WilsonOS/interrupts.cpp at master · wilsonandusa/WilsonOS · GitHub

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#include "interrupts.h"

void printf(char* str);


InterruptHandler::InterruptHandler(uint8_t interruptNumber, InterruptManager* interruptManager)
{
    this->interruptNumber = interruptNumber;
    this->interruptManager = interruptManager;
    interruptManager->handlers[interruptNumber] = this;
}

InterruptHandler::~InterruptHandler()
{
    if(interruptManager->handlers[interruptNumber] == this)
        interruptManager->handlers[interruptNumber] = 0;
}

uint32_t InterruptHandler::HandleInterrupt(uint32_t esp)
{
    return esp;
}

InterruptManager::GateDescriptor InterruptManager::interruptDescriptorTable[256];

InterruptManager* InterruptManager::ActiveInterruptManager = 0;

void InterruptManager::SetInterruptDescriptorTableEntry(
    uint8_t interruptNumber,
    uint16_t codeSegmentSelectorOffset,
    void (*handler)(),
    uint8_t DescriptorPrivilegeLebel,
    uint8_t DescriptorType)
{
    const uint8_t IDT_DESC_PRESENT = 0x80;

    interruptDescriptorTable[interruptNumber].handlerAddressLowBits = ((uint32_t)handler) & 0xFFFF;
    interruptDescriptorTable[interruptNumber].handlerAddressHighBits = (((uint32_t)handler) >> 16) & 0xFFFF;
    interruptDescriptorTable[interruptNumber].gdt_codeSegmentSelector = codeSegmentSelectorOffset;
    interruptDescriptorTable[interruptNumber].access = IDT_DESC_PRESENT | DescriptorType | ((DescriptorPrivilegeLebel&3) << 5);
    interruptDescriptorTable[interruptNumber].reserved = 0;

}

InterruptManager::InterruptManager(GlobalDescriptorTable* gdt)
: picMasterCommand(0x20),
  picMasterData(0x21),
  picSlaveCommand(0xA0),
  picSlaveData(0xA1)
{
    uint16_t CodeSegment = gdt->CodeSegmentSelector();
    const uint8_t IDT_INTERRUPT_GATE = 0xE;

    for(uint16_t i = 0; i<256; i++)
    {
        handlers[i] = 0;
        SetInterruptDescriptorTableEntry(i, CodeSegment, &InterruptIgnore, 0, IDT_INTERRUPT_GATE);
    }

    SetInterruptDescriptorTableEntry(0x20, CodeSegment, &HandleInterruptRequest0x00, 0, IDT_INTERRUPT_GATE);
    SetInterruptDescriptorTableEntry(0x21, CodeSegment, &HandleInterruptRequest0x01, 0, IDT_INTERRUPT_GATE);

    picMasterCommand.Write(0x11);
    picSlaveCommand.Write(0x11);

    picMasterData.Write(0x20);
    picSlaveData.Write(0x28);

    picMasterData.Write(0x04);
    picSlaveData.Write(0x02);

    picMasterData.Write(0x01);
    picSlaveData.Write(0x01);

    picMasterData.Write(0x00);
    picSlaveData.Write(0x00);

    InterruptDescriptorTablePointer idt;
    idt.size = 256 * sizeof(GateDescriptor) - 1;
    idt.base = (uint32_t)interruptDescriptorTable;
    asm volatile("lidt %0" : : "m" (idt));

}

InterruptManager::~InterruptManager()
{
}

void InterruptManager::Activate()
{
    if(ActiveInterruptManager != 0)
        ActiveInterruptManager->Deactivate();
    ActiveInterruptManager = this;
    asm("sti");
}

void InterruptManager::Deactivate()
{
    if(ActiveInterruptManager == this)
    {
        ActiveInterruptManager = 0;
        asm("cli");
    }
}

uint32_t InterruptManager::HandleInterrupt(uint8_t interruptNumebr, uint32_t esp)
{
    if(ActiveInterruptManager != 0)
        return ActiveInterruptManager->DoHandleInterrupt(interruptNumebr, esp);
    return esp;
}

uint32_t InterruptManager::DoHandleInterrupt(uint8_t interruptNumebr, uint32_t esp)
{
    if(handlers[interruptNumebr] != 0)
    {
        esp = handlers[interruptNumebr] -> HandleInterrupt(esp);
    }
    else if(interruptNumebr != 0x20)
    {
        char* foo = "UNHANDLED INTERRUPT 0x00";
        char* hex = "0123456789ABCDEF";
        foo[22] = hex[(interruptNumebr >> 4) & 0x0F];
        foo[23] = hex[interruptNumebr & 0x0F];
        printf(foo);
    }

    if(0x20 <= interruptNumebr && interruptNumebr < 0x30)
    {
        picMasterCommand.Write(0x20);
        if(0x28 <= interruptNumebr)
            picSlaveCommand.Write(0x20);

    }

    return esp;
}