idt.c File Reference

#include "idt.h"
#include "port.h"
#include "pic8259.h"
#include "debug.h"
#include "libc.h"
#include "Internal.h"
#include "x86int.h"
#include "asm_int.h"
#include "segment_selectors.h"
#include "gdt.h"
#include "Services.h"
#include "pip_interrupt_calls.h"

Data Structures
struct	idt_callback_conf_s

Macros
#define	DOUBLE_FAULT_LEVEL   8
#define	IRQ_CODE_SEGMENT   KERNEL_CODE_SEGMENT_SELECTOR
#define	IDT_INTERRUPT_ENTRY(callback_index)
	IDT interrupt entry initializer. idt_int_trap_entry_t Notice that the only difference with the IDT_TRAP_ENTRY macro is the type field. More...
#define	IDT_TRAP_ENTRY(callback_index)
	IDT trap entry initializer. idt_int_trap_entry_t Notice that the only difference with the IDT_INTERRUPT_ENTRY macro is the type field Trap gates do not clear the interrupt flag when accessed. More...
#define	PIC1_OFFSET   0x20
#define	PIC2_OFFSET   0x28

Functions
void	hardwareInterruptHandler (int_ctx_t *ctx)
void	softwareInterruptHandler (int_ctx_t *ctx)
void	propagateFault (page callerPartDesc, page callerPageDir, unsigned targetInterrupt, unsigned callerContextSaveIndex, unsigned nbL, interruptMask flagsOnYield, interruptMask flagsOnWake, user_ctx_t *callerInterruptedContext)
void	faultInterruptHandler (int_ctx_t *ctx)
void	initIDT (void)
void	remapIRQ (void)
void	timerPhase (uint32_t hz)
static void	cpuid (int code, uint32_t *a, uint32_t *d)
static int	cpuid_string (int code, uint32_t where[4])
void	initCPU ()
void	idt_init (void)

Variables
static struct idt_callback_conf_s	idt_callbacks [256]
	IRQ callbacks, privilege, and segment table This table associates IRQ numbers to handlers, as well as their privilege level and their segment (configured in the GDT). More...
static idt_entry_t	idt_entries [256]
uint32_t	pcid_enabled = 0
uint32_t	timer_ticks = 0

Macro Definition Documentation

DOUBLE_FAULT_LEVEL

#define DOUBLE_FAULT_LEVEL   8

IDT_INTERRUPT_ENTRY

#define IDT_INTERRUPT_ENTRY

(

callback_index

)

Value:

(idt_entry_t) {                              \
    .interrupt = {                                                                   \
        (((uint32_t) idt_callbacks[callback_index].callback) & 0xFFFF),          \
        (idt_callbacks[callback_index].segment),                                 \
        0,                                                                       \
        0,                                                                       \
        (INTERRUPT_GATE_TYPE),                                                   \
        (idt_callbacks[callback_index].dpl),                                     \
        1,                                                                       \
        ((((uint32_t) idt_callbacks[callback_index].callback) >> 16) & 0xFFFF)   \
    }                                                                                \
}

IDT interrupt entry initializer. idt_int_trap_entry_t Notice that the only difference with the IDT_TRAP_ENTRY macro is the type field.

IDT_TRAP_ENTRY

#define IDT_TRAP_ENTRY

(

callback_index

)

Value:

(idt_entry_t) {                                 \
    .trap = {                                                                      \
        (((uint32_t) idt_callbacks[callback_index].callback) & 0xFFFF),        \
        (idt_callbacks[callback_index].segment),                               \
        0,                                                                     \
        0,                                                                     \
        TRAP_GATE_TYPE,                                                        \
        idt_callbacks[callback_index].dpl,                                     \
        1,                                                                     \
        ((((uint32_t) idt_callbacks[callback_index].callback) >> 16) & 0xFFFF) \
    }                                                                              \
}

IDT trap entry initializer. idt_int_trap_entry_t Notice that the only difference with the IDT_INTERRUPT_ENTRY macro is the type field Trap gates do not clear the interrupt flag when accessed.

IRQ_CODE_SEGMENT

#define IRQ_CODE_SEGMENT   KERNEL_CODE_SEGMENT_SELECTOR

PIC1_OFFSET

#define PIC1_OFFSET   0x20

PIC2_OFFSET

#define PIC2_OFFSET   0x28

Function Documentation

cpuid()

static void cpuid ( int  code, uint32_t *  a, uint32_t *  d  )

inlinestatic

issue a single request to CPUID. Fits 'intel features', for instance note that even if only "eax" and "edx" are of interest, other registers will be modified by the operation, so we need to tell the compiler about it.

cpuid_string()

static int cpuid_string ( int  code, uint32_t  where[4]  )

inlinestatic

issue a complete request, storing general registers output as a string

faultInterruptHandler()

void faultInterruptHandler

(

int_ctx_t *

ctx

)

hardwareInterruptHandler()

void hardwareInterruptHandler

(

int_ctx_t *

ctx

)

idt_init()

void idt_init

(

void

)

initCPU()

void initCPU

(

)

initIDT()

void initIDT

(

void

)

Dynamic initialization of the IDT could be done statically through some obscure relative address black magic "https://wiki.osdev.org/IDT_problems#what_does_.22shift_operator_may_only_be_applied_to_scalar_values.22_mean.3F"

< Pointer to the IDT

propagateFault()

void propagateFault	(	page	callerPartDesc,
		page	callerPageDir,
		unsigned	targetInterrupt,
		unsigned	callerContextSaveIndex,
		unsigned	nbL,
		interruptMask	flagsOnYield,
		interruptMask	flagsOnWake,
		user_ctx_t *	callerInterruptedContext
	)

remapIRQ()

void remapIRQ

(

void

)

softwareInterruptHandler()

void softwareInterruptHandler

(

int_ctx_t *

ctx

)

timerPhase()

void timerPhase

(

uint32_t

hz

)

Variable Documentation

idt_callbacks

struct idt_callback_conf_s idt_callbacks[256]

static

IRQ callbacks, privilege, and segment table This table associates IRQ numbers to handlers, as well as their privilege level and their segment (configured in the GDT).

Some segment selector stuff :

• Faults are in kernel ring, because we won't explicitely trigger them from userland.
• But pipcalls may be triggered on purpose from userland (well, they should always be, in fact), so the other handlers' ring is USER (3).

idt_entries

idt_entry_t idt_entries[256]

static

Interrupt Descriptor Table Intel 64 and IA-32 Architectures Software Developer's Manual - Volume 3a - 6.10

pcid_enabled

uint32_t pcid_enabled = 0

timer_ticks

uint32_t timer_ticks = 0