idtirq.h File Reference

#include <global.h>
#include <types/nums.h>

Go to the source code of this file.

Data Structures
struct	IdtEntry
struct	GdtEntry
struct	GdtPtr
struct	IdtPtr

Macros
#define	KERNEL_CODE_SEGMENT   0x08
#define	IDT_ENTRIES   256
#define	PIT_FREQ   119
#define	SendEOI   Outb(0x20, 0x20)

Functions
void	SetupIdt (void)
void	IdtInit (void)
void	IdtSetGate (u8 num, u32 base, u16 sel, u8 flags)
	Set an IDT gate (entry) at given index.
void	MaskAllIrqs (void)
	Mask all IRQs.
void	UnmaskIrq (u8 irq)
	Unmask an IRQ.
void	DebugPrintIdtEntry (int i)
void	AllIdt ()
	Initialize and load the Interrupt Descriptor Table (IDT)
void	_picr (void)
void	GdtInstall ()
	Initialize and load the Global Descriptor Table (GDT)
void	GdtFlush (u32)
void	GdtSetGate (int num, u32 base, u32 limit, u8 access, u8 gran)
	Set a GDT entry (descriptor)
void	MsSleep (unsigned int milliseconds)
void	PitInit (u32 freq)
void	Irq0HandlerC (void)
void	Irq0Handler (void)
void	GoodHandler (void)
void	Irq1Handler (void)
void	VirtnetIrqHandler ()
void	VirtnetHandler (void)

Variables
struct IdtEntry	PKG
struct IdtPtr	idt_ptrn
struct IdtEntry	idt [IDT_ENTRIES]

Macro Definition Documentation

IDT_ENTRIES

#define IDT_ENTRIES   256

Definition at line 92 of file idtirq.h.

KERNEL_CODE_SEGMENT

#define KERNEL_CODE_SEGMENT   0x08

Definition at line 24 of file idtirq.h.

PIT_FREQ

#define PIT_FREQ   119

Definition at line 107 of file idtirq.h.

SendEOI

#define SendEOI   Outb(0x20, 0x20)

Definition at line 108 of file idtirq.h.

Function Documentation

_picr()

void _picr ( void )

extern

AllIdt()

void AllIdt

(

)

Initialize and load the Interrupt Descriptor Table (IDT)

• Installs GDT
• Remaps PIC interrupts
• Masks all IRQs, then unmasks IRQ 0 and 1
• Sets IDT gates for IRQ0 and IRQ1 handlers
• Loads the IDT and enables interrupts
• Starts the PIT timer at a base frequency

< Install the Global Descriptor Table (GDT)

< Remap the PIC (Programmable Interrupt Controller)

< Mask all IRQs for safety

< Unmask IRQ1 (keyboard)

< Unmask IRQ0 (timer)

< Clear the IDT entries

< Set IDT limit

< Set IDT base address

< Set IRQ0 handler

< Set IRQ1 handler

< Disable CPU interrupts during setup

< Reload the GDT

< Load the new IDT

< Re-enable CPU interrupts

< Initialize PIT with base frequency (e.g., 1193182 Hz)

Definition at line 73 of file idt.c.

DebugPrintIdtEntry()

void DebugPrintIdtEntry

(

int

i

)

GdtFlush()

void GdtFlush ( u32 )

extern

GdtInstall()

void GdtInstall

(

)

Initialize and load the Global Descriptor Table (GDT)

• Sets up three GDT entries:
  • Null segment
  • Code segment (executable, readable)
  • Data segment (read/write)
• Loads the GDT register with the new table

Definition at line 56 of file gdt.c.

GdtSetGate()

void GdtSetGate	(	int	num,
		u32	base,
		u32	limit,
		u8	access,
		u8	gran )

Set a GDT entry (descriptor)

Parameters

num	Index of the GDT entry to set
base	Base address for the segment
limit	Limit of the segment
access	Access flags (e.g., executable, readable)
gran	Granularity and size flags

Definition at line 35 of file gdt.c.

GoodHandler()

void GoodHandler ( void )

extern

IdtInit()

void IdtInit

(

void

)

IdtSetGate()

void IdtSetGate	(	u8	num,
		u32	base,
		u16	sel,
		u8	flags )

Set an IDT gate (entry) at given index.

Parameters

num	Index of the IDT entry to set
base	Address of the interrupt handler function
sel	Code segment selector in GDT
flags	Flags controlling gate type and privileges

Definition at line 40 of file idt.c.

Irq0Handler()

void Irq0Handler ( void )

extern

Irq0HandlerC()

void Irq0HandlerC

(

void

)

Definition at line 24 of file irq0.c.

Irq1Handler()

void Irq1Handler ( void )

extern

MaskAllIrqs()

void MaskAllIrqs

(

void

)

Mask all IRQs.

Definition at line 26 of file masker.c.

MsSleep()

void MsSleep

(

unsigned int

milliseconds

)

Definition at line 29 of file irq0.c.

PitInit()

void PitInit

(

u32

freq

)

Definition at line 32 of file pit.c.

SetupIdt()

void SetupIdt

(

void

)

UnmaskIrq()

void UnmaskIrq

(

u8

irq

)

Unmask an IRQ.

Parameters

irq	- IRQ NUmber to Unmask

Definition at line 34 of file masker.c.

VirtnetHandler()

void VirtnetHandler ( void )

extern

VirtnetIrqHandler()

void VirtnetIrqHandler

(

)

Definition at line 11 of file virtnetirq.c.

Variable Documentation

idt

struct IdtEntry idt[IDT_ENTRIES]

extern

Interrupt Descriptor Table entries

Definition at line 27 of file idt.c.

idt_ptrn

struct IdtPtr idt_ptrn

extern

PKG

struct GdtPtr PKG