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#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>
#define IRQ0 0 // PIT
#define IRQ1 1 // PCKBD
#define IRQ2 2 // not used
#define IRQ3 3 // COM2
#define IRQ4 4 // COM1
#define IRQ5 5 // LPT2
#define IRQ6 6 // Floppy
#define IRQ7 7 // LPT1
#define IRQ8 8 // CMOS RTC
#define IRQ9 9 // free -> PCI IRQ
#define IRQ10 10 // free -> PCI IRQ
#define IRQ11 11 // free -> PCI IRQ
#define IRQ12 12 // PS2 mouse
#define IRQ13 13 // FPU
#define IRQ14 14 // Primary ATA HD
#define IRQ15 15 // Secondary ATA HD
#define EX_DIVIDE_ERROR 0 // No error code
#define EX_DEBUG 1 // No error code
#define EX_NMI_INTERRUPT 2 // No error code
#define EX_BREAKPOINT 3 // No error code
#define EX_OVERFLOW 4 // No error code
#define EX_BOUND_RANGE_EXCEDEED 5 // No error code
#define EX_INVALID_OPCODE 6 // No error code
#define EX_DEVICE_NOT_AVAILABLE 7 // No error code
#define EX_DOUBLE_FAULT 8 // Yes (Zero)
#define EX_COPROCESSOR_SEGMENT_OVERRUN 9 // No error code
#define EX_INVALID_TSS 10 // Yes
#define EX_SEGMENT_NOT_PRESENT 11 // Yes
#define EX_STACK_SEGMENT_FAULT 12 // Yes
#define EX_GENERAL_PROTECTION 13 // Yes
#define EX_PAGE_FAULT 14 // Yes
#define EX_INTEL_RESERVED_1 15 // No
#define EX_FLOATING_POINT_ERROR 16 // No
#define EX_ALIGNEMENT_CHECK 17 // Yes (Zero)
#define EX_MACHINE_CHECK 18 // No
#define EX_INTEL_RESERVED_2 19 // No
#define EX_INTEL_RESERVED_3 20 // No
#define EX_INTEL_RESERVED_4 21 // No
#define EX_INTEL_RESERVED_5 22 // No
#define EX_INTEL_RESERVED_6 23 // No
#define EX_INTEL_RESERVED_7 24 // No
#define EX_INTEL_RESERVED_8 25 // No
#define EX_INTEL_RESERVED_9 26 // No
#define EX_INTEL_RESERVED_10 27 // No
#define EX_INTEL_RESERVED_11 28 // No
#define EX_INTEL_RESERVED_12 29 // No
#define EX_INTEL_RESERVED_13 30 // No
#define EX_INTEL_RESERVED_14 31 // No
#define EFLAGS_IF (0x1 << 9)
typedef 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.
} registers_t;
typedef void (*isr_handler_t)(registers_t*);
void idt_init();
void idt_set_ex_handler(int number, isr_handler_t func); //Set exception handler
void idt_set_irq_handler(int number, isr_handler_t func); //Set IRQ handler
// Warning about IRQ handlers :
// IRQ handlers may run on the kernel0 stack, which is reset each time the scheduler
// is entered. Therefore IRQ handler routines may not call yield(), which makes them
// unable to use mutexes, memory allocation and most usefull things. Basically the only
// thing they can do is wake up another thread, so it is a good idea to have a thread
// that waits for the IRQ and does something when it happens, and the IRQ handler only
// wakes up that thread when the IRQ happens. They may also communicate via atomical
// or lock free data structures.
void dbg_dump_registers(registers_t*);
/* vim: set ts=4 sw=4 tw=0 noet :*/
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