syscalls look like in i386, the second way is by use syscall, but then
syscall_numbers are different as by int 80h

mov r9,param6
mov r8,param5
mov r10,param4
mov rdx,param3
mov rsi,param2
mov rdi,param1
mov eax,sys_call_number
syscall

e.g. exit is:
mov edi,5	; exit code
mov eax,60	; sys_exit
syscall

or the old in 32-bit:
mov ebx,5
mov eax,1	; sys_exit
int 80h
