29 lines
811 B
C
29 lines
811 B
C
#include <kernel/gdt.h>
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void write_tss(struct tss_entry *tss, struct gdt_entry *gdt, int num, uint16_t ss0, uint32_t esp0) {
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uint32_t base = (uint32_t)tss;
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uint32_t limit = base + sizeof(struct tss_entry);
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gdt[num].base_low = base & 0xFFFF;
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gdt[num].base_middle = (base >> 16) & 0xFF;
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gdt[num].base_high = (base >> 24) & 0xFF;
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gdt[num].limit_low = limit & 0xFFFF;
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gdt[num].granularity = (limit >> 16) & 0x0F;
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gdt[num].granularity |= 0x40;
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gdt[num].access = 0x89;
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memset(&tss, 0, sizeof(struct tss_entry));
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tss->ss0 = ss0;
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tss->esp0 = esp0;
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tss->cs = 0x0b;
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tss->ss = tss->ds = tss->es = tss->fs = tss->gs = 0x13;
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}
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void tss_flush(uint16_t tss_selector) {
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asm volatile (
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"ltr %0"
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: // no output
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: "r" (tss_selector)
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);
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}
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