void restart()
{
/* Perform some initialization to restart a program */
memcpy(hwa_to_va(LOADER_START), loader, loader_len);
tlb_init();
/* General initialization */
cpu.eip = LOADER_START;
cpu.ebp = 0;
cpu.esp = 0x8000000;
cpu.eflags = 0x2;
cpu.eax = 0;
cpu.ecx = 0;
cpu.edx = 0;
cpu.cr0.paging = 0;
cpu.cr0.protect_enable = 0;
cpu.INTR = 0;
FLAG_CHG(IF, 0);
/* Segment initialization */
cpu.gdtr.limit = 0;
cpu.gdtr.base = 0;
cpu.cr[0] = 0; // Set PE to 0
load_prog();
// trigger = TRIGGER_INIT;
init_dram();
}
static void load_entry() {
int ret;
FILE *fp = fopen("entry", "rb");
Assert(fp, "Can not open 'entry'");
fseek(fp, 0, SEEK_END);
size_t file_size = ftell(fp);
fseek(fp, 0, SEEK_SET);
ret = fread(hwa_to_va(ENTRY_START), file_size, 1, fp);
assert(ret == 1);
fclose(fp);
}
static void init_ramdisk() {
int ret;
const int ramdisk_max_size = 0xa0000;
FILE *fp = fopen(exec_file, "rb");
Assert(fp, "Can not open '%s'", exec_file);
fseek(fp, 0, SEEK_END);
size_t file_size = ftell(fp);
Assert(file_size < ramdisk_max_size, "file size(%zd) too large", file_size);
fseek(fp, 0, SEEK_SET);
ret = fread(hwa_to_va(0), file_size, 1, fp);
assert(ret == 1);
fclose(fp);
}
void load_prog() {
struct stat st;
stat(exec_file, &st);
assert(st.st_size < 0xa0000);
FILE *fp = fopen(exec_file, "rb");
assert(fp);
/* We do not have a virtual hard disk now. Before we have a virutal hard disk,
* the beginning of physical memory is used as a "disk". The loader in NEMU
* will load the program from this "disk" (at the beginning of the physical
* memory).
*/
fread(hwa_to_va(0), st.st_size, 1, fp);
fclose(fp);
}
void bmr_io_handler(ioaddr_t addr, size_t len, bool is_write) {
int ret;
if(is_write) {
if(addr - BMR_PORT == 0) {
if(bmr_base[0] & 0x1) {
/* DMA start command */
if(bmr_base[0] & 0x8) {
/* DMA read */
/* the address of Physical Region Descriptor Table */
hwaddr_t prdt_addr = *(uint32_t *)(bmr_base + 4);
hwaddr_t addr = hwaddr_read(prdt_addr, 4);
uint32_t hi_entry = hwaddr_read(prdt_addr + 4, 4);
uint16_t byte_cnt = hi_entry & 0xffff;
sector = (ide_port_base[6] & 0x1f) << 24 | ide_port_base[5] << 16
| ide_port_base[4] << 8 | ide_port_base[3];
disk_idx = sector << 9;
fseek(disk_fp, disk_idx, SEEK_SET);
ret = fread((void *)hwa_to_va(addr), byte_cnt, 1, disk_fp);
assert(ret == 1|| feof(disk_fp));
/* We only implement PRDT of single entry. */
assert(hi_entry & 0x80000000);
/* finish */
ide_port_base[7] = 0x40;
i8259_raise_intr(IDE_IRQ);
}
else {
/* DMA write is not implemented */
assert(0);
}
}
}
}
}
void restart() {
/* Perform some initialization to restart a program */
load_prog();
memcpy(hwa_to_va(LOADER_START), loader, loader_len);
cpu.eip = LOADER_START;
cpu.ebp = 0;
cpu.esp = 0x8000000;
cpu.eflags = 2;
init_dram();
init_cache1();
init_cache2();
init_TLB();
/* initialize limit of cs in gdt */
// printf("%x\n",cpu.gdtr.base);
// uint16_t *cs_limit =(void *)(0x90901700 + 64);
// *cs_limit = 0xffff;
seg_cache[1].limit = 0xffffffff;//can't modify memory in 0x90901700
// *cs_limit = 0xffff;//other bits are initialized by 0
}
