Advance HH, GDT, IDT (details below)

- Implement higher-half in loader with paging (using 4Mb pages)
- Add GDT installation code
- Add IDT installation code (spend a loong time debugging the ISRs!)
- Add CDROM generation scripts
- Add scripts to launch bochs (debug) and qemu (debug)

1 files changed, 40 insertions, 0 deletions

diff --git a/kernel/include/idt.h b/kernel/include/idt.h
new file mode 100644
index 0000000..5730f5e
--- /dev/null
+++ b/kernel/include/idt.h
@@ -0,0 +1,40 @@
+#pragma once
+
+/*	The IDT is the system descriptor table that tells the CPU what to do when an interrupt fires.
+	There are three categories of interrupts :
+	- Exceptions ; eg page fault, divide by 0
+	- IRQ : interrupts caused by hardware
+	- System calls : when an applications asks the system to do something */
+
+#include <config.h>
+
+struct idt_entry {
+	uint16_t base_lo;		//Low part of address to jump to
+	uint16_t sel;			//Kernel segment selector
+	uint8_t always0;
+	uint8_t flags;			//Flags
+	uint16_t base_hi;		//High part of address to jump to
+} __attribute__((packed));
+typedef struct idt_entry idt_entry_t;
+
+struct idt_ptr {
+	uint16_t limit;
+	uint32_t base;
+} __attribute__((packed));
+typedef struct idt_ptr idt_ptr_t;
+
+struct registers {
+	uint32_t ds;                  // Data segment selector
+	uint32_t edi, esi, ebp, useless_esp, ebx, edx, ecx, eax; // Pushed by pusha.
+	uint32_t int_no, err_code;    // Interrupt number and error code (if applicable)
+	uint32_t eip, cs, eflags, esp, ss; // Pushed by the processor automatically.
+};
+typedef struct registers registers_t;
+
+typedef void (*isr_handler_t)(registers_t*);
+
+void idt_init();
+//void idt_handleIrq(int number, isr_handler_t func);	//Set IRQ handler
+
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/