Interrupts + basic keyboard driver

1 files changed, 65 insertions, 0 deletions

diff --git a/src/kernel/keyboard/pic.c b/src/kernel/keyboard/pic.c
index 0c81629..e1b4fb3 100644
--- a/src/kernel/keyboard/pic.c
+++ b/src/kernel/keyboard/pic.c
@@ -1 +1,66 @@
 #include "asm.h"
+#include <stdint.h>
+#define PIC1 0x20
+#define PIC2 0xA0
+#define PIC1_COMMAND PIC1
+#define PIC1_DATA (PIC1 + 1)
+#define PIC2_COMMAND PIC2
+#define PIC2_DATA (PIC2 + 1)
+
+void PIC_init(int offset1, int offset2) {
+    uint8_t a1, a2;
+
+    a1 = inb(PIC1_DATA);
+    a2 = inb(PIC2_DATA);
+
+    outb(PIC1_COMMAND, 0x11); // Init PIC1
+    io_wait();
+    outb(PIC2_COMMAND, 0x11); // Init PIC2
+    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);
+    io_wait();
+    outb(PIC2_DATA, 2);
+    io_wait();
+    outb(PIC1_DATA, 0x01);
+    io_wait();
+    outb(PIC2_DATA, 0x01);
+    io_wait();
+
+    outb(PIC1_DATA, a1); // restore saved masks.
+    outb(PIC2_DATA, a2);
+}
+
+void IRQ_mask(uint8_t line) {
+    uint16_t port = line < 8 ? PIC1_DATA : PIC2_DATA;
+    line = line > 8 ? line - 8 : line;
+    uint8_t val = inb(port) | (1 << line);
+    outb(port, val);
+}
+
+void IRQ_unmask(uint8_t line) {
+    uint16_t port = line < 8 ? PIC1_DATA : PIC2_DATA;
+    line = line > 8 ? line - 8 : line;
+    uint8_t val = inb(port) & ~(1 << line);
+    outb(port, val);
+}
+
+void PIC_disable(void) {
+    outb(PIC1_DATA, 0xff);
+    outb(PIC2_DATA, 0xff);
+}
+
+uint16_t PIC_irr(void) {
+    outb(PIC1_COMMAND, 0x0a);
+    outb(PIC2_COMMAND, 0x0a);
+    return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
+}
+
+uint16_t PIC_isr(void) {
+    outb(PIC1_COMMAND, 0x0b);
+    outb(PIC2_COMMAND, 0x0b);
+    return (inb(PIC2_COMMAND) << 8) | inb(PIC1_COMMAND);
+}