console: Initial commit of simple framebuffer console output

include/console.h

@@ -22,5 +22,6 @@
 #define CONSOLE_H
 
 void console_init(struct fb *f);
+void console_putc(char c);
 
 #endif /* CONSOLE_H */

kernel/console.c

@@ -20,19 +20,23 @@
 
 #include <font.h>
 #include <framebuffer.h>
+#include <kmalloc.h>
+#include <print.h>
 
-#define CONSOLE_BUFFER_SIZE 16384
-char console_buffer[CONSOLE_BUFFER_SIZE];
-char console_output_buffer[CONSOLE_BUFFER_SIZE];
-char *console_buffer_p = console_buffer;
-struct fb *console_framebuffer = 0;
-struct font *console_font = 0;
-unsigned int chars_per_line = 0, lines = 0;
+char *console_buffer, *cb_first_line;
+struct fb *console_framebuffer;
+struct font *console_font;
+unsigned int chars_per_line, lines;
+unsigned int curr_char, curr_line;
 
-void console_char_to_fb(char c, unsigned int x, unsigned int y) {
+void console_char_to_fb(char c, unsigned int chr, unsigned int line) {
+	unsigned int x, y;
 	unsigned int cx, cy, bit = 0;
 	char *font_char = &console_font->data[console_font->bytes_per_char * (c - console_font->ascii_offset)];
 
+	x = chr * console_font->width;
+	y = line * console_font->height;
+
 	for (cy = 0; cy < console_font->height; cy++) {
 		for (cx = 0; cx < console_font->width; cx++) {
 			unsigned char on = font_char[bit / 8] & (1 << (bit % 8));
@@ -45,36 +49,103 @@ void console_char_to_fb(char c, unsigned int x, unsigned int y) {
 	}
 }
 
-void console_refresh_fb() {
+void console_redraw_fb() {
+	unsigned int cc, cl = 0;
+	char *c;
+
 	if (!console_framebuffer)
 		return;
+
+	for (c = cb_first_line; c < console_buffer + chars_per_line * lines; c += chars_per_line) {
+		char *d;
+		cc = 0;
+		for (d = c; d < c + chars_per_line; d++)
+			console_char_to_fb(*d, cc++, cl);
+		cl++;
 	}
 
-void console_clear() {
-	int i;
-	for (i = 0; i < CONSOLE_BUFFER_SIZE; i++) {
-		console_buffer[i] = 0;
+	for (c = console_buffer; c < cb_first_line; c += chars_per_line) {
+		char *d;
+		cc = 0;
+		for (d = c; d < c + chars_per_line; d++)
+			console_char_to_fb(*d, cc++, cl);
+		cl++;
 	}
 }
 
-void console_init(struct fb *f) {
-	console_clear();
-	console_refresh_fb();
-	console_font = font_get();
+void console_buffer_clear() {
+	char *c;
+	for (c = console_buffer; c < console_buffer + chars_per_line * lines; c++)
+		*c = ' ';
+	curr_char = 0;
+	curr_line = 0;
+}
+
+int console_init(struct fb *f) {
 	console_framebuffer = f;
-	chars_per_line = console_framebuffer->width / console_font->width;
+	console_font = font_get();
 	lines = console_framebuffer->height / console_font->height;
+	chars_per_line = console_framebuffer->width / console_font->width;
+	curr_line = 0;
+	curr_char = 0;
 
-	console_char_to_fb('A', 100, 100);
-	console_char_to_fb('E', 111, 100);
-	console_char_to_fb('D', 122, 100);
-	console_char_to_fb('R', 133, 100);
-	console_char_to_fb('I', 144, 100);
-	console_char_to_fb('X', 155, 100);
+	if (!(console_buffer = kmalloc(sizeof(char) * chars_per_line * lines))) {
+		print("Error: Failed to allocate memory for console buffer\n");
+		return -1;
+	}
+	cb_first_line = console_buffer;
+	
+	console_buffer_clear();
+	console_redraw_fb();
+
+	return 0;
+}
+
+void console_newline() {
+	char *c;
+
+	curr_line++;
+	curr_char = 0;
+	if (curr_line == lines) {
+		char *console_buffer_end = console_buffer + chars_per_line * lines;
+
+		//empty the current first line, since it will wrap around to the bottom
+		for (c = cb_first_line; c < cb_first_line + chars_per_line; c++)
+			*c = ' ';
+
+		cb_first_line += chars_per_line;
+		if (cb_first_line >= console_buffer_end)
+			cb_first_line = console_buffer;
+
+		curr_line = lines - 1;
+
+		console_redraw_fb();
+	}
 }
 
 void console_putc(char c) {
-	*console_buffer_p = c;
-	if (++console_buffer_p > console_buffer + CONSOLE_BUFFER_SIZE)
-		console_buffer_p = console_buffer;
+	char *console_buffer_end = console_buffer + chars_per_line * lines;
+	char *write_char_at;
+
+	switch (c) {
+		case '\n':
+			console_newline();
+			return;
+		case '\r':
+			curr_char = 0;
+			return;
+		default:
+			break;
+	}
+
+	if (curr_char + 1 > chars_per_line)
+		console_newline();
+
+	write_char_at = cb_first_line + chars_per_line * curr_line + curr_char;
+	if (write_char_at >= console_buffer_end)
+		write_char_at -= chars_per_line * lines;
+
+	*write_char_at = c;
+
+	console_char_to_fb(c, curr_char++, curr_line);
 }

kernel/start_kernel.c

@@ -31,15 +31,17 @@
 
 struct fb myfb;
 
-void video(void) {
-	unsigned int x, y;
+void print_console_logo() {
+	print_func(&console_putc, "                            _            _      _\n");
+	print_func(&console_putc, "                           / \\   ___  __| |_ __(_)_  __\n");
+	print_func(&console_putc, "                          / _ \\ / _ \\/ _` | '__| \\ \\/ /\n");
+	print_func(&console_putc, "                         / ___ \\  __/ (_| | |  | |>  <\n");
+	print_func(&console_putc, "                        /_/   \\_\\___|\\__,_|_|  |_/_/\\_\\\n\n");
+	print_func(&console_putc, "                        Copyright (C) 2012 - Aaron Lindsay\n");
+}
+
+void video_init(void) {
 	bcm2835_videocore_init(&myfb, 16);
-
-	for (y = 0; y < myfb.height; y++)
-		for (x = 0; x < myfb.width; x++)
-			fb_write_pixel(&myfb, x, y, 0x3f, 0x0, 0x6f);
-
-	console_init(&myfb);
 }
 
 void test_mm() {
@@ -142,7 +144,9 @@ int main(void) {
 
 	test_memory();
 
-	video();
+	video_init();
+	console_init(&myfb);
+	print_console_logo();
 
 	return 0;
 }