thomas/mittos64-old
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[INTERRUPTS] IRQs and the Programmable Interrupt Controller

Browse Source
This commit is contained in:
Thomas Lovén
2016-11-09 21:16:29 +01:00
parent 8b2e58b6b1
commit b7c0de7ea5
3 changed files with 105 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
kernel/interrupts/pic.c Normal file
View File

@@ -0,0 +1,65 @@
#include <stdint.h>
#include <ports.h>
#include <debug.h>
#include <int.h>
#define MPIC_CMD 0x0020
#define MPIC_DATA 0x0021
#define SPIC_CMD 0x00A0
#define SPIC_DATA 0x00A1
#define PIC_CMD_INIT 0x10
#define PIC_CMD_EXTRA 0x01
#define PIC_CMD_8086 0x01
#define PIC_CMD_EOI 0x20
void pic_init()
{
// Send initialize command
outb(MPIC_CMD, PIC_CMD_INIT | PIC_CMD_EXTRA);
outb(SPIC_CMD, PIC_CMD_INIT | PIC_CMD_EXTRA);
// Remap offsets
outb(MPIC_DATA, INT_IRQ0);
outb(SPIC_DATA, INT_IRQ8);
// Setup slave PIC
outb(MPIC_DATA, 0x04);
outb(SPIC_DATA, 0x02);
// Extra environment data
outb(MPIC_DATA, PIC_CMD_8086);
outb(SPIC_DATA, PIC_CMD_8086);
// Mask all interrupts
outb(MPIC_DATA, 0xFF);
outb(SPIC_DATA, 0xFF);
}
void pic_ack(uint8_t irq)
{
if(irq >= 8)
outb(SPIC_CMD, PIC_CMD_EOI);
outb(MPIC_CMD, PIC_CMD_EOI);
}
void pic_mask(uint8_t irq)
{
if(irq >= 8)
{
outb(SPIC_DATA, inb(SPIC_DATA) | 1 << (irq-8));
} else {
outb(MPIC_DATA, inb(MPIC_DATA) | 1 << irq);
}
}
void pic_unmask(uint8_t irq)
{
if(irq >= 8)
{
outb(SPIC_DATA, inb(SPIC_DATA) & ~(1 << (irq-8)));
} else {
outb(MPIC_DATA, inb(MPIC_DATA) & ~(1 << irq));
}
}