nuclear@47: #include <string.h>
nuclear@42: #include "proc.h"
nuclear@42: #include "tss.h"
nuclear@45: #include "vm.h"
nuclear@47: #include "segm.h"
nuclear@47: #include "intr.h"
nuclear@47: #include "panic.h"
nuclear@47: 
nuclear@47: 
nuclear@47: /* defined in test_proc.S */
nuclear@47: void test_proc(void);
nuclear@47: void test_proc_end(void);
nuclear@42: 
nuclear@42: static struct process proc[MAX_PROC];
nuclear@42: static int cur_pid;
nuclear@42: 
nuclear@42: void init_proc(void)
nuclear@42: {
nuclear@47: 	int proc_size_pg, img_start_pg, stack_pg;
nuclear@45: 	void *img_start;
nuclear@42: 	cur_pid = -1;
nuclear@42: 
nuclear@42: 	/* prepare the first process */
nuclear@42: 
nuclear@42: 	/* allocate a chunk of memory for the process image
nuclear@42: 	 * and copy the code of test_proc there.
nuclear@42: 	 * (should be mapped at a fixed address)
nuclear@42: 	 */
nuclear@49: 	/*proc_size_pg = (test_proc_end - test_proc) / PGSIZE + 1;
nuclear@45: 	if((img_start_pg = pgalloc(proc_size_pg, MEM_USER)) == -1) {
nuclear@45: 		panic("failed to allocate space for the init process image\n");
nuclear@45: 	}
nuclear@45: 	img_start = (void*)PAGE_TO_ADDR(img_start_pg);
nuclear@49: 	memcpy(img_start, test_proc, proc_size_pg * PGSIZE);*/
nuclear@49: 	img_start = test_proc;
nuclear@45: 
nuclear@47: 	/* instruction pointer at the beginning of the process image */
nuclear@47: 	proc[0].ctx.instr_ptr = (uint32_t)img_start;
nuclear@47: 
nuclear@47: 	/* allocate the first page of the process stack */
nuclear@47: 	stack_pg = ADDR_TO_PAGE(KMEM_START) - 1;
nuclear@47: 	if(pgalloc_vrange(stack_pg, 1) == -1) {
nuclear@47: 		panic("failed to allocate user stack page\n");
nuclear@47: 	}
nuclear@47: 	proc[0].ctx.stack_ptr = PAGE_TO_ADDR(stack_pg) + PGSIZE;
nuclear@47: 
nuclear@45: 	/* create the virtual address space for this process */
nuclear@47: 	proc[0].ctx.pgtbl_paddr = clone_vm();
nuclear@45: 
nuclear@47: 	/* we don't need the image and the stack in this address space */
nuclear@49: 	/*unmap_page_range(img_start_pg, proc_size_pg);
nuclear@49: 	pgfree(img_start_pg, proc_size_pg);*/
nuclear@45: 
nuclear@47: 	unmap_page(stack_pg);
nuclear@47: 	pgfree(stack_pg, 1);
nuclear@42: 
nuclear@42: 
nuclear@42: 	/* switch to it by calling a function that takes the context
nuclear@42: 	 * of the current process, plugs the values into the interrupt
nuclear@42: 	 * stack, and calls iret.
nuclear@42: 	 * (should also set ss0/sp0 in TSS before returning)
nuclear@42: 	 */
nuclear@47: 	context_switch(0);
nuclear@47: 	/* XXX this will never return */
nuclear@42: }
nuclear@42: 
nuclear@47: 
nuclear@47: void context_switch(int pid)
nuclear@42: {
nuclear@47: 	struct intr_frame ifrm;
nuclear@47: 	struct context *ctx = &proc[pid].ctx;
nuclear@47: 
nuclear@49: 
nuclear@47: 	cur_pid = pid;
nuclear@47: 
nuclear@47: 	ifrm.inum = ifrm.err = 0;
nuclear@47: 
nuclear@47: 	ifrm.regs = ctx->regs;
nuclear@47: 	ifrm.eflags = ctx->flags;
nuclear@47: 
nuclear@47: 	ifrm.eip = ctx->instr_ptr;
nuclear@49: 	ifrm.cs = selector(SEGM_KCODE, 0);	/* XXX change this when we setup the TSS */
nuclear@49: 	ifrm.esp = 0;/*ctx->stack_ptr;			/* this will only be used when we switch to userspace */
nuclear@49: 	ifrm.regs.esp = ctx->stack_ptr;		/* ... until then... */
nuclear@49: 	ifrm.ss = 0;/*selector(SEGM_KDATA, 0);	/* XXX */
nuclear@47: 
nuclear@47: 	/* switch to the vm of the process */
nuclear@47: 	set_pgdir_addr(ctx->pgtbl_paddr);
nuclear@47: 
nuclear@47: 	intr_ret(ifrm);
nuclear@47: }