const idt = @import("idt.zig");

// Interrupt Service Routines defined externally in assembly.
extern fn isr0() void;
extern fn isr1() void;
extern fn isr2() void;
extern fn isr3() void;
extern fn isr4() void;
extern fn isr5() void;
extern fn isr6() void;
extern fn isr7() void;
extern fn isr8() void;
extern fn isr9() void;
extern fn isr10() void;
extern fn isr11() void;
extern fn isr12() void;
extern fn isr13() void;
extern fn isr14() void;
extern fn isr15() void;
extern fn isr16() void;
extern fn isr17() void;
extern fn isr18() void;
extern fn isr19() void;
extern fn isr20() void;
extern fn isr21() void;
extern fn isr22() void;
extern fn isr23() void;
extern fn isr24() void;
extern fn isr25() void;
extern fn isr26() void;
extern fn isr27() void;
extern fn isr28() void;
extern fn isr29() void;
extern fn isr30() void;
extern fn isr31() void;
extern fn isr32() void;
extern fn isr33() void;
extern fn isr34() void;
extern fn isr35() void;
extern fn isr36() void;
extern fn isr37() void;
extern fn isr38() void;
extern fn isr39() void;
extern fn isr40() void;
extern fn isr41() void;
extern fn isr42() void;
extern fn isr43() void;
extern fn isr44() void;
extern fn isr45() void;
extern fn isr46() void;
extern fn isr47() void;
extern fn isr128() void;

// Context saved by Interrupt Service Routines.
pub const Context = packed struct {
    registers: Registers, // General purpose registers.

    interrupt_n: u32, // Number of the interrupt.
    error_code: u32, // Associated error code (or 0).

    // CPU status:
    eip: u32,
    cs: u32,
    eflags: u32,
    esp: u32,
    ss: u32,

    // pub inline fn setReturnValue(self: *volatile Context, value: var) void {
    //     self.registers.eax = if (@TypeOf(value) == bool) @boolToInt(value) else @intCast(u32, value);
    // }
};

// Structure holding general purpose registers as saved by PUSHA.
pub const Registers = packed struct {
    edi: u32,
    esi: u32,
    ebp: u32,
    esp: u32,
    ebx: u32,
    edx: u32,
    ecx: u32,
    eax: u32,
};

// Pointer to the current saved context.
pub export var context: *volatile Context = undefined;
////
// Install the Interrupt Service Routines in the IDT.
//
pub fn install_exceptions() void {
    // Exceptions.
    idt.setGate(1, idt.INTERRUPT_GATE, isr1);
    idt.setGate(2, idt.INTERRUPT_GATE, isr2);
    idt.setGate(3, idt.INTERRUPT_GATE, isr3);
    idt.setGate(4, idt.INTERRUPT_GATE, isr4);
    idt.setGate(5, idt.INTERRUPT_GATE, isr5);
    idt.setGate(6, idt.INTERRUPT_GATE, isr6);
    idt.setGate(7, idt.INTERRUPT_GATE, isr7);
    idt.setGate(8, idt.INTERRUPT_GATE, isr8);
    idt.setGate(9, idt.INTERRUPT_GATE, isr9);
    idt.setGate(10, idt.INTERRUPT_GATE, isr10);
    idt.setGate(11, idt.INTERRUPT_GATE, isr11);
    idt.setGate(12, idt.INTERRUPT_GATE, isr12);
    idt.setGate(13, idt.INTERRUPT_GATE, isr13);
    idt.setGate(14, idt.INTERRUPT_GATE, isr14);
    idt.setGate(15, idt.INTERRUPT_GATE, isr15);
    idt.setGate(16, idt.INTERRUPT_GATE, isr16);
    idt.setGate(17, idt.INTERRUPT_GATE, isr17);
    idt.setGate(18, idt.INTERRUPT_GATE, isr18);
    idt.setGate(19, idt.INTERRUPT_GATE, isr19);
    idt.setGate(20, idt.INTERRUPT_GATE, isr20);
    idt.setGate(21, idt.INTERRUPT_GATE, isr21);
    idt.setGate(22, idt.INTERRUPT_GATE, isr22);
    idt.setGate(23, idt.INTERRUPT_GATE, isr23);
    idt.setGate(24, idt.INTERRUPT_GATE, isr24);
    idt.setGate(25, idt.INTERRUPT_GATE, isr25);
    idt.setGate(26, idt.INTERRUPT_GATE, isr26);
    idt.setGate(27, idt.INTERRUPT_GATE, isr27);
    idt.setGate(28, idt.INTERRUPT_GATE, isr28);
    idt.setGate(29, idt.INTERRUPT_GATE, isr29);
    idt.setGate(30, idt.INTERRUPT_GATE, isr30);
    idt.setGate(31, idt.INTERRUPT_GATE, isr31);
}

// IRQs.
pub fn install_irqs() void {
    idt.setGate(32, idt.INTERRUPT_GATE, isr32);
    idt.setGate(33, idt.INTERRUPT_GATE, isr33);
    idt.setGate(34, idt.INTERRUPT_GATE, isr34);
    idt.setGate(35, idt.INTERRUPT_GATE, isr35);
    idt.setGate(36, idt.INTERRUPT_GATE, isr36);
    idt.setGate(37, idt.INTERRUPT_GATE, isr37);
    idt.setGate(38, idt.INTERRUPT_GATE, isr38);
    idt.setGate(39, idt.INTERRUPT_GATE, isr39);
    idt.setGate(40, idt.INTERRUPT_GATE, isr40);
    idt.setGate(41, idt.INTERRUPT_GATE, isr41);
    idt.setGate(42, idt.INTERRUPT_GATE, isr42);
    idt.setGate(43, idt.INTERRUPT_GATE, isr43);
    idt.setGate(44, idt.INTERRUPT_GATE, isr44);
    idt.setGate(45, idt.INTERRUPT_GATE, isr45);
    idt.setGate(46, idt.INTERRUPT_GATE, isr46);
    idt.setGate(47, idt.INTERRUPT_GATE, isr47);
}

// Syscalls.
pub fn install_syscalls() void {
    idt.setGate(128, idt.SYSCALL_GATE, isr128);
}