BarinkOS/src/kernel/arch/i386/tty/kterm.c

236 lines
5.0 KiB
C

#include "kterm.h"
static const size_t VGA_WIDTH = 80;
static const size_t VGA_HEIGHT = 25;
size_t kterm_row;
size_t kterm_column;
uint8_t kterm_color;
uint16_t* kterm_buffer;
static inline uint8_t vga_entry_color( enum vga_color fg, enum vga_color bg) {
return fg | bg << 4;
}
static inline uint16_t vga_entry (unsigned char uc, uint8_t color) {
return (uint16_t) uc | (uint16_t) color << 8;
}
void kterm_init () {
kterm_row = 0;
kterm_column = 0;
kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
kterm_buffer = (uint16_t*) 0xB8000;
for (size_t y = 0; y < VGA_HEIGHT; y++ ){
for( size_t x = 0; x < VGA_WIDTH; x++){
const size_t index = y * VGA_WIDTH + x;
kterm_buffer[index] = vga_entry(' ', kterm_color);
}
}
}
void kterm_resetcolor(){
kterm_color = vga_entry_color ( VGA_COLOR_LIGHT_GREY , VGA_COLOR_BLACK);
}
void kterm_setcolor(uint8_t color){
kterm_color = color;
}
void kterm_putat (char c, uint8_t color, size_t x, size_t y ) {
const size_t index = y * VGA_WIDTH + x;
kterm_buffer[index] = vga_entry(c, color);
}
void enable_cursor (uint8_t start_cursor , uint8_t end_cursor ){
outb(0x3D4, 0x0A);
outb(0x3D5, (inb(0x3D5) & 0xC0) | start_cursor);
outb(0x3D4, 0x0B);
outb(0x3D5, (inb(0x3D5) & 0xE0) | end_cursor);
}
void disable_cursor()
{
outb(0x3D4, 0x0A);
outb(0x3D5, 0x20);
}
void update_cursor(int x, int y){
uint16_t pos = y * VGA_WIDTH + x;
outb(0x3D4, 0x0F);
outb(0x3D5, (uint8_t) (pos & 0xFF));
outb(0x3D4, 0x0E);
outb(0x3D5, (uint8_t) ((pos >> 8) & 0xFF));
}
uint16_t get_cursor_position(){
uint16_t pos = 0;
outb(0x3D4, 0x0F);
pos |= inb(0x3D5);
outb(0x3D4, 0x0E);
pos |= ((uint16_t) inb(0x3D5)) << 8;
return pos;
}
int get_cursor_x (uint16_t cursor_pos) {
return cursor_pos % VGA_WIDTH;
}
int get_cursor_y (uint16_t cursor_pos ) {
return cursor_pos / VGA_WIDTH;
}
/**
* With the help from:
* https://whiteheadsoftware.dev/operating-systems-development-for-dummies/
**/
void kterm_scrollup(){
size_t i ;
for(i=0; i < (VGA_WIDTH * VGA_HEIGHT - VGA_WIDTH); i++)
kterm_buffer[i] = kterm_buffer[i+VGA_WIDTH];
for( i=0; i< VGA_WIDTH; i++)
kterm_buffer[(VGA_HEIGHT -1) * VGA_WIDTH + i ] = vga_entry(' ', kterm_color);
}
void kterm_put (char c) {
if(++kterm_column == VGA_WIDTH || c == '\n' ) {
update_cursor(kterm_column , kterm_row);
kterm_column = 0;
if(kterm_row == VGA_HEIGHT-1 ) {
kterm_scrollup();
} else {
kterm_row ++;
}
}
if ( c == '\r'){
kterm_column = 0;
return;
}
if(c == '\n') return;
kterm_putat ( c, kterm_color, kterm_column, kterm_row);
}
void kterm_write(const char* data, size_t size) {
for(size_t i = 0; i < size; i++){
kterm_put(data[i]);
}
}
void kterm_writestring(const char* data ){
// AS_KERNEL();
kterm_write(data, strlen(data));
}
static void itoa (char *buf, int base, int d) {
char *p = buf;
char *p1, *p2;
unsigned long ud = d;
int divisor = 10;
if ( base == 'd' && d < 0){
*p++ = '-';
buf++;
ud = -d;
} else if (base == 'x'){
divisor = 16;
}
do {
int remainder = ud % divisor;
*p++ = (remainder < 10 ) ? remainder + '0' : remainder + 'a' -10;
} while(ud /= divisor);
/*terminate buf*/
*p =0;
p1 = buf;
p2 = p -1;
while (p1 < p2)
{
char tmp = *p1;
*p1 = *p2;
*p2 = tmp;
p1++;
p2--;
}
}
void printf ( const char *format, ...) {
char **arg = (char **)&format;
int c;
char buf[20];
arg++;
while ((c = *format++) != 0){
if( c != '%')
kterm_put(c);
else{
char *p, *p2;
int pad0 = 0, pad = 0;
c = *format++;
if(c =='0'){
pad0 = 1;
c = *format++;
}
if ( c >= '0' && c <= '9'){
pad = c - '0';
c = *format++;
}
switch (c)
{
case 'd':
kterm_writestring("Not implemented!!");
break;
case 'u':
break;
case 'x':
itoa(buf, c, *((int *) arg++));
p = buf;
goto string;
break;
case 's':
p = *arg++;
if(!p)
p = "(null)";
string:
for (p2 = p; *p2; p2++);
for (; p2 < p + pad; p2++)
kterm_put(pad0 ? '0': ' ');
while (*p)
kterm_put(*p++);
break;
default:
kterm_put(*((int *)arg++));
break;
}
}
}
}