void init_desc(void)
{
// IDT entries
ISR_ENTRY(0); ISR_ENTRY(1); ISR_ENTRY(2); ISR_ENTRY(3); ISR_ENTRY(4); ISR_ENTRY(5);
ISR_ENTRY(6); ISR_ENTRY(7); ISR_ENTRY(8); ISR_ENTRY(9); ISR_ENTRY(10); ISR_ENTRY(11);
ISR_ENTRY(12); ISR_ENTRY(13); ISR_ENTRY(14); ISR_ENTRY(15); ISR_ENTRY(16); ISR_ENTRY(17);
ISR_ENTRY(18); ISR_ENTRY(19); ISR_ENTRY(20); ISR_ENTRY(21); ISR_ENTRY(22); ISR_ENTRY(23);
ISR_ENTRY(24); ISR_ENTRY(25); ISR_ENTRY(26); ISR_ENTRY(27); ISR_ENTRY(28); ISR_ENTRY(29);
ISR_ENTRY(30); ISR_ENTRY(31);
SYSG((u32)isr128, this_cpu.idt[0x80]);// SYStem Call goes here
ISR_ENTRY(255);
IRQ_ENTRY(0); IRQ_ENTRY(1); IRQ_ENTRY(2); IRQ_ENTRY(3); IRQ_ENTRY(4); IRQ_ENTRY(5);
IRQ_ENTRY(6); IRQ_ENTRY(7); IRQ_ENTRY(8); IRQ_ENTRY(9); IRQ_ENTRY(10); IRQ_ENTRY(11);
IRQ_ENTRY(12); IRQ_ENTRY(13); IRQ_ENTRY(14); IRQ_ENTRY(15);
write_tss(&this_cpu.gdt[GDT_TSS_ENTRY], __KERNEL_DS, 0x0);
this_cpu.idt_ptr.limit = IDT_ENTRY_NUM * sizeof(struct idt_desc_struct);
this_cpu.idt_ptr.base = (u32)&(this_cpu.idt);
gdt_flush((u32)&(this_cpu.gdt_ptr));
init_8259A();
irq_enable(2);
memset((u8 *)&interrupt_handlers , 0, sizeof(interrupt_handlers));
idt_flush((u32)&(this_cpu.idt_ptr));
tss_flush();
}
void gdt_init(void)
{
/* that's kind of ugly (setting the null segment) */
memset(&gdt[SEG_NULL_IDX], 0x0, sizeof(struct gdt_entry));
/* 0x08 */
gdt_set_segment(SEG_KCODE_IDX, 0x0, 0xffffffff,
GDTE_DPL_KERNEL | GDTE_X | GDTE_W | GDTE_NOT_TSS,
GDTE_PAGE_GRAN | GDTE_32_BIT);
/* 0x10 */
gdt_set_segment(SEG_KDATA_IDX, 0x0, 0xffffffff,
GDTE_DPL_KERNEL | GDTE_R | GDTE_NOT_TSS,
GDTE_PAGE_GRAN | GDTE_32_BIT);
/* 0x18 */
gdt_set_segment(SEG_UCODE_IDX, 0x0, 0xffffffff,
GDTE_DPL_USER | GDTE_X | GDTE_W | GDTE_NOT_TSS,
GDTE_PAGE_GRAN | GDTE_32_BIT);
/* 0x20 */
gdt_set_segment(SEG_UDATA_IDX, 0x0, 0xffffffff,
GDTE_DPL_USER | GDTE_R | GDTE_NOT_TSS,
GDTE_PAGE_GRAN | GDTE_32_BIT);
/* task switching structure */
tss_init(SEG_KDATA, (uint32_t)&kernel_stack_top);
gdt_install();
kprintf("[gdt] global descriptors were set up\n");
tss_flush(SEG_TSS);
}
void init_gdt()
{
//Sets up the gdt pointer
gdtp.limit = (sizeof(struct gdt_entry)*GDT_LEN)-1;
gdtp.base = (unsigned int)&gdt_table;
/*the first NULL entry*/
gdt_set_gate(0, 0,0,0,0);
// 0x9A, 0x92, 0xFA, 0xF2
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
// Ok, add the tss
set_tss(5, 0x10, 0x0);
/*actually flushes gdt with lgdt code*/
gdt_flush((unsigned int)&gdtp);
// now flush the TSS
tss_flush();
}
void init_gdt()
{
gdt_ptr.size = (sizeof(gdt_entry_t) * 6) - 1;
gdt_ptr.base = (u32int)&gdt_entries;
gdt_set(0, 0, 0, 0, 0); // Null segment
gdt_set(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); // Code segment
gdt_set(2, 0, 0xFFFFFFFF, 0x92, 0xCF); // Data segment
gdt_set(3, 0, 0xFFFFFFFF, 0xFA, 0xCF); // User mode code segment
gdt_set(4, 0, 0xFFFFFFFF, 0xF2, 0xCF); // User mode data segment
write_tss(5, 0x10, 0x0);
gdt_flush((u32int)&gdt_ptr);
tss_flush();
}
/* Should be called by main. This will setup the special GDT
* pointer, set up the first 5 entries in our GDT, and then
* finally call gdt_flush() in our assembler file in order
* to tell the processor where the new GDT is and update the
* new segment registers */
static void gdt_init() {
/* Setup the GDT pointer and limit */
gdt_ptr.limit = (sizeof(gdt_entry_t) * 6) - 1;
gdt_ptr.base = (uint32_t)&gdt_entries;
gdt_set_gate(0, 0, 0, 0, 0); /* Null segment */
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); /* Code segment */
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF); /* Data segment */
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF); /* User mode code segment */
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF); /* User mode data segment */
tss_write(5, 0x10, 0x0);
/* Flush out the old GDT and install the new changes */
gdt_flush((uint32_t)&gdt_ptr);
tss_flush();
}
void gdt_install(void)
{
gdtpointer.limit = (sizeof(struct gdt_entry) * NUM_OF_GDT) - 1;
gdtpointer.base = (u32)&gdt;
gdt_set_gate(0,0,0,0,0);
gdt_set_gate(1,0,0xffffffff,0x9a, 0xcf);
gdt_set_gate(2,0,0xffffffff,0x92, 0xcf);
gdt_set_gate(3,0,0xffffffff,0xfa, 0xcf); /*usermode*/
gdt_set_gate(4,0,0xffffffff,0xf2, 0xcf); /*usermode*/
write_tss(5,0x10,0x0);
gdt_flush();
tss_flush();
}
void gdt_init()
{
memset(&gdt_entries, 0, sizeof(gdt_entries));
gdt_set_gate(0, 0, 0, 0, 0); // 0x0 Null segment
gdt_set_gate(1, 0, 0xFFFF, 0x98, 0x20); // 0x8 Kernel Code segment
gdt_set_gate(2, 0, 0xFFFF, 0x90, 0x00); // 0x10 Kernel Data segment
gdt_set_gate(3, 0, 0xFFFF, 0xF8, 0x20); // 0x18 User mode code segment
gdt_set_gate(4, 0, 0xFFFF, 0xF0, 0x00); // 0x20 User mode data segment
gdt_set_tss(); // 0x28 TSS64
gdt_ptr.limit = sizeof(gdt_entries) - 1;
gdt_ptr.base = (u64)&gdt_entries;
gdt_flush(&gdt_ptr);
tss_flush();
}
/*
* gdt_install
* Install the kernel's GDTs
*/
void
gdt_install(void) {
/* GDT pointer and limits */
gp.limit = (sizeof(struct gdt_entry) * 6) - 1;
gp.base = (unsigned int)&gdt;
/* NULL */
gdt_set_gate(0, 0, 0, 0, 0);
/* Code segment */
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
/* Data segment */
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
/* User code */
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
/* User data */
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
write_tss(5, 0x10, 0x0);
/* Go go go */
gdt_flush();
tss_flush();
}
static void init_gdt() {
gdt_ptr.limit = (sizeof(gdt_entry_t) * GDT_ENTRIES) - 1;
gdt_ptr.base = (u32int)&gdt_entries;
gdt_set_gate(0, 0, 0, 0, 0); // Null segment
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); // Code segment
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF); // Data segment
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF); // User mode code segment
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF); // User mode data segment
gdt_set_gate(5, 0, 0, 0xF2, 0xCF); // User mode tlb segment
// u32 base = KERNEL_VIRTUAL_BASE - cpu::cPageSize;
// u32 limit = cpu::cPageSize;
// gdt_set_gate(5, base, limit, 0xF2, 0xCF); // User mode tlb segment
write_tss(6, 0x10, 0x0);
gdt_set_gate(7, 0, 0, 0x92, 0xCF); // Percpu segment
gdt_flush((u32int)&gdt_ptr);
tss_flush();
}
void init_gdt(uint32_t kstack_ptr) {
// We have six entries in the GDT - two for kernel mode,
// two for user mode, the NULL descriptor,
// and one for the TSS (task state segment)
// The limit is the last valid byte from the start of the GDT
// - i.e. the size of the GDT - 1.
gdt_ptr.limit = sizeof(gdt_entry_t) * 6 - 1;
gdt_ptr.base = (uint32_t) &gdt_entries;
gdt_set_gate(0, 0, 0, 0, 0); // null segment
gdt_set_gate(1, 0, 0xFFFFF, 0x9A, 0xCF); // kernel code
gdt_set_gate(2, 0, 0xFFFFF, 0x92, 0xCF); // kernel data
gdt_set_gate(3, 0, 0xFFFFF, 0xFA, 0xCF); // user code
gdt_set_gate(4, 0, 0xFFFFF, 0xF2, 0xCF); // user data
// we pass gdt_entry index, kernel stack data segment offset
// and kernel stack pointer
write_tss(5, 0x10, kstack_ptr);
gdt_flush((uint32_t) &gdt_ptr);
tss_flush();
}
/*
* gdt_install
* Install the kernel's GDTs
*/
void
gdt_install() {
blog("Setting up Global Descriptor Tables...");
/* GDT pointer and limits */
gp.limit = (sizeof(struct gdt_entry) * 6) - 1;
gp.base = (unsigned int)&gdt;
/* NULL */
gdt_set_gate(0, 0, 0, 0, 0);
/* Code segment */
gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
/* Data segment */
gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
/* User code */
gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
/* User data */
gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
write_tss(5, 0x10, 0x0);
/* Go go go */
gdt_flush();
tss_flush();
bfinish(0);
}
void create_gdt()
{
gdt_ptr.limit = sizeof(t_gdt_entry) * MAX_DESCRIPTORS - 1;
gdt_ptr.base = (u32)&gdt;
kmemset(gdt, 0, sizeof(gdt));
//Null Segment
gdt_set_descriptor(0, 0, 0, 0, 0);
//Code Segment
gdt_set_descriptor(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);
//Data Segment
gdt_set_descriptor(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
//User mode Code Segment
gdt_set_descriptor(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
//User mode Data Segment
gdt_set_descriptor(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
//TSS
load_default_tss();
gdt_flush((u32)&gdt_ptr);
tss_flush();
}