From d8331335ff1720ce28eba45afe1a02814b38b033 Mon Sep 17 00:00:00 2001 From: Michal Idziorek Date: Mon, 1 Dec 2014 21:49:22 +0100 Subject: finally implemented fork() syscall --- asm/int_syscall_handler.asm | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'asm/int_syscall_handler.asm') diff --git a/asm/int_syscall_handler.asm b/asm/int_syscall_handler.asm index 50202d3..89f152b 100644 --- a/asm/int_syscall_handler.asm +++ b/asm/int_syscall_handler.asm @@ -1,4 +1,5 @@ global int_syscall_handler +[extern task_fork] [extern syscall_exit] [extern syscall_write] @@ -13,11 +14,18 @@ global int_syscall_handler [extern syscall_sbrk] [extern syscall_stat] [extern syscall_lstat] +[extern syscall_fork] [extern syscall_unhandled] [bits 32] + +pid: dd 0x0 + int_syscall_handler: +cmp eax, 72 +je call_fork + cli push ebx @@ -63,6 +71,7 @@ int_syscall_handler: cmp eax, 79 je call_lstat + push eax jmp call_unhandled @@ -89,6 +98,34 @@ done_blocking: iret ;Interrupt-Return +call_fork: + + cli + + pusha ;Push all standard registers + + mov ebx, esp ;save current stack pointer in esp + mov esp, 0x7000 ;now put the stack outside of virtual memory in kernel space! + + push ebx ;Push pointer to all the stuff we just pushed + call task_fork ;Call C code + mov [pid],eax + + mov esp, ebx ;Replace the stack with what the C code gave us + + mov al, 0x20 ;Port number AND command number to Acknowledge IRQ + out 0x20, al ;Acknowledge IRQ, so we keep getting interrupts + + + popa ;Put the standard registers back + + mov ebx,[pid] + + sti + + iretd ;Interrupt-Return + ;;;; + call_stat: call syscall_stat jmp done @@ -139,6 +176,7 @@ call_unhandled: ;;; THIS CALLS NEED REENABLE INTERRUPTS BEFORE calling workers + ;; TODO: redesign this shit! call_read: mov al, 0x20 ;Port number AND command number to Acknowledge IRQ -- cgit v1.2.3