cleaning up asm stuff and improving docs

1 files changed, 13 insertions, 7 deletions

diff --git a/driver/serial.c b/driver/serial.c
index 1a36bf5..6e6a4bb 100644
--- a/driver/serial.c
+++ b/driver/serial.c
@@ -1,10 +1,13 @@
 #define FOOLOS_MODULE_NAME "serial"
 #include "serial.h"
 
-#define PORT 0x3f8   /* COM1 */
+#include "asm/x86.h" // provides x86_inb() and x86_outb()
 
-void serial_init() {
+/** COM1 Port */
+static const PORT=0x3f8;
 
+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
@@ -13,23 +16,26 @@ void serial_init() {
    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() {
+static uint32_t serial_received()
+{
    return x86_inb(PORT + 5) & 1;
 }
  
-char serial_read() {
+uint8_t serial_read()
+{
    while (serial_received() == 0);
    return x86_inb(PORT);
 }
 
-int is_transmit_empty() {
+static uint32_t is_transmit_empty()
+{
    return x86_inb(PORT + 5) & 0x20;
 }
  
-void serial_write(char a) {
+void serial_write(uint8_t a)
+{
    while (is_transmit_empty() == 0);
    x86_outb(PORT,a);
 }