1 files changed, 37 insertions, 0 deletions
diff --git a/driver/serial.c b/driver/serial.c
new file mode 100644
index 0000000..f402d0c
--- /dev/null
+++ b/driver/serial.c
@@ -0,0 +1,37 @@
+#define FOOLOS_MODULE_NAME "serial"
+// https://wiki.osdev.org/Serial_Ports
+
+#define PORT 0x3f8   /* COM1 */
+ 
+#include "lib/logger/log.h"
+
+void serial_init() {
+
+   x86_outb(PORT + 1, 0x00);    // Disable all interrupts
+   x86_outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
+   x86_outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
+   x86_outb(PORT + 1, 0x00);    //                  (hi byte)
+   x86_outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+   x86_outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+   x86_outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+
+   log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"COM 1 - initialized");
+}
+
+int serial_received() {
+   return x86_inb(PORT + 5) & 1;
+}
+ 
+char serial_read() {
+   while (serial_received() == 0);
+   return x86_inb(PORT);
+}
+
+int is_transmit_empty() {
+   return x86_inb(PORT + 5) & 0x20;
+}
+ 
+void serial_write(char a) {
+   while (is_transmit_empty() == 0);
+   x86_outb(PORT,a);
+}