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#include <purgatory.h>
#include "io.h"
#define VGABASE UNCACHED(0xb8000)
/* code based on i386 console code
* TODO add serial support
*/
#define MAX_YPOS 25
#define MAX_XPOS 80
unsigned long current_ypos = 1, current_xpos = 0;
static void putchar_vga(int ch)
{
int i, k, j;
if (current_ypos >= MAX_YPOS) {
/* scroll 1 line up */
for (k = 1, j = 0; k < MAX_YPOS; k++, j++) {
for (i = 0; i < MAX_XPOS; i++) {
writew(readw(VGABASE + 2*(MAX_XPOS*k + i)),
VGABASE + 2*(MAX_XPOS*j + i));
}
}
for (i = 0; i < MAX_XPOS; i++)
writew(0x720, VGABASE + 2*(MAX_XPOS*j + i));
current_ypos = MAX_YPOS-1;
}
if (ch == '\n') {
current_xpos = 0;
current_ypos++;
} else if (ch != '\r') {
writew(((0x7 << 8) | (unsigned short) ch),
VGABASE + 2*(MAX_XPOS*current_ypos +
current_xpos++));
if (current_xpos >= MAX_XPOS) {
current_xpos = 0;
current_ypos++;
}
}
}
void putchar(int ch)
{
putchar_vga(ch);
}
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