aedrix-kernel/kernel/console.c

/*
    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>

    This file is part of Aedrix.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <font.h>
#include <framebuffer.h>
#include <kmalloc.h>
#include <print.h>

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 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));
			if (on)
				fb_write_pixel(console_framebuffer, x + cx, y + cy, 0xff, 0xff, 0xff);
			else
				fb_write_pixel(console_framebuffer, x + cx, y + cy, 0x00, 0x00, 0x00);
			bit++;
		}
	}
}

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++;
	}

	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_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;
	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;

	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();
	}
}

int console_putc(char c) {
	char *console_buffer_end = console_buffer + chars_per_line * lines;
	char *write_char_at;

	switch (c) {
		case '\n':
			console_newline();
			return 0;
		case '\r':
			curr_char = 0;
			return 0;
		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);

	return 0;
}