hos/src/hulk/idt.d
2022-12-14 19:40:22 -05:00

129 lines
3.1 KiB
D

/**
* IDT (Interrupt Descriptor Table) functionality.
*/
module hulk.idt;
import hulk.gdt;
import ldc.llvmasm;
import hulk.fb;
import hulk.console;
import hulk.klog;
import hulk.apic;
import hulk.rtc;
struct idt
{
/* IRQ 0 is interrupt 32 (0x20). */
public static enum ulong INT_RTC = 0x28u; /* IRQ 8 */
public static enum ulong INT_LAPIC_TIMER = 0x70u;
public static enum ulong INT_LAPIC_LINT0 = 0x71u;
public static enum ulong INT_LAPIC_LINT1 = 0x72u;
struct idtr_t
{
ushort limit;
align(2) ulong offset;
}
static assert(idtr_t.sizeof == 10u);
alias descriptor_t = ulong[2];
static __gshared align(0x10) descriptor_t[256] idt;
static assert(idt.sizeof == (256u * 16u));
static __gshared idtr_t idtr;
public static void initialize()
{
set_isrs();
idtr.limit = idt.sizeof - 1u;
idtr.offset = cast(ulong)&idt;
lidt(&idtr);
}
private static void lidt(idtr_t * idtr)
{
__asm("lidt $0", "*m", idtr);
}
private static bool isr_has_error_code(size_t isr)
{
return (isr == 8) ||
((10 <= isr) && (isr <= 14)) ||
(isr == 17) ||
(isr == 21) ||
(isr == 29) ||
(isr == 30);
}
private static bool isr_is_trap(size_t isr)
{
return (isr < 32u) && (isr != 2u);
}
private static void set_isrs()
{
ulong isr_address;
static foreach(isr; 0 .. 256)
{
mixin("isr_address = __asm!ulong(`
movabs $$1f, %rax
jmp 2f
1:
pushq %rdi
pushq %rsi
pushq %rax
mov $$", isr, ", %rdi
" ~ (isr_has_error_code(isr) ? "mov 0x18(%rsp), %rsi" : "") ~ "
movabs $$isr, %rax
callq *%rax
popq %rax
popq %rsi
popq %rdi
" ~ (isr_has_error_code(isr) ? "add $$8, %rsp" : "") ~ "
iretq
2:`, `={rax}`);");
mixin("set_descriptor(", isr, ", 0u, " ~
(isr_is_trap(isr) ? "true" : "false") ~ ", isr_address);");
}
}
private static void set_descriptor(size_t index, ulong dpl, bool trap, ulong offset)
{
idt[index][0] =
0x0000_8E_00_0000_0000u |
((offset & 0xFFFF_0000u) << 32u) |
(dpl << 45u) |
((trap ? 1uL : 0uL) << 40u) |
(gdt.SELECTOR_KERNEL_CODE << 16u) |
(offset & 0xFFFFu);
idt[index][1] = offset >> 32u;
}
}
public extern(C) void isr(ulong vector, ulong arg)
{
switch (vector)
{
case idt.INT_RTC:
rtc.isr();
break;
case idt.INT_LAPIC_TIMER:
case idt.INT_LAPIC_LINT0:
case idt.INT_LAPIC_LINT1:
apic.isr(vector);
break;
default:
console.clear();
fb.clear(0xFF8000u);
klog.writefln("ISR %u, 0x%x", vector, arg);
__asm("cli", "");
for (;;)
{
__asm("hlt", "");
}
}
}