global int_syscall_handler

[extern syscall_write]
[extern syscall_read]
[extern syscall_readdir]
[extern syscall_execve]

[bits 32]
int_syscall_handler:

 cli

    push ebx
    push ecx
    push edx

    cmp eax, 61
    je call_write

    cmp eax, 62
    je call_read

    cmp eax, 63
    je call_readdir

    cmp eax, 64
    je call_execve

done:

    mov ebx,eax 

    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
    out 0x20, al     ;Acknowledge IRQ, so we keep getting interrupts

    mov eax,ebx 
    nop


done_blocking:

    pop ebx
    pop ecx
    pop edx

    mov ebx,eax 

    sti

    iret           ;Interrupt-Return

call_write:
    call syscall_write
    jmp done

call_readdir:
    call syscall_readdir
    jmp done

call_read:
    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
    out 0x20, al     ;Acknowledge IRQ, so we keep getting interrupts
    sti

    call syscall_read

    jmp done_blocking

call_execve:
    mov al, 0x20   ;Port number AND command number to Acknowledge IRQ
    out 0x20, al     ;Acknowledge IRQ, so we keep getting interrupts
    sti
    call syscall_execve
    jmp $ ; this should never return TODO: pop stack!?