Aufgabe 3: Pro-/Epilog

Enumerations | Functions | Constants
Core::Interrupt Namespace Reference

Exception and Interrupt control. More...

Enumerations

enum  Vector {
  DIVISON_BY_ZERO = 0 ,
  DEBUG = 1 ,
  NON_MASKABLE_INTERRUPT = 2 ,
  BREAKPOINT = 3 ,
  OVERFLOW = 4 ,
  BOUND_RANGE_EXCEEDED = 5 ,
  INVALID_OPCODE = 6 ,
  DEVICE_NOT_AVAILABLE = 7 ,
  DOUBLE_FAULT = 8 ,
  INVALID_TSS = 10 ,
  SEGMENT_NOT_PRESENT = 11 ,
  STACK_SEGMENT_FAULT = 12 ,
  GENERAL_PROTECTION_FAULT = 13 ,
  PAGE_FAULT = 14 ,
  FLOATING_POINT_EXCEPTION = 16 ,
  ALIGNMENT_CHECK = 17 ,
  MACHINE_CHECK = 18 ,
  SIMD_FP_EXCEPTION = 19 ,
  EXCEPTIONS = 32 ,
  TIMER = 32 ,
  KEYBOARD = 33 ,
  SERIAL = 34 ,
  GDB = 35 ,
  MOUSE = 44 ,
  PANIC = 99 ,
  ASSASSIN = 100 ,
  WAKEUP = 101 ,
  VECTORS = 256
}
 List of used interrupt vectors. More...
 

Functions

bool isEnabled ()
 Check if interrupts are enabled on this CPU. More...
 
void enable ()
 Allow interrupts. More...
 
bool disable ()
 Forbid interrupts. More...
 
void restore (bool val)
 Restore interrupt. More...
 

Constants

const uintptr_t FLAG_ENABLE = 1 << 9
 Bit in FLAGS register corresponding to the current interrupt state.
 

Detailed Description

Exception and Interrupt control.

See also
ISDMv3, Chapter 6 Interrupt and Exception Handling

Enumeration Type Documentation

enum Core::Interrupt::Vector

List of used interrupt vectors.

The exception vectors from 0 to 31 are reserved for traps, faults and aborts. Their behavior is different for each exception, some push an error code, some are not recoverable.

The vectors from 32 to 255 are user defined interrupts.

See also
ISDMv3, 6.15 Exception and Interrupt Reference
Optional:
Add interrupt vector for serial connection
Enumerator
DIVISON_BY_ZERO 

Divide-by-zero Error (at a DIV/IDIV instruction)

DEBUG 

Debug exception.

NON_MASKABLE_INTERRUPT 

Non Maskable Interrupt.

BREAKPOINT 

Breakpoint exception (used for debugging: GDB_Stub)

OVERFLOW 

Overflow exception (at INTO instruction)

BOUND_RANGE_EXCEEDED 

Bound Range Exceeded (at BOUND instruction)

INVALID_OPCODE 

Opcode at Instruction Pointer is invalid (you probably shouldn't be here)

DEVICE_NOT_AVAILABLE 

FPU/MMX/SSE instruction but corresponding extension not activate

DOUBLE_FAULT 

Exception occurred while trying to call exception/interrupt handler.

INVALID_TSS 

Invalid Task State Segment selector (see error code for index)

SEGMENT_NOT_PRESENT 

Segment not available (see error code for selector index)

STACK_SEGMENT_FAULT 

Stack segment not available or invalid (see error code for selector index)

GENERAL_PROTECTION_FAULT 

Operation not allowed (see error code for selector index)

PAGE_FAULT 

Operation on Page (r/w/x) not allowed for current privilege (error code + cr2)

FLOATING_POINT_EXCEPTION 

x87 FPU error (at WAIT/FWAIT), accidentally Core::CR0_NE set?

ALIGNMENT_CHECK 

Unaligned memory access in userspace (Exception activated by Core::CR0_AM)

MACHINE_CHECK 

Model specific exception.

SIMD_FP_EXCEPTION 

SSE/MMX error (if Core::CR4_OSXMMEXCPT activated)

EXCEPTIONS 

Number of exceptions.

TIMER 

Periodic CPU local LAPIC::Timer interrupt.

KEYBOARD 

Keyboard interrupt (key press / release)

SERIAL 

Receive interrupt of the Serial interface.

GDB 

Inter-processor interrupt to stop other CPUs for debugging in GDB.

MOUSE 

Mouse movement

PANIC 

Panic interrupt to stop CPU (default value for IOAPIC devices)

ASSASSIN 

Inter-processor interrupt to immediately stop threads running on other CPUs.

WAKEUP 

Inter-processor interrupt to WakeUp sleeping CPUs.

VECTORS 

Number of interrupt vectors.

Function Documentation

bool Core::Interrupt::isEnabled ( )
inline

Check if interrupts are enabled on this CPU.

This is done by pushing the FLAGS register onto stack, reading it into a register and checking the corresponding bit.

Returns
true if enabled, false if disabled
void Core::Interrupt::enable ( )
inline

Allow interrupts.

Enables interrupt handling by executing the instruction sti. Since this instruction is delayed by one cycle, an subsequent nop is executed (to ensure deterministic behavior, independent from the compiler generated code)

A pending interrupt (i.e., those arriving while interrupts were disabled) will be delivered after re-enabling interrupts.

See also
ISDMv2, Chapter 4. STI - Set Interrupt Flag
bool Core::Interrupt::disable ( void  )
inline

Forbid interrupts.

Prevents interrupt handling by executing the instruction cli. Will return the previous interrupt state.

Returns
true if interrupts were enabled at the time of executing this function, false if they were already disabled.
See also
ISDMv2, Chapter 3. CLI - Clear Interrupt Flag
void Core::Interrupt::restore ( bool  val)
inline

Restore interrupt.

Restore the interrupt state to the state prior to calling disable() by using its return value.

Note
This function will never disable interrupts, even if val is false! This function is designed to allow nested disabling and restoring of the interrupt state.
Parameters
valif set to true, interrupts will be enabled; nothing will happen on false.