[bits 32]
; Clear registers
xor ebx, ebx
mul ebx

; Prepare registers to call sys_write
mov al, 4
mov dl, 13
; Push null terminated string 'hello, world\n'
push ebx
push byte `\n`
push `orld`
push `o, w`
push `hell`
; To write to stdout, uncomment line below.
; Otherwise output is written to stdin.
; This still prints, as the file descriptors appear to share a buffer.
; Omitting this increment saves us 1 byte.
;inc ebx
; Set ecx to &string and call sys_write
mov ecx, esp
int 0x80

; Clear edx, set eax to call sys_execve
cdq
mov al, 0xb

; Push null terminated string '-u' and set ecx to its address.
push edx
push word `-u`
mov ecx, esp
; Push *argv[] to the stack. argv[0] is just '-u' now, as it's not used.
push edx
push ecx
push ecx
mov ecx, esp

; Push path to bin to the stack and make ebx point to it
push edx
push `//id`
push `/bin`
push `/usr`
mov ebx, esp

; Call sys_execve
int 0x80