92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
static const size_t VGA_WIDTH = 80;
|
|
static const size_t VGA_HEIGHT = 25;
|
|
|
|
/* Hardware text mode color constants. */
|
|
enum vga_color {
|
|
VGA_COLOR_BLACK = 0,
|
|
VGA_COLOR_BLUE = 1,
|
|
VGA_COLOR_GREEN = 2,
|
|
VGA_COLOR_CYAN = 3,
|
|
VGA_COLOR_RED = 4,
|
|
VGA_COLOR_MAGENTA = 5,
|
|
VGA_COLOR_BROWN = 6,
|
|
VGA_COLOR_LIGHT_GREY = 7,
|
|
VGA_COLOR_DARK_GREY = 8,
|
|
VGA_COLOR_LIGHT_BLUE = 9,
|
|
VGA_COLOR_LIGHT_GREEN = 10,
|
|
VGA_COLOR_LIGHT_CYAN = 11,
|
|
VGA_COLOR_LIGHT_RED = 12,
|
|
VGA_COLOR_LIGHT_MAGENTA = 13,
|
|
VGA_COLOR_LIGHT_BROWN = 14,
|
|
VGA_COLOR_WHITE = 15,
|
|
};
|
|
|
|
size_t terminal_row;
|
|
size_t terminal_column;
|
|
uint8_t terminal_color;
|
|
uint16_t* terminal_buffer;
|
|
|
|
uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
|
|
return fg | bg << 4;
|
|
}
|
|
|
|
uint16_t vga_entry(unsigned char uc, uint8_t color) {
|
|
return (uint16_t) uc | (uint16_t) color << 8;
|
|
}
|
|
|
|
size_t strlen(const char* str) {
|
|
size_t len = 0;
|
|
while (str[len])
|
|
len++;
|
|
return len;
|
|
}
|
|
|
|
void terminal_initialize(void) {
|
|
terminal_row = 0;
|
|
terminal_column = 0;
|
|
terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
|
|
terminal_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;
|
|
terminal_buffer[index] = vga_entry(' ', terminal_color);
|
|
}
|
|
}
|
|
}
|
|
|
|
void terminal_setcolor(uint8_t color) {
|
|
terminal_color = color;
|
|
}
|
|
|
|
void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) {
|
|
const size_t index = y * VGA_WIDTH + x;
|
|
terminal_buffer[index] = vga_entry(c, color);
|
|
}
|
|
|
|
void terminal_putchar(char c) {
|
|
if (c == '\n') {
|
|
terminal_column = 0;
|
|
terminal_row++;
|
|
return;
|
|
}
|
|
|
|
terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
|
|
if (++terminal_column == VGA_WIDTH) {
|
|
terminal_column = 0;
|
|
if (++terminal_row == VGA_HEIGHT)
|
|
terminal_row = 0;
|
|
}
|
|
}
|
|
|
|
void terminal_write(const char* data, size_t size) {
|
|
for (size_t i = 0; i < size; i++)
|
|
terminal_putchar(data[i]);
|
|
}
|
|
|
|
void terminal_writestring(const char* data) {
|
|
terminal_write(data, strlen(data));
|
|
} |