Netwide Assembler (NASM) >> Assembly (x86)
hello, world! (gs)
參考資訊：
1. syscall
2. how-to-use-sysenter-under-linux
3. what-does-gs0x10-do-in-assembler
System Call
| NR | syscall name | eax | arg0(ebx) | arg1(ecx) | arg2(edx) |
|---|---|---|---|---|---|
| 1 | exit | 1 | int error_code | ||
| 4 | write | 4 | unsigned int fd | const char *buf | size_t count |
main.s
global main
section .data
msg db "hello, world!", 10
len equ $ - msg
section .text
main:
mov eax, 4
mov ebx, 1
mov ecx, msg
mov edx, len
call [gs:0x10]
mov eax, 1
mov ebx, 0
call [gs:0x10]
編譯、執行
$ nasm -f elf32 main.s
$ i686-linux-gnu-gcc main.o -o main -static
$ qemu-i386 ./main
hello, world!