From eb1ad3fd11a26d7a2cc124454e40790ed386d7ff Mon Sep 17 00:00:00 2001 From: Dylan Lloyd Date: Wed, 17 Oct 2012 01:15:24 -0400 Subject: [PATCH] added macro and function def/call to x32 --- hello32.asm | 48 ++++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/hello32.asm b/hello32.asm index b6178a0..58304db 100644 --- a/hello32.asm +++ b/hello32.asm @@ -1,27 +1,39 @@ +%macro print 2 ; Declare a macro to print a string, with two arguments + mov eax,4 ; Put magic # for system call sys_write into rax + mov edi,1 ; Prepare arg 1 of sys_write, 1 - file descriptor of stdo + mov esi,%1 ; Prepare arg 2, a string reference + mov edx,%2 ; Prepare arg 3, string length, no deref. b/c constant + int 80h ; Call the kernel +%endmacro + section .data - hello: db 'Hello, world.',10 ; declare initialized string with linefeed char - helloLen: equ $-hello ; declare and init. constant - done: db 0 + hello: db 'Hello, world.',10 ; declare initialized string with linefeed char + helloLen: equ $-hello ; declare and init. constant + done: db 0 section .text - global _start + global _start ; Declare program entry point + +_print: + push ebp ; Prologue, save stack pointer + mov ebp,esp ; Get base pointer (start of arguments) + mov ebx,[ebp+8] ; Get first argument (offset from base by the return address) + print ebx,helloLen ; Macro, replaced inline + leave ; Epilogue, equivalent to mov esp,ebp; pop ebp + ret ; Return control to caller _start: - movzx eax, byte [done] ; Pad value of done to one byte and put in eax - cmp eax,1 ; Compare eax with 1 - jg myFirstASMLabel ; Jump if greater than to myFirstASMLabel - - mov byte [done], 1 - - mov eax,4 ; Put magic # for system call sys_write into eax - mov ebx,1 ; Prepare arg 1 of sys_write, 1 - file descriptor of stdo - mov ecx,hello ; Prepare arg 2, reference to string hello - mov edx,helloLen ; Prepare arg 3, string length, no deref. b/c constant - int 80h ; Call the kernel -; + cmp byte [done],1 ; Compare byte padded value of done with 1 + jg exit ; Jump if greater than to exit -myFirstASMLabel: + mov byte [done], 1 ; Put 1 in done + + push hello ; Push the last argument of _print onto the stack + call _print ; Call the function _print + +exit: mov eax,1 ; The system call for exit (sys_exit) - mov ebx,0 ; Exit with return code of 0 (no error) + mov edi,0 ; Exit with return code of 0 (no error) int 80h + -- 2.30.2