int kmain()
{
fb_write_cell(0, 'A', FB_GREEN, FB_DARK_GRAY);
char *hello = "Hello, World!";
write_out(hello, 13);
return 0xDEADBABE;
}
/** fb_write_word:
* Writes out word
*/
void fb_write_word() {
// prints out 'ABCDE' in white on black font
unsigned char black = 0x7;
unsigned char grey = 0x0;
unsigned int addr = 0;
fb_write_cell(addr, 'T', grey, black);
addr += 2;
fb_write_cell(addr, 'O', grey, black);
addr += 2;
fb_write_cell(addr, 'N', grey, black);
addr += 2;
fb_write_cell(addr, 'Y', grey, black);
addr += 2;
fb_write_cell(addr, '!', grey, black);
addr += 2;
}
int fb_write(char *buf) {
while(*buf != 0) {
fb_move_cursor(currPos);
fb_write_cell(2 * currPos++, *buf, FB_GREEN, FB_DARK_GREY);
buf++;
}
return currPos;
}
// Write the contents of a buffer of length len to the screen. Should
// automatically advance the cursor after a character has been written, and
// scroll if necessary.
void fb_puts(char *buf, unsigned int len) {
unsigned int i;
for (i = 0; i < len; ++i) {
fb_write_cell(cursor_pos, buf[i], curr_color & 0xF0, curr_color & 0x0F);
cursor_pos = (cursor_pos + 1) % FB_NUM_CELLS;
}
fb_move_cursor();
}
/** write:
* Writes a character buffer
*
* @param buf The character buffer
* @param len The length of the buffer
*/
void write(char *buf, unsigned int len)
{
unsigned short i;
for(i = 0; i < len; i++)
{
fb_write_cell(fb_current_pos, buf[i], 0, 15);
fb_current_pos += 2;
}
}
// Write a null-terminated string to the monitor.
void fb_write(char *str) {
unsigned int i;
i = 0;
while (str[i] != '\0') {
fb_write_cell(cursor_pos, str[i++], curr_color & 0xF0, curr_color & 0x0F);
cursor_pos = (cursor_pos + 1) % FB_NUM_CELLS;
}
fb_move_cursor();
}
void fb_write_char(const char c) {
if (c == '\n') {
fb_curr_pos += (ROW_WIDTH-(fb_curr_pos%ROW_WIDTH));
} else {
fb_write_cell(fb_curr_pos, c, FB_LIGHTGREY, FB_BLACK);
fb_curr_pos+=2;
}
fb_set_cursor_pos(fb_curr_pos/2);
}
void fb_clear() {
unsigned int i, k;
for (i = 0; i < ROW_HEIGHT; ++i) {
for (k = 0; k < ROW_WIDTH; k+=2) {
fb_write_cell((i*ROW_HEIGHT)+k, '\0', FB_LIGHTGREY, FB_BLACK);
}
}
fb_set_cursor_pos(0);
fb_curr_pos = 0;
}
/** fb_clear:
* Clears the framebuffer
*/
void fb_clear() {
unsigned char black = 0x0;
unsigned int addr = 0;
unsigned int addr_max = 80 * 50;
unsigned int i = 0;
for (i = addr; i < addr_max; i += 2) {
fb_write_cell(i, ' ', black, black);
}
}
/* Write a single character to the terminal */
void fb_write_char(char c)
{
if (c == '\t') {
if (fb_cursor_column > 72) {
c = '\n';
} else {
fb_cursor_column += 8 - (fb_cursor_column % 8);
return;
}
}
/* Handle newline characters */
if (c == '\n') {
fb_cursor_column = 0;
fb_cursor_row++;
return;
}
/* Wrap text by bumping the row when the column hits maximum width */
if (fb_cursor_column == VGA_WIDTH) {
fb_cursor_column = 0;
fb_cursor_row++;
}
if (fb_cursor_row == VGA_HEIGHT) {
// Shift everyone up to make a new row available
for (size_t row = 1; row < VGA_HEIGHT; row++) {
for (size_t column = 0; column < VGA_WIDTH; column++) {
const size_t entry = row * VGA_WIDTH + column;
framebuffer[entry - VGA_WIDTH] = framebuffer[entry];
framebuffer[entry] = make_vga_entry(' ', COLOR_LIGHT_GREY, COLOR_BLACK);
}
}
fb_cursor_column = 0;
fb_cursor_row--;
}
fb_write_cell(c, COLOR_LIGHT_GREY, COLOR_BLACK, fb_cursor_row, fb_cursor_column);
fb_cursor_column++;
}
int fb_write(char *buf, unsigned int len) {
unsigned int i;
for(i=0; i<len; i++) {
/* Write character at position i */
fb_write_cell(2*__fb_present_pos, buf[i], (unsigned char)0, (unsigned char)15);
fb_move_cursor(__fb_present_pos + 1);
/* If __fb_present_pos goes off the screen, move everything one line up */
if(__fb_present_pos == FRAMEBUFFER_WIDTH * FRAMEBUFFER_HEIGHT) {
fb_move_cursor((FRAMEBUFFER_HEIGHT-1)*FRAMEBUFFER_WIDTH);
int j;
for(j=0; j<2*FRAMEBUFFER_WIDTH*(FRAMEBUFFER_HEIGHT-1); j++) {
__fb[j] = __fb[j + FRAMEBUFFER_WIDTH*2];
}
for(j=j; j<2*FRAMEBUFFER_WIDTH*FRAMEBUFFER_HEIGHT; j++) {
__fb[j] = 0;
}
}
}
return len;
}
// Write a single character to the screen from wherever the cursor is.
void fb_putc(char c) {
fb_write_cell(cursor_pos, c, curr_color & 0xF0, curr_color & 0x0F);
cursor_pos = (cursor_pos + 1) % FB_NUM_CELLS;
fb_move_cursor();
}