arch: i386: add support for 8259 PIC

Add support for the 8259 programmable interrupt controller.

Signed-off-by: Danny Holman <dholman@gymli.xyz>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/i386/include/kernel/pic.h b/arch/i386/include/kernel/pic.h
new file mode 100644
index 0000000..c3ede4f
--- /dev/null
+++ b/arch/i386/include/kernel/pic.h
@@ -0,0 +1,45 @@
+#ifndef I386_PIC_H
+#define I386_PIC_H
+
+#include <stdint.h>
+
+#define PIC1            0x20
+#define PIC2            0x28
+#define PIC1_COMMAND    PIC1
+#define PIC1_DATA       (PIC1+1)
+#define PIC2_COMMAND    PIC2
+#define PIC2_DATA       (PIC2+1)
+
+#define ICW1_ICW4       0x01
+#define ICW1_SINGLE     0x02
+#define ICW1_INTERVAL4  0x04
+#define ICW1_LEVEL      0x08
+#define ICW1_INIT       0x10
+
+#define ICW4_8086       0x01
+#define ICW4_AUTO       0x02
+#define ICW4_BUF_SLAVE  0x08
+#define ICW4_BUF_MASTER 0x0C
+#define ICW4_SFNM       0x10
+
+static inline void outb(uint16_t port, uint8_t value) {
+        asm volatile("outb %0, %1" : : "a"(value), "Nd"(port));
+}
+
+static inline uint8_t inb(uint16_t port) {
+        uint8_t ret;
+        asm volatile("inb %1, %0" : "=a"(ret) : "Nd"(port));
+        return ret;
+}
+
+static inline void io_wait(void) {
+        outb(0x80, 0);
+}
+
+void pic_eoi(unsigned char irq);
+void pic_remap(void);
+
+void irq_set_mask(uint8_t irq);
+void irq_clear_mask(uint8_t irq);
+
+#endif