#include "idt.h"

#include "core_interrupt.h"

namespace IDT {

// Interrupt Descriptor Table, 8 Byte aligned
constinit struct InterruptDescriptor idt[256] = {};

// Struct used for loading (the address of) the Interrupt Descriptor Table into
// the IDT-Register
struct Register {
  uint16_t limit;  // Address of the last valid byte (relative to base)
  struct InterruptDescriptor* base;
  explicit Register(uint8_t max = 255) {
    limit = (max + static_cast<uint16_t>(1)) * sizeof(InterruptDescriptor) - 1;
    base = idt;
  }
} __attribute__((packed));

static_assert(sizeof(InterruptDescriptor) == 16,
              "IDT::InterruptDescriptor has wrong size");
static_assert(sizeof(Register) == 10, "IDT::Register has wrong size");
static_assert(alignof(decltype(idt)) % 8 == 0, "IDT must be 8 byte aligned!");

void load() {
  // Create structure required for writing to idtr and load via lidt
  Register idtr(Core::Interrupt::VECTORS - 1);
  asm volatile("lidt %0\n\t" ::"m"(idtr));
}

void set(Core::Interrupt::Vector vector, InterruptDescriptor descriptor) {
  idt[(uint8_t)vector] = descriptor;
}
}  // namespace IDT