blob: 11f3b9e2c76085c2bba5e65632cfff49bfff9bcb [file] [log] [blame]
#include "vga.h"
#include "io.h"
#include "log.h"
static uint cursor_x = 0;
static uint cursor_y = 0;
static ushort color = WHITE;
static ushort *fb = (ushort *)0xB8000;
static void move_cursor()
{
ushort loc = cursor_y * 80 + cursor_x;
outb(0x3d4, 14); // Setting high cursor byte
outb(0x3d4, loc >> 8);
outb(0x3d4, 15); // low byte
outb(0x3d4, loc & 0xff);
}
static void scroll()
{
ushort blank = ' ' | color << 8;
while (cursor_y >= 25) // end of line
{
// scroll everything up
memcpy(fb, &fb[80], 24 * 80 * 2);
for (int i = 24 * 80; i < 25 * 80; i++)
{
fb[i] = blank;
}
cursor_y--;
}
}
void vga_set_color(enum vga_colors fg, enum vga_colors bg)
{
color = (bg << 4) | fg & 0xf;
}
void vga_put(char c)
{
switch (c)
{
case '\b':
if (cursor_x > 0)
cursor_x--;
break;
case '\t':
cursor_x = (cursor_x + 8) & ~ 7;
break;
case '\n':
cursor_y++;
case '\r':
cursor_x = 0;
break;
default:
cursor_x++;
fb[cursor_y * 80 + cursor_x] = c | (color << 8);
}
if (cursor_x >= 80) // off screen
{
cursor_x = 0;
cursor_y++;
}
scroll();
move_cursor();
}
void vga_clear()
{
memset(fb, 0, 80 * 25 * 2);
cursor_x = 0;
cursor_y = 0;
move_cursor();
}
void vga_write(char *c)
{
for (int i = 0; c[i]; i++)
vga_put(c[i]);
}
void vga_putd(uint d)
{
char str[48];
memset(str, 0, 48);
uint i = 0;
while (d > 0 && i < 48) // should never be more than 48 digits anyway
{
str[i++] = (d % 10) + '0';
d /= 10;
}
for (uint j = i; j; j--)
{
vga_put(str[j - 1]);
}
}
static bool vga_put_nibble(uchar n, bool first)
{
if (first && n == 0)
return true;
if (n <= 9)
vga_put('0' + n);
else
vga_put('A' + n - 10);
return false;
}
void vga_putx(uint x)
{
bool first = true;
for (uint mask = 0xFF000000, shift = 24; mask; mask >>= 8, shift -= 8)
{
uchar byte = (x & mask) >> shift;
first = vga_put_nibble((byte & 0xf0) >> 8, first);
first = vga_put_nibble(byte & 0x0f, first);
}
}