Add idt module and set up IDT

src/hulk/idt.d

@@ -0,0 +1,105 @@
+/**
+ * IDT (Interrupt Descriptor Table) functionality.
+ */
+module hulk.idt;
+
+import hulk.gdt;
+import ldc.llvmasm;
+import hulk.fb;
+import hulk.console;
+import hulk.klog;
+
+struct idt
+{
+    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)
+{
+    console.initialize();
+    fb.clear(0xFF8000u);
+    klog.writefln("ISR %u, 0x%x", vector, arg);
+    __asm("cli", "");
+    for (;;)
+    {
+        __asm("hlt", "");
+    }
+}