Added ports/serial.h header for serial console stuff

libk/ports/serial.c

@@ -0,0 +1,46 @@
+#include <ports/serial.h>
+#include <ports/io.h>
+#include <stdint.h>
+
+int setupSerial(uint32_t port) {
+    outb(port + 1, 0x00);   // Disable all interrupts
+    outb(port + 3, 0x80);   // Enable DLAB (set baud rate divisor)
+    outb(port + 0, 0x03);   // Set divisor to 3 (low byte) 38400 baud
+    outb(port + 1, 0x00);   //                  (high byte)
+    outb(port + 3, 0x03);   // 8 bits, no parity, one stop bit
+    outb(port + 2, 0xC7);   // Enable FIFO, clear them, with 14 byte threshold
+    outb(port + 4, 0x0B);   // IRQs enabled, RTS/DSR set
+    outb(port + 4, 0x1E);   // Set in loopback mode, test the serial chip
+    outb(port + 0, 0xAE);   // Test serial chip (send byte 0xAE and check if it returns)
+
+    if (inb(port + 0) != 0xAE) return 1;
+    outb(port + 4, 0x0F);   // non-loopback, IRQs enabled, OUT#1 and OUT#2 bits enabled
+
+    return 0;
+}
+
+int serialTransmitEmpty(uint32_t port) {
+    return inb(port + 5) & 0x20;
+}
+
+int serialRecieved(uint32_t port) {
+    return inb(port + 5) & 0x01;
+}
+
+void serialWrite(uint32_t port, char c) {
+    while (serialTransmitEmpty(port) == 0);
+    outb(port, c);
+}
+
+void serialPrint(uint32_t port, char* s) {
+    while (*s != '\0') {
+        if (*s == '\n') serialWrite(port, '\r');
+        serialWrite(port, *s++);
+    }
+}
+
+char serialRead(uint32_t port) {
+    while (serialRecieved(port));
+    return inb(port);
+}
+