Mark
dada247460
http://web.archive.org/web/20210423124630/https://github.com/jdah/tetris-os/blob/master/README.md
40 lines
876 B
C
40 lines
876 B
C
#include "idt.h"
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struct IDTEntry {
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u16 offset_low;
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u16 selector;
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u8 __ignored;
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u8 type;
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u16 offset_high;
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} PACKED;
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struct IDTPointer {
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u16 limit;
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uintptr_t base;
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} PACKED;
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static struct {
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struct IDTEntry entries[256];
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struct IDTPointer pointer;
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} idt;
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// in start.S
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extern void idt_load();
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void idt_set(u8 index, void (*base)(struct Registers*), u16 selector, u8 flags) {
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idt.entries[index] = (struct IDTEntry) {
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.offset_low = ((uintptr_t) base) & 0xFFFF,
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.offset_high = (((uintptr_t) base) >> 16) & 0xFFFF,
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.selector = selector,
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.type = flags | 0x60,
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.__ignored = 0
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};
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}
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void idt_init() {
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idt.pointer.limit = sizeof(idt.entries) - 1;
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idt.pointer.base = (uintptr_t) &idt.entries[0];
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memset(&idt.entries[0], 0, sizeof(idt.entries));
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idt_load((uintptr_t) &idt.pointer);
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}
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