BarinkOS/src/kernel.c

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C
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#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "vga_colors.h"
#include "string.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 init_kterm () {
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_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 kterm_put (char c) {
kterm_putat ( c, kterm_color, kterm_column, kterm_row);
if(kterm_column++ == VGA_WIDTH ){
kterm_column = 0;
if(kterm_row++ == VGA_HEIGHT)
kterm_row = 0;
}
}
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 ){
kterm_write(data, strlen(data));
}
void kernel_main (void) {
/** initialize terminal interface */
init_kterm();
kterm_writestring("K: Hello world!\n");
}