GNU >> Assembly (x64)
hello, world! (syscall)
參考資訊：
1. syscall
2. how-to-use-sysenter-under-linux
main.s
.global _start
.data
msg: .ascii "hello, world!\n"
len = . - msg
.text
_start:
mov $1, %rax
mov $1, %rdi
mov $msg, %rsi
mov $len, %rdx
syscall
mov $60, %rax
xor %rdi, %rdi
syscall
| NR | syscall name | rax | arg0(rdi) | arg1(rsi) | arg2(rdx) |
|---|---|---|---|---|---|
| 1 | write | 1 | unsigned int fd | const char *buf | size_t count |
| 60 | exit | 60 | int error_code |
編譯、執行
$ x86_64-linux-gnu-gcc main.s -o main -static -nostdlib
$ qemu-x86_64 ./main
hello, world!