kern: src/proc.c annotate

kern

started implementing processes

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sun, 24 Jul 2011 18:29:24 +0300
parents
children	5f6c5751ae05

rev	line source
nuclear@42	1 #include "proc.h"
nuclear@42	2 #include "tss.h"
nuclear@42	3
nuclear@42	4 static struct process proc[MAX_PROC];
nuclear@42	5 static int cur_pid;
nuclear@42	6
nuclear@42	7 void init_proc(void)
nuclear@42	8 {
nuclear@42	9 cur_pid = -1;
nuclear@42	10
nuclear@42	11 /* prepare the first process */
nuclear@42	12
nuclear@42	13 /* create the virtual address space for this process */
nuclear@42	14
nuclear@42	15 /* allocate a chunk of memory for the process image
nuclear@42	16 * and copy the code of test_proc there.
nuclear@42	17 * (should be mapped at a fixed address)
nuclear@42	18 */
nuclear@42	19
nuclear@42	20 /* fill in the proc[0].ctx with the appropriate process stack
nuclear@42	21 * and instruction pointers
nuclear@42	22 */
nuclear@42	23
nuclear@42	24 /* switch to it by calling a function that takes the context
nuclear@42	25 * of the current process, plugs the values into the interrupt
nuclear@42	26 * stack, and calls iret.
nuclear@42	27 * (should also set ss0/sp0 in TSS before returning)
nuclear@42	28 */
nuclear@42	29 }
nuclear@42	30
nuclear@42	31 void save_context(struct intr_frame *ifrm)
nuclear@42	32 {
nuclear@42	33 proc[cur_pid].ctx->regs = ifrm->regs;
nuclear@42	34 proc[cur_pid].ctx->instr_ptr = ifrm->eip;
nuclear@42	35 proc[cur_pid].ctx->stack_ptr = ifrm->esp;
nuclear@42	36 proc[cur_pid].ctx->flags = ifrm->eflags;
nuclear@42	37 }