2 files changed, 63 insertions, 0 deletions
diff --git a/arch/i386/kernel/pic.h b/arch/i386/kernel/pic.h
new file mode 100644
index 0000000..da4a2ee
--- /dev/null
+++ b/arch/i386/kernel/pic.h
@@ -0,0 +1,16 @@
+#ifndef PIC_H
+#define PIC_H
+
+#include <stdint.h>
+
+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;
+}
+
+#endif
diff --git a/arch/i386/kernel/serial.c b/arch/i386/kernel/serial.c
new file mode 100644
index 0000000..20bd8f9
--- /dev/null
+++ b/arch/i386/kernel/serial.c
@@ -0,0 +1,47 @@
+#include <kernel/serial.h>
+#include <kernel/string.h>
+#include <stddef.h>
+#include "pic.h"
+
+#define PORT 0x3f8
+
+int serial_init(void) {
+        outb(PORT + 1, 0x00);
+        outb(PORT + 3, 0x80);
+        outb(PORT + 0, 0x03);
+        outb(PORT + 1, 0x00);
+        outb(PORT + 3, 0x03);
+        outb(PORT + 2, 0xC7);
+        outb(PORT + 4, 0x0B);
+        outb(PORT + 4, 0x1E);
+        outb(PORT + 0, 0xAE);
+
+        if (inb(PORT + 0) != 0xAE)
+                return -1;
+
+        outb(PORT + 4, 0x0F);
+        return 0;
+}
+
+int serial_recieved(void) {
+        return inb(PORT + 5) & 1;
+}
+
+char read_serial(void) {
+        while (serial_recieved() == 0);
+        return inb(PORT);
+}
+
+int is_transmit_empty(void) {
+        return inb(PORT + 5) & 0x20;
+}
+
+void write_serial(char a) {
+        while (is_transmit_empty() == 0);
+        outb(PORT, a);
+}
+
+void serial_writestring(const char *str) {
+        for (size_t i = 0; i < strlen(str); i++)
+                write_serial(str[i]);
+}