refactoring

1 files changed, 80 insertions, 0 deletions

diff --git a/kernel/src/arch/i686/pic.c b/kernel/src/arch/i686/pic.c
new file mode 100644
index 0000000..f5d0f94
--- /dev/null
+++ b/kernel/src/arch/i686/pic.c
@@ -0,0 +1,80 @@
+#include <sys.h>
+#include <print.h>
+#include <arch/i686/pic.h>
+#include <arch/i686/asm.h>
+
+#define PIC1_COMMAND_PORT 0x20
+#define PIC1_DATA_PORT 0x21
+#define PIC2_COMMAND_PORT 0xA0
+#define PIC2_DATA_PORT 0xA1
+
+void pic_remap(void) {
+	char a1 = inb(PIC1_DATA_PORT);
+	char a2 = inb(PIC2_DATA_PORT);
+	// control word 1
+	// 0x11: initialize, enable ICW4
+	outb(PIC1_COMMAND_PORT, 0x11);
+	io_wait();
+	outb(PIC2_COMMAND_PORT, 0x11);
+	io_wait();
+	// control word 2
+	// interrupt offset
+	outb(PIC1_DATA_PORT, PIC_REMAP_OFFSET);
+	io_wait();
+	outb(PIC2_DATA_PORT, PIC_REMAP_OFFSET + 8);
+	io_wait();
+	// control word 3
+	// primary pic: set which pin secondary is connected to
+	// (pin 2)
+	outb(PIC1_DATA_PORT, 0x04);
+	io_wait();
+	outb(PIC2_DATA_PORT, 2);
+	io_wait();
+	// control word 3
+	// 0x01: enable 8086 mode
+	outb(PIC1_DATA_PORT, 0x01);
+	io_wait();
+	outb(PIC2_DATA_PORT, 0x01);
+	io_wait();
+	// clear data registers
+	outb(PIC1_DATA_PORT, a1);
+	outb(PIC2_DATA_PORT, a2);
+}
+
+void pic_mask(int irq) {
+	uint8_t port;
+	if(irq < 8) {
+		port = PIC1_DATA_PORT;
+	} else {
+		irq -= 8;
+		port = PIC2_DATA_PORT;
+	}
+	uint8_t mask = inb(port);
+	outb(port, mask | (1 << irq));
+}
+
+void pic_unmask(int irq) {
+	uint8_t port;
+	if(irq < 8) {
+		port = PIC1_DATA_PORT;
+	} else {
+		irq -= 8;
+		port = PIC2_DATA_PORT;
+	}
+	uint8_t mask = inb(port);
+	outb(port, mask & ~(1 << irq));
+}
+
+void pic_disable(void) {
+	outb(PIC1_DATA_PORT, 0xff);
+	io_wait();
+	outb(PIC2_DATA_PORT, 0xff);
+	io_wait();
+}
+
+void pic_eoi(int irq) {
+	if(irq >= 8) {
+		outb(PIC2_COMMAND_PORT, 0x20);
+	}
+	outb(PIC1_COMMAND_PORT, 0x20);
+}