eonix/include/kernel/interrupt.h

#pragma once

#include <types/types.h>

#ifdef __cplusplus
extern "C" {
#endif

#define KERNEL_INTERRUPT_GATE_TYPE (0x8e)
#define USER_INTERRUPT_GATE_TYPE (0xee)

#define PIC_EOI (0x20)

struct regs_32 {
    uint32_t edi;
    uint32_t esi;
    uint32_t ebp;
    uint32_t esp;
    uint32_t ebx;
    uint32_t edx;
    uint32_t ecx;
    uint32_t eax;
};

struct PACKED interrupt_stack {
    struct regs_32 s_regs;
    void* v_eip;
    uint32_t cs;
    uint32_t eflags;
    uint32_t esp;
    uint32_t ss;
};

// present: When set, the page fault was caused by a page-protection violation.
//          When not set, it was caused by a non-present page.
// write:   When set, the page fault was caused by a write access.
//          When not set, it was caused by a read access.
// user:    When set, the page fault was caused while CPL = 3.
//          This does not necessarily mean that the page fault was a privilege violation.
// from https://wiki.osdev.org/Exceptions#Page_Fault
struct page_fault_error_code {
    uint32_t present : 1;
    uint32_t write : 1;
    uint32_t user : 1;
    uint32_t reserved_write : 1;
    uint32_t instruction_fetch : 1;
    uint32_t protection_key : 1;
    uint32_t shadow_stack : 1;
    uint32_t software_guard_extensions : 1;
};

// external interrupt handler function
// stub in assembly MUST be called irqN
#define SET_UP_IRQ(N, SELECTOR)        \
    ptr_t addr_irq##N = (ptr_t)irq##N; \
    SET_IDT_ENTRY(0x20 + (N), (addr_irq##N), (SELECTOR), KERNEL_INTERRUPT_GATE_TYPE);

#define SET_IDT_ENTRY_FN(N, FUNC_NAME, SELECTOR, TYPE) \
    extern void FUNC_NAME();                           \
    ptr_t addr_##FUNC_NAME = (ptr_t)FUNC_NAME;         \
    SET_IDT_ENTRY((N), (addr_##FUNC_NAME), (SELECTOR), (TYPE));

#define SET_IDT_ENTRY(N, ADDR, SELECTOR, TYPE) \
    IDT[(N)].offset_low = (ADDR)&0x0000ffff;   \
    IDT[(N)].selector = (SELECTOR);            \
    IDT[(N)].zero = 0;                         \
    IDT[(N)].type_attr = (TYPE);               \
    IDT[(N)].offset_high = ((ADDR)&0xffff0000) >> 16

struct IDT_entry {
    uint16_t offset_low;
    uint16_t selector;
    uint8_t zero;
    uint8_t type_attr;
    uint16_t offset_high;
};

#ifndef _INTERRUPT_C_
extern struct IDT_entry IDT[256];
#endif

void init_idt(void);
void init_pic(void);

// idt_descriptor: uint16_t[3]
// [0] bit 0 :15 => limit
// [1] bit 16:47 => address
extern void asm_load_idt(uint16_t idt_descriptor[3], int sti);

void int13_handler(
    struct regs_32 s_regs,
    uint32_t error_code,
    ptr_t eip,
    uint16_t cs,
    uint32_t eflags);

void int0(void);
void int1(void);
void int2(void);
void int3(void);
void int4(void);
void int5(void);
void int6(void);
void int7(void);
void int8(void);
void int9(void);
void int10(void);
void int11(void);
void int12(void);
void int13(void);
void int14(void);

void irq0(void);
void irq1(void);
void irq2(void);
void irq3(void);
void irq4(void);
void irq5(void);
void irq6(void);
void irq7(void);
void irq8(void);
void irq9(void);
void irq10(void);
void irq11(void);
void irq12(void);
void irq13(void);
void irq14(void);
void irq15(void);

void syscall_stub(void);

#ifdef __cplusplus
}
#endif