FIRST (semi)WORKING PASS OF SERIAL DEBUGGING FINALLY!!!!!

framebuffer.c

@@ -39,9 +39,9 @@ void clear_fb(void) {
 
 // Takes the linear indexed position to move the cursos, if there is nothing at that position we should still have something there
 void fb_move_cursor(u16 position) {
-	serial_control(FB_CMD, FB_HIGH_CMD);
-	serial_control(FB_DATA, ((position >> 8) & 0x00ff) );
-	serial_control(FB_CMD, FB_LOW_CMD);
-	serial_control(FB_DATA, position & 0x00ff);
+	serialport_write_byte(FB_CMD, FB_HIGH_CMD);
+	serialport_write_byte(FB_DATA, ((position >> 8) & 0x00ff) );
+	serialport_write_byte(FB_CMD, FB_LOW_CMD);
+	serialport_write_byte(FB_DATA, position & 0x00ff);
 }
 

loader.s

@@ -9,7 +9,7 @@ CHECKSUM 		equ -MAGIC_NUMBER
 
 ; size in bytes of stack 
 KERNEL_STACK_SIZE	equ 4096
-extern test_write
+extern test_dispatcher
 
 section .text
 ; align all instructions to 4 byte boundary by the x86 instruction set law
@@ -20,7 +20,7 @@ align 4
 	dd CHECKSUM
 
 loader:
-	call test_write
+	call test_dispatcher
 
 .loop:
 	jmp .loop

ports.h

@@ -3,7 +3,7 @@
 #ifndef INCLUDE_IO_H
 #define INCLUDE_IO_H
 
-void serial_control(const u16, const u16);
+void serialport_write_byte(const u16, const u16);
 
 u8 serial_read_buffer(const u16);
 #endif /* INCLUDE_IO_H */

ports.s

@@ -1,34 +1,21 @@
 ; Helpers for frame buffer which pretty much have to to be 
 ; written in asm
 
-global serial_control
+global serialport_write_byte
 global serial_read_buffer
 
-serial_control:
-	;push ebp
-	;mov ebp, esp
-	;add esp, 0xc 	; ebp + 2 local vars (32-bit kernel)
-
+; write a byte  
+;serialport_write_byte
+serialport_write_byte:
 	mov al, [esp+8]
 	mov dx, [esp+4]
 	out dx, al
-
-	;mov esp, ebp
-	;pop ebp
 	ret
 
 ; Read byte from serial port
+;serialport_read_byte
 serial_read_buffer:
-	;push ebp
-	;mov ebp, esp
-	;push ebx
-
-	xor eax, eax
 	mov dx, [esp + 4] 	; grab the address of the targeted port
 	in al, dx 			; read byte from the port 
-
-	;mov esp, ebp
-	;pop ebx
-	;pop ebp
 	ret
 

serial.c

@@ -17,41 +17,68 @@ void serial_set_baud_rate(const u16 com_port, const u16 divisor) {
 	// send the higher 8 bits first
 	// send the lower 8 bits next
 
-	serial_control(SERIAL_LINE_COMMAND_PORT(com_port), 
+	serialport_write_byte(SERIAL_LINE_COMMAND_PORT(com_port), 
 			SERIAL_LINE_ENABLE);
 
-	serial_control(SERIAL_DATA_PORT(com_port), 
+	serialport_write_byte(SERIAL_DATA_PORT(com_port), 
 			(divisor>>8) & 0x00ff);
 
-	serial_control(SERIAL_DATA_PORT(com_port), 
+	serialport_write_byte(SERIAL_DATA_PORT(com_port), 
 			divisor & 0x00ff);
 }
 
 // Payload described above
 void serial_configure_line(const u16 line, const u8 payload) {
-	serial_control(SERIAL_LINE_COMMAND_PORT(line), payload);
+	serialport_write_byte(SERIAL_LINE_COMMAND_PORT(line), payload);
 }
 
+
 u8 serial_fifo_empty(const u16 com_port) {
-	// If the 5th bit is set then we know that the fifo queue is empty
-	return serial_read_buffer(SERIAL_LINE_STATUS_PORT(com_port)) & 0x20;
+	// we get back 0x20 if it is empty
+	return serial_read_buffer(SERIAL_LINE_STATUS_PORT(com_port)) & 
+		SERIAL_FIFO_EMPTY_CODE;
 }
 
-u64 serial_write(const s8* buffer, const u64 size) {
+u64 serial_write(const char* buffer, const u64 size) {
 	/*
 	 * Writes a given buffer to the com1 serial port for debugging in bochs
 	 */
 	u64 idx = 0;
-	serial_set_baud_rate(SERIAL_COM1_BASE, 1); // base baud rate
-	while(idx < size) {
-		if(serial_fifo_empty(SERIAL_COM1_BASE) == 0x20) {
-			serial_control(SERIAL_COM1_BASE, buffer[idx]);
-			idx++;
-		}
-		// otherwise we just wait until the queue is empty
-		else {
-			continue;
+	//serialport_write_byte(SERIAL_COM1_BASE + 1, 0x00);
+	serialport_write_byte(SERIAL_DATA_PORT_INT_EN(SERIAL_COM1_BASE), 
+			0x00);
+
+	//serialport_write_byte(SERIAL_COM1_BASE + 3, 0x80);
+	serialport_write_byte(SERIAL_LINE_COMMAND_PORT(SERIAL_COM1_BASE), 
+			SERIAL_LINE_ENABLE);
+
+	//serialport_write_byte(SERIAL_COM1_BASE + 0, 0x03);
+	serialport_write_byte(SERIAL_COM1_BASE, 
+			SERIAL_DEFAULT_LINE_CFG);
+
+	//serialport_write_byte(SERIAL_COM1_BASE + 1, 0x00);
+	serialport_write_byte(SERIAL_DATA_PORT_INT_EN(SERIAL_COM1_BASE),
+			0x00);
+	//serialport_write_byte(SERIAL_COM1_BASE + 3, 0x03);
+	serialport_write_byte(SERIAL_LINE_COMMAND_PORT(SERIAL_COM1_BASE), 
+			SERIAL_DEFAULT_LINE_CFG);
+
+	//serialport_write_byte(SERIAL_COM1_BASE + 2, 0xC7);
+	serialport_write_byte(SERIAL_FIFO_COMMAND_PORT(SERIAL_COM1_BASE),
+			SERIAL_DEFAULT_BUFFER_CFG);
+
+	//serialport_write_byte(SERIAL_COM1_BASE + 4, 0x0B);
+	serialport_write_byte(SERIAL_MODEM_COMMAND_PORT(SERIAL_COM1_BASE),
+			0x0B);
+
+	for(idx = 0; idx < size; idx++) {
+		serialport_write_byte(SERIAL_COM1_BASE, buffer[idx]);
+		/*
+		if(serial_fifo_empty(SERIAL_COM1_BASE == 0x02)) {
+			serialport_write_byte(SERIAL_COM1_BASE, buffer[idx]);
 		}
+		*/
 	}
 	return idx;
 }
+

serial.h

@@ -6,6 +6,7 @@
 #define SERIAL_COM1_BASE 				0x03F8
 
 #define SERIAL_DATA_PORT(base) 			(base)
+#define SERIAL_DATA_PORT_INT_EN(base)	(base+1)
 #define SERIAL_FIFO_COMMAND_PORT(base) 	(base+2)
 #define SERIAL_LINE_COMMAND_PORT(base) 	(base+3)
 #define SERIAL_MODEM_COMMAND_PORT(base) (base+4)
@@ -15,14 +16,16 @@
 
 // Default configurations for serial ports/lines/buffers etc.
 // Rational can be found here: https://littleosbook.github.io/#configuring-the-buffers
-#define SERIAL_DEFAULT_LINE_CFG 0X03
+#define SERIAL_DEFAULT_LINE_CFG 0x03
 #define SERIAL_DEFAULT_BUFFER_CFG 0xc7
 #define SERIAL_DEFAULT_MODEM_CFG 0x03
 
+#define SERIAL_FIFO_EMPTY_CODE 0x20
 void serial_set_baud_rate(const u16, const u16);
 
 void serial_configure_line(const u16, const u8); 
 
 u8 serial_fifo_empty(const u16);
 
-u64 serial_write(const s8* buffer, const u64 size);
+u64 serial_write(const char* buffer, const u64 size);
+

tests.c

@@ -5,9 +5,13 @@
 
 void test_write() {
 	clear_fb();
-	char* msg1 = "Imagine literally not \nwriting your own os";
-	serial_write((signed char*)msg1, strlen(msg1));
-	serial_write((signed char*)msg1, strlen(msg1));
-	//write(msg1, strlen(msg1));
+	char* msg1 = "Writing this to fbout\nOh yea and serial 0x3f8";
 	printf(msg1);
+	serial_write(msg1, strlen(msg1));
+	char* msg2 = "\nserial write has finished";
+	printf(msg2);
+}
+
+void test_dispatcher() {
+	test_write();
 }

tests.h

@@ -2,3 +2,4 @@
 #include "stlio.h"
 
 void test_write();
+void test_dispatcher();