void init_task(struct Task_t *t, uint16_t cs, uint16_t ds, uint16_t ss)
{
memset(t, 0, sizeof(struct Task_t));
uint32_t page_dir_pn = alloc_phy_page(0, 1023);
uint32_t stack;
t->block_event = NONBLOCKED;
t->page_dir = (uint32_t *)(page_dir_pn << 12);
if(CURRENT_TASK)
t->ppid = CURRENT_TASK->pid;
else
t->ppid = 7;
map_kernel_page(page_dir_pn, page_dir_pn, true, false, true);
memset(t->page_dir, 0, 4096);
t->page_dir[0] = PAGE_DIR[0];
t->block_event = 0;
t->next = NULL;
t->status = READY;
t->tss.cr3 = (uint32_t)t->page_dir;
t->tss.eflags = 0x202;
t->tss.cs = cs;
t->tss.ds = ds;
t->tss.es = ds;
t->tss.fs = ds;
t->tss.gs = ds;
t->tss.ss = ss;
t->sem_list_size = 0;
t->sigint_handler = sigint_default;
stack = alloc_phy_page(1024, max_page_num);
map_page(t->page_dir, (0xFFFFFFFF - 4096 + 1) >> 12, stack, false, true, true);
t->tss.esp = 0xFFFFFFFF;
}
void *alloc_vm_stack(ulong size)
{
ulong phsize = 0;
ulong addr;
DEBUG_PRINT("Alloc vm stack:%lx\n", size);
void *p = alloc_linear(size + PAGE_SIZE); //one more page
if (!p)
return p;
addr = (ulong) p + PAGE_SIZE; //the lowest page is reserved for stack overflow check
while (phsize <= size) {
ulong pg = alloc_phy_page();
if (!pg) {
if (phsize) {
free_vm_page(addr, phsize);
free_linear(addr, size);
}
return (void *)0;
}
map_page_p2v_rw(pg, addr);
addr += PAGE_SIZE;
phsize += PAGE_SIZE;
}
return (void *)((ulong) p + PAGE_SIZE);
}
void map_page(uint32_t *page_dir, uint32_t virt_page_num, uint32_t phy_page_num,
bool global, bool user, bool read_write)
{
uint16_t pd_idx = PD_IDX(virt_page_num),
pt_idx = PT_IDX(virt_page_num);
uint32_t *page_table;
if(!(page_dir[pd_idx] & 0x1)) {
uint32_t pt_page_num = alloc_phy_page(0, 1023);
map_kernel_page(pt_page_num, pt_page_num, true, false, true);
memset((void *)(pt_page_num << 12), 0, 4096);
page_dir[pd_idx] = make_pde(pt_page_num, user, read_write);
}
page_table = (uint32_t *)(page_dir[pd_idx] & 0xfffff000);
page_table[pt_idx] = make_pte(phy_page_num, global, user, read_write);
++phy_mem_rc[phy_page_num];
__asm__ volatile(
".intel_syntax noprefix;"
"mov eax, cr3;"
"mov cr3, eax;"
".att_syntax;"
:::"eax"
);
}
void *alloc_vm(ulong size)
{
ulong phsize = 0;
ulong addr;
DEBUG_PRINT("Alloc vm:%lx\n", size);
void *p = alloc_linear(size);
if (!p)
return p;
addr = (ulong) p;
while (phsize <= size) {
ulong pg = alloc_phy_page();
if (!pg) {
if (phsize) {
free_vm_page(addr, phsize);
free_linear(addr, size);
}
return (void *)0;
}
map_page_p2v_rw(pg, addr);
addr += PAGE_SIZE;
phsize += PAGE_SIZE;
}
return p;
}
