mirror of
https://github.com/tailix/kernel.git
synced 2024-10-30 12:03:52 -04:00
88 lines
2.3 KiB
C
88 lines
2.3 KiB
C
#include "tss.h"
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#include "config.h"
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#include <kernelmq/stdlib.h>
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struct gdt_entry_bits {
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unsigned int limit_low : 16;
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unsigned int base_low : 24;
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unsigned int accessed : 1;
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unsigned int read_write : 1;
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unsigned int conforming_expand_down : 1;
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unsigned int code : 1;
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unsigned int always_1 : 1;
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unsigned int DPL : 2;
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unsigned int present : 1;
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unsigned int limit_high : 4;
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unsigned int available : 1;
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unsigned int always_0 : 1;
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unsigned int big : 1;
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unsigned int gran : 1;
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unsigned int base_high : 8;
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}
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__attribute__((packed));
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struct tss_entry {
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unsigned int prev_tss;
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unsigned int esp0;
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unsigned int ss0;
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unsigned int esp1;
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unsigned int ss1;
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unsigned int esp2;
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unsigned int ss2;
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unsigned int cr3;
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unsigned int eip;
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unsigned int eflags;
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unsigned int eax;
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unsigned int ecx;
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unsigned int edx;
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unsigned int ebx;
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unsigned int esp;
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unsigned int ebp;
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unsigned int esi;
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unsigned int edi;
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unsigned int es;
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unsigned int cs;
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unsigned int ss;
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unsigned int ds;
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unsigned int fs;
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unsigned int gs;
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unsigned int ldt;
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unsigned short trap;
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unsigned short iomap_base;
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}
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__attribute__((packed));
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static struct tss_entry tss;
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void tss_write_to_gdt(void *gdt_entry_ptr)
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{
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struct gdt_entry_bits *const g = gdt_entry_ptr;
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unsigned long base = (unsigned long)&tss;
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unsigned long limit = sizeof(tss);
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g->limit_low = limit & 0xFFFF;
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g->base_low = base & 0xFFFFFF;
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g->base_high = (base & 0xFF000000) >> 24;
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g->limit_high = (limit & 0xF0000) >> 16;
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g->accessed = 1;
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g->read_write = 0;
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g->conforming_expand_down = 0;
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g->code = 1;
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g->always_1 = 0;
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g->DPL = 3;
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g->present = 1;
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g->available = 0;
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g->always_0 = 0;
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g->big = 0;
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g->gran = 0;
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kmemset(&tss, 0, sizeof(tss));
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tss.ss0 = GDT_KERNEL_DS_SELECTOR;
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tss.esp0 = 0; // TODO: get from kinfo
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}
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