I've zeroed out the interrupt mask register, and i've tested that my software interrupts are working (i put an int3 breakpoint in my code), and i even mapped every interrupt to the same function in my idt to see if the irq's were being sent to the wrong interrupt, but i'm still getting nothing. What am i doing wrong?
I'm testing to see if i get IRQ's by typing on my keyboard.
pic_remap function:
Code: Select all
#define PIC1 0x20 /* IO base address for master PIC */
#define PIC2 0xA0 /* IO base address for slave PIC */
#define PIC1_COMMAND PIC1
#define PIC1_DATA (PIC1+1)
#define PIC2_COMMAND PIC2
#define PIC2_DATA (PIC2+1)
#define ICW1_ICW4 0x01 /* ICW4 (not) needed */
#define ICW1_SINGLE 0x02 /* Single (cascade) mode */
#define ICW1_INTERVAL4 0x04 /* Call address interval 4 (8) */
#define ICW1_LEVEL 0x08 /* Level triggered (edge) mode */
#define ICW1_INIT 0x10 /* Initialization - required! */
#define ICW4_8086 0x01 /* 8086/88 (MCS-80/85) mode */
#define ICW4_AUTO 0x02 /* Auto (normal) EOI */
#define ICW4_BUF_SLAVE 0x08 /* Buffered mode/slave */
#define ICW4_BUF_MASTER 0x0C /* Buffered mode/master */
#define ICW4_SFNM 0x10 /* Special fully nested (not) */
void PIC_remap(unsigned char offset1, unsigned char offset2)
{
// unsigned char a1, a2;
// a1 = inb(PIC1_DATA); // save masks
// a2 = inb(PIC2_DATA);
outb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4); // starts the initialization sequence (in cascade mode)
io_wait();
outb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4);
io_wait();
outb(PIC1_DATA, offset1); // ICW2: Master PIC vector offset
io_wait();
outb(PIC2_DATA, offset2); // ICW2: Slave PIC vector offset
io_wait();
outb(PIC1_DATA, 4); // ICW3: tell Master PIC that there is a slave PIC at IRQ2 (0000 0100)
io_wait();
outb(PIC2_DATA, 2); // ICW3: tell Slave PIC its cascade identity (0000 0010)
io_wait();
outb(PIC1_DATA, ICW4_8086);
io_wait();
outb(PIC2_DATA, ICW4_8086);
io_wait();
// outb(PIC1_DATA, a1); // restore saved masks.
// outb(PIC2_DATA, a2);
outb(PIC1_DATA, 0); // zero out the pic mask
outb(PIC2_DATA, 0);
}
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void idt_init()
{
idt_location.offset = (unsigned long) &idt;
idt_location.size = (sizeof(struct IDT_ENTRY) * 8) - 1;
unsigned char *zero_idt = (unsigned char*) idt;
for(unsigned long i = 0; i < idt_location.size; i++)
zero_idt[i] = 0;
unsigned char flags = 0x8E; // standard 32 bit interrupt gate
unsigned long offset = 0;
for(int i = 0; i < 256; i++)
{
switch(i)
{
case 0:
{
offset = (unsigned long) isr_divide_by_zero;
}
break;
case 1:
{
offset = (unsigned long) isr_debugger;
}
break;
case 2:
{
offset = (unsigned long) isr_nmi;
}
break;
case 3:
{
offset = (unsigned long) isr_breakpoint;
}
break;
case 4:
{
offset = (unsigned long) isr_overflow;
}
break;
case 5:
{
offset = (unsigned long) isr_bounds;
}
break;
case 6:
{
offset = (unsigned long) isr_invalid_opcode;
}
break;
case 7:
{
offset = (unsigned long) isr_coprocessor_not_avail;
}
break;
case 8:
{
offset = (unsigned long) isr_double_fault;
}
break;
case 9:
{
offset = (unsigned long) isr_coprocessor_segment_overrun;
}
break;
case 10:
{
offset = (unsigned long) isr_invalid_tss;
}
break;
case 11:
{
offset = (unsigned long) isr_segment_not_present;
}
break;
case 12:
{
offset = (unsigned long) isr_stack_fault;
}
break;
case 13:
{
offset = (unsigned long) isr_general_protection_fault;
}
break;
case 14:
{
offset = (unsigned long) isr_page_fault;
}
break;
case 15:
{
offset = (unsigned long) isr_reserved;
}
break;
case 16:
{
offset = (unsigned long) isr_math_fault;
}
break;
case 17:
{
offset = (unsigned long) isr_alignment_check;
}
break;
case 18:
{
offset = (unsigned long) isr_machine_check;
}
break;
case 19:
{
offset = (unsigned long) isr_simd_floating_point_exception;
}
break;
case 0x21: // keyboard
{
offset = (unsigned long) isr_keyboard;
}
break;
default:
continue;
}
idt[i].offset_low = (offset & 0xFFFF);
idt[i].offset_high = ((offset >> 16) & 0xFFFF);
idt[i].selector = 0x08;
idt[i].zero = 0;
idt[i].type_attr = flags;
}
install_idt();
}
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void kernel_main()
{
k_clearscreen(DEFAULT_TEXT);
idt_init(); // install interrupt descriptor table
PIC_remap(0x20, 0x28);
k_putstring("PIC Initialized.\n", DEFAULT_TEXT);
}
This is frustrating.