60 lines
1.1 KiB
C
60 lines
1.1 KiB
C
#pragma once
|
|
#include "gdt/gdtc.h"
|
|
#include "../../lib/include/string.h"
|
|
|
|
struct TaskStateSegment {
|
|
uint32_t prev_tss;
|
|
uint32_t esp0;
|
|
uint32_t ss0;
|
|
// everythinge else is unused
|
|
uint32_t esp1;
|
|
uint32_t ss1;
|
|
uint32_t esp2;
|
|
uint32_t ss2;
|
|
uint32_t cr3;
|
|
uint32_t eip;
|
|
uint32_t eflags;
|
|
uint32_t eax;
|
|
uint32_t ecx;
|
|
uint32_t edx;
|
|
uint32_t ebx;
|
|
uint32_t esp;
|
|
uint32_t ebp;
|
|
uint32_t esi;
|
|
uint32_t edi;
|
|
uint32_t es;
|
|
uint32_t cs;
|
|
uint32_t ss;
|
|
uint32_t ds;
|
|
uint32_t fs;
|
|
uint32_t gs;
|
|
uint32_t ldt;
|
|
uint16_t trap;
|
|
uint16_t iomap_base;
|
|
}__attribute__((packed));
|
|
|
|
|
|
TaskStateSegment tss0 = {};
|
|
|
|
inline void flush_tss(){
|
|
asm volatile("mov (5 * 8) |0 , %eax; ltr %ax");
|
|
}
|
|
|
|
|
|
void setup_tss(){
|
|
|
|
|
|
// ensure the tss is zero'd
|
|
//memset((void*)&tss0, 0, sizeof(tss0));
|
|
tss0.ss0 = (uint32_t) &(GlobalDescriptorTable[KERNEL_DATA_SEGMENT]);
|
|
uint32_t esp_addr =0 ;
|
|
asm volatile ("movl %%esp, %0" : "=a"(esp_addr));
|
|
tss0.esp0 = esp_addr;
|
|
|
|
|
|
// Task Segment Descriptor
|
|
add_descriptor(TASK_STATE_SEGMENT, (unsigned long)&tss0, sizeof(tss0), 0x89, 0x0);
|
|
flush_tss();
|
|
}
|
|
|