nuclear@52: #include <stdio.h>
nuclear@47: #include <string.h>
nuclear@52: #include <assert.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@51: #include "syscall.h"
nuclear@51: #include "sched.h"
nuclear@47: 
nuclear@52: #define	FLAGS_INTR_BIT	9
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@51: 	cur_pid = 0;
nuclear@51: 
nuclear@51: 	init_syscall();
nuclear@42: 
nuclear@42: 	/* prepare the first process */
nuclear@51: 	proc[1].id = 1;
nuclear@51: 	proc[1].parent = 0;
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@51: 	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@51: 	memcpy(img_start, test_proc, proc_size_pg * PGSIZE);
nuclear@45: 
nuclear@52: 	printf("copied init process at: %x\n", (unsigned int)img_start);
nuclear@52: 
nuclear@47: 	/* instruction pointer at the beginning of the process image */
nuclear@51: 	proc[1].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@51: 	proc[1].ctx.stack_ptr = PAGE_TO_ADDR(stack_pg) + PGSIZE;
nuclear@47: 
nuclear@52: 	proc[1].stack_end = KMEM_START;
nuclear@52: 	proc[1].stack_start = KMEM_START - PGSIZE;
nuclear@52: 
nuclear@45: 	/* create the virtual address space for this process */
nuclear@51: 	proc[1].ctx.pgtbl_paddr = clone_vm();
nuclear@45: 
nuclear@47: 	/* we don't need the image and the stack in this address space */
nuclear@51: 	unmap_page_range(img_start_pg, proc_size_pg);
nuclear@51: 	pgfree(img_start_pg, proc_size_pg);
nuclear@45: 
nuclear@47: 	unmap_page(stack_pg);
nuclear@47: 	pgfree(stack_pg, 1);
nuclear@42: 
nuclear@51: 	/* add it to the scheduler queues */
nuclear@52: 	add_proc(1, STATE_RUNNING);
nuclear@42: 
nuclear@51: 	/* switch to the initial process, this never returns */
nuclear@51: 	context_switch(1);
nuclear@42: }
nuclear@42: 
nuclear@47: 
nuclear@47: void context_switch(int pid)
nuclear@42: {
nuclear@52: 	struct context *ctx;
nuclear@47: 	struct intr_frame ifrm;
nuclear@52: 	struct intr_frame *cur_frame = get_intr_frame();
nuclear@47: 
nuclear@52: 	assert(0);
nuclear@49: 
nuclear@52: 	if(cur_pid == pid) {
nuclear@52: 		assert(cur_frame);
nuclear@52: 		intr_ret(*cur_frame);
nuclear@52: 	}
nuclear@52: 
nuclear@52: 	ctx = &proc[pid].ctx;
nuclear@47: 	cur_pid = pid;
nuclear@47: 
nuclear@47: 	ifrm.inum = ifrm.err = 0;
nuclear@47: 
nuclear@47: 	ifrm.regs = ctx->regs;
nuclear@52: 	ifrm.eflags = ctx->flags | (1 << FLAGS_INTR_BIT);
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@52: 	/*ifrm.regs.esp = ctx->stack_ptr;*/		/* ... until then... */
nuclear@52: 	ifrm.esp = ctx->stack_ptr;			/* this will only be used when we switch to userspace */
nuclear@52: 	ifrm.ss = selector(SEGM_KDATA, 0);
nuclear@47: 
nuclear@47: 	/* switch to the vm of the process */
nuclear@47: 	set_pgdir_addr(ctx->pgtbl_paddr);
nuclear@47: 	intr_ret(ifrm);
nuclear@47: }
nuclear@51: 
nuclear@51: int get_current_pid(void)
nuclear@51: {
nuclear@51: 	return cur_pid;
nuclear@51: }
nuclear@51: 
nuclear@51: struct process *get_current_proc(void)
nuclear@51: {
nuclear@51: 	return cur_pid ? &proc[cur_pid] : 0;
nuclear@51: }
nuclear@51: 
nuclear@51: struct process *get_process(int pid)
nuclear@51: {
nuclear@51: 	return &proc[pid];
nuclear@51: }