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#include "interupt.h"
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typedef struct {
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uint16 offset_1; // offset 0 to 15 bits
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uint16 selector; // code segment sel
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uint8 reserved; // should be zero
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uint8 type_attr; // type & attr stuff
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uint16 offset_2; // offset 16 to 31
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} __attribute__((packed)) idt_entry;
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typedef struct {
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uint16 limit;
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uint base;
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} __attribute__((packed)) idtr;
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__attribute__((aligned(16)))
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static idt_entry IDT[IDT_MAX_DESCS];
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static idtr IDTR;
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void exception_handler() {
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__asm__ __volatile__("cli; hlt");
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}
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void interupt_handler() {
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__asm__("pusha");
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// handle stuff
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__asm__("popa; leave; iret");
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}
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void idt_set_desc(uint8 idx, void* isr, uint8 flags) {
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idt_entry* desc = &IDT[idx]; // get descriptor
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desc->offset_1 = (uint) isr & 0xffff;
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desc->selector = 0x08; // kernel code selector for the GDT (null is 0x0 - 0x4 => code is 0x05 to something...)
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desc->reserved = 0;
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desc->type_attr = flags;
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desc->offset_2 = (uint) isr >> 16;
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}
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extern void* isr_stub_table[];
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void idt_init() {
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IDTR.base = (uintptr) &IDT[0]; // base offset
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IDTR.limit = (uint16) sizeof(idt_entry) * IDT_MAX_DESCS - 1;
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for (uint8 idx = 0; idx < 32; idx++)
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idt_set_desc(idx, isr_stub_table[idx], 0x8e);
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__asm__ __volatile__("lidt %0" : : "m"(IDTR));
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__asm__ __volatile__("sti");
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}
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