Collect the cpu specific stuff

src/kernel/cpu/cpu.c

@@ -0,0 +1,7 @@
+#include <cpu.h>
+#include <interrupts.h>
+
+void cpu_init()
+{
+  interrupt_init();
+}

src/kernel/cpu/interrupts.c

@@ -0,0 +1,44 @@
+#include <interrupts.h>
+#include <stdint.h>
+#include <memory.h>
+#include <debug.h>
+
+struct int_gate_descriptor idt[NUM_INTERRUPTS];
+struct idtr idtr;
+
+extern uintptr_t isr_table[];
+
+void idt_set_gate(uint32_t num, uintptr_t vector, uint16_t cs, uint8_t ist, uint8_t flags)
+{
+  idt[num].base_l = vector & 0xFFFF;
+  idt[num].base_m = (vector >> 16) & 0xFFFF;
+  idt[num].base_h = (vector >> 32) & 0xFFFFFFFF;
+  idt[num].cs = cs;
+  idt[num].ist = ist;
+  idt[num].flags = flags;
+}
+
+void interrupt_init()
+{
+  memset(idt, 0, sizeof(idt));
+
+  for(int i=0; i < NUM_INTERRUPTS; i++)
+  {
+    idt_set_gate(i, isr_table[i], 0x8, 0, IDT_PRESENT | IDT_DPL0 | IDT_INTERRUPT);
+  }
+
+  idtr.addr = idt;
+  idtr.len = sizeof(idt)-1;
+  load_idt(&idtr);
+}
+
+registers *int_handler(registers *r)
+{
+  (void)r;
+  debug("Unhandled interrupt occurred\n");
+  debug("Interrupt number: %d Error code: %d\n", r->int_no, r->err_code);
+  debug_print_registers(r);
+
+  PANIC("Unhandled interrupt occurred");
+  for(;;);
+}

src/kernel/cpu/interrupts.tt

@@ -0,0 +1,33 @@
+// vim: ft=c
+#include <ttest.h>
+#include <debug.h>
+#undef debug
+#define debug(...)
+#include "interrupts.c"
+
+uintptr_t isr_table[] ={};
+void load_idt(struct idtr *_)
+{
+  (void)_;
+}
+
+uint8_t *idt_raw = (uint8_t *)idt;
+
+TEST(idt_set_gate_correctly_sets_address_L)
+{
+  idt_set_gate(1, 0x1234567890ABCDEF, 0, 0, 0);
+
+  ASSERT_EQ_INT(*(uint16_t *)&idt_raw[16+0], 0xCDEF);
+}
+TEST(idt_set_gate_correctly_sets_address_M)
+{
+  idt_set_gate(1, 0x1234567890ABCDEF, 0, 0, 0);
+
+  ASSERT_EQ_INT(*(uint16_t *)&idt_raw[16+6], 0x90AB);
+}
+TEST(idt_set_gate_correctly_sets_address_H)
+{
+  idt_set_gate(1, 0x1234567890ABCDEF, 0, 0, 0);
+
+  ASSERT_EQ_INT(*(uint32_t *)&idt_raw[16+8], 0x12345678);
+}

src/kernel/cpu/isr.S.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+from __future__ import print_function
+
+num_isr = 256
+pushes_error = [8, 10, 11, 12, 13, 14, 17]
+
+print('''
+.intel_syntax noprefix
+.extern isr_common
+''')
+
+
+print('// Interrupt Service Routines')
+for i in range(num_isr):
+    print('''isr{0}:
+    cli
+    {1}
+    push {0}
+    jmp isr_common '''.format(i,
+        'push 0' if i not in pushes_error else 'nop'))
+
+print('')
+print('''
+// Vector table
+
+.section .data
+.global isr_table
+isr_table:''')
+
+for i in range(num_isr):
+    print('  .quad isr{}'.format(i))

src/kernel/cpu/isr_common.S

@@ -0,0 +1,50 @@
+.intel_syntax noprefix
+
+.global load_idt
+load_idt:
+  lidt [rdi]
+  ret
+
+.extern int_handler
+.global isr_common
+.global isr_return
+
+isr_common:
+  push r15
+  push r14
+  push r13
+  push r12
+  push r11
+  push r10
+  push r9
+  push r8
+  push rbp
+  push rdi
+  push rsi
+  push rdx
+  push rcx
+  push rbx
+  push rax
+  mov rdi, rsp
+  call int_handler
+
+  mov rdi, rax
+isr_return:
+  mov rsp, rdi
+  pop rax
+  pop rbx
+  pop rcx
+  pop rdx
+  pop rsi
+  pop rdi
+  pop rbp
+  pop r8
+  pop r9
+  pop r10
+  pop r11
+  pop r12
+  pop r13
+  pop r14
+  pop r15
+  add rsp, 0x10
+  iretq