StuBS
LAPIC Namespace Reference

Abstracts the local APIC (which is integrated into every CPU core) More...

Namespaces

namespace  IPI
 Inter-Processor Interrupts.
 
namespace  Timer
 Local Timer (for each LAPIC / CPU)
 

Classes

union  DestinationFormatRegister
 Destination Format Register. More...
 
union  IdentificationRegister
 Local APIC ID (for Pentium 4 and newer) More...
 
union  LogicalDestinationRegister
 Logical Destination Register. More...
 
union  SpuriousInterruptVectorRegister
 Spurious Interrupt Vector Register. More...
 
union  TaskPriorityRegister
 Task Priority Register. More...
 
union  VersionRegister
 Local APIC Version. More...
 

Enumerations

enum  APICSoftware
 APIC Software Status for Spurious Interrupt Vector.
 
enum  FocusProcessorChecking
 Focus Processor Checking for Spurious Interrupt Vector.
 
enum  SuppressEOIBroadcast
 Suppress End-Of-Interrupt-Broadcast for Spurious Interrupt Vector.
 
enum  Index : uint16_t {
  IDENTIFICATION = 0x020 , VERSION = 0x030 , TASK_PRIORITY = 0x080 , EOI = 0x0b0 ,
  LOGICAL_DESTINATION = 0x0d0 , DESTINATION_FORMAT = 0x0e0 , SPURIOUS_INTERRUPT_VECTOR = 0x0f0 , INTERRUPT_COMMAND_REGISTER_LOW = 0x300 ,
  INTERRUPT_COMMAND_REGISTER_HIGH = 0x310 , TIMER_CONTROL = 0x320 , TIMER_INITIAL_COUNTER = 0x380 , TIMER_CURRENT_COUNTER = 0x390 ,
  TIMER_DIVIDE_CONFIGURATION = 0x3e0
}
 Register Offset Index. More...
 

Functions

Register read (Index idx)
 Get value from APIC register. More...
 
void write (Index idx, Register value)
 Write value to APIC register. More...
 
uint8_t getID ()
 Get the ID of the current core's LAPIC. More...
 
uint8_t getLogicalID ()
 Get the Logical ID of the current core's LAPIC. More...
 
uint8_t getVersion ()
 Get version number of local APIC. More...
 
void init (uint8_t logical_id)
 Initialized the local APIC of the calling CPU core and sets the logical LAPIC ID in the LDR register. More...
 
void endOfInterrupt ()
 Signalize EOI (End of interrupt) More...
 
void setLogicalID (uint8_t id)
 Set the Logical ID of the current core's LAPIC. More...
 

Variables

volatile uintptr_t base_address = 0xfee00000
 Base Address used with offset to access memory mapped registers.
 

Detailed Description

Abstracts the local APIC (which is integrated into every CPU core)

In modern (x86) PCs, every CPU core has its own Local APIC (LAPIC). The LAPIC is the link between the local CPU core and the I/O APIC (that takes care about external interrupt sources. Interrupt messages received by the LAPIC will be passed to the corresponding CPU core and trigger the interrupt handler on this core.

See also
ISDMv3 10.4 Local APIC

Enumeration Type Documentation

◆ Index

enum LAPIC::Index : uint16_t

Register Offset Index.

See also
ISDMv3 10.4.1 The Local APIC Block Diagram
Enumerator
IDENTIFICATION 

Local APIC ID Register, RO (sometimes R/W). Do not change!

VERSION 

Local APIC Version Register, RO.

TASK_PRIORITY 

Task Priority Register, R/W.

EOI 

EOI Register, WO.

LOGICAL_DESTINATION 

Logical Destination Register, R/W.

DESTINATION_FORMAT 

Destination Format Register, bits 0-27 RO, bits 28-31 R/W.

SPURIOUS_INTERRUPT_VECTOR 

Spurious Interrupt Vector Register, bits 0-8 R/W, bits 9-1 R/W.

INTERRUPT_COMMAND_REGISTER_LOW 

Interrupt Command Register 1, R/W.

INTERRUPT_COMMAND_REGISTER_HIGH 

Interrupt Command Register 2, R/W.

TIMER_CONTROL 

LAPIC timer control register, R/W.

TIMER_INITIAL_COUNTER 

LAPIC timer initial counter register, R/W.

TIMER_CURRENT_COUNTER 

LAPIC timer current counter register, RO.

TIMER_DIVIDE_CONFIGURATION 

LAPIC timer divide configuration register, RW.

Function Documentation

◆ endOfInterrupt()

void LAPIC::endOfInterrupt ( )

Signalize EOI (End of interrupt)

Signalizes the LAPIC that the handling of the current interrupt finished. This function must be called at the end of interrupt handling before ireting.

◆ getID()

uint8_t LAPIC::getID ( )

Get the ID of the current core's LAPIC.

Returns
LAPIC ID

◆ getLogicalID()

uint8_t LAPIC::getLogicalID ( )

Get the Logical ID of the current core's LAPIC.

Returns
Logical ID

◆ getVersion()

uint8_t LAPIC::getVersion ( )

Get version number of local APIC.

Returns
version number

◆ init()

void LAPIC::init ( uint8_t  logical_id)

Initialized the local APIC of the calling CPU core and sets the logical LAPIC ID in the LDR register.

Parameters
logical_idAPIC ID to be set

◆ read()

Register LAPIC::read ( Index  idx)

Get value from APIC register.

Parameters
idxRegister Offset Index
Returns
current value of register

◆ setLogicalID()

void LAPIC::setLogicalID ( uint8_t  id)

Set the Logical ID of the current core's LAPIC.

Parameters
idnew Logical ID

◆ write()

void LAPIC::write ( Index  idx,
Register  value 
)

Write value to APIC register.

Parameters
idxRegister Offset Index
valuevalue to be written into register