what-i-dislike-about-gas/

MegaDeKay 12y ago
You don't have to use AT&T syntax in GAS. I wrote a blog post a while back showing how you can use Intel syntax instead, and skip a whole lot of % characters while you are at it. http://madscientistlabs.blogspot.ca/2013/07/gas-problems.html http://madscientistlabs.blogspot.ca/2013/07/gas-problems.htm...
- e12e 12y ago
  Wow, thanks for that! It's still a little painful, but here goes: # file:hello.s # # Translated to gas syntax. # assemble with: # as --64 -o hello.o hello.s # link with: # ld -o hellos hellos.o # # Modifications to original code considered trivial and to be # public domain. # # Support intel syntal vs. ATT and don't use % before register names .intel_syntax noprefix .section .data msg: .asciz "hello, world!\n" .section .text .global _start _start: # write syscal mov rax, 1 # file descritor, standard output mov rdi, 1 # message address mov rsi, OFFSET FLAT:msg # length of message mov rdx, 14 # call write syscall syscall # mov rax, 60 mov rdi, 0 syscall Note the trailing new-line in the message (and length change from 13 to 14). For nasm: section .data msg db "hello, world!",`\n` ;; Remember to use 14 for string length!
  - MegaDeKay 12y ago
    Try these changes instead. Untested, but it should work # String is read only. .section .rodata msg: .asciz "hello, world!\n" # Put string length in a variable instead .set STR_SIZE, . - msg # <snip> mov rdx, STR_SIZE

MegaDeKay 12y ago

You don't have to use AT&T syntax in GAS. I wrote a blog post a while back showing how you can use Intel syntax instead, and skip a whole lot of % characters while you are at it. http://madscientistlabs.blogspot.ca/2013/07/gas-problems.html http://madscientistlabs.blogspot.ca/2013/07/gas-problems.htm...

e12e 12y ago
Wow, thanks for that! It's still a little painful, but here goes: # file:hello.s # # Translated to gas syntax. # assemble with: # as --64 -o hello.o hello.s # link with: # ld -o hellos hellos.o # # Modifications to original code considered trivial and to be # public domain. # # Support intel syntal vs. ATT and don't use % before register names .intel_syntax noprefix .section .data msg: .asciz "hello, world!\n" .section .text .global _start _start: # write syscal mov rax, 1 # file descritor, standard output mov rdi, 1 # message address mov rsi, OFFSET FLAT:msg # length of message mov rdx, 14 # call write syscall syscall # mov rax, 60 mov rdi, 0 syscall Note the trailing new-line in the message (and length change from 13 to 14). For nasm: section .data msg db "hello, world!",`\n` ;; Remember to use 14 for string length!
- MegaDeKay 12y ago
  Try these changes instead. Untested, but it should work # String is read only. .section .rodata msg: .asciz "hello, world!\n" # Put string length in a variable instead .set STR_SIZE, . - msg # <snip> mov rdx, STR_SIZE