banan-os/kernel/arch/i386/tty.c

103 lines
2.0 KiB
C

#include <kernel/tty.h>
#include "vga.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
static const size_t VGA_WIDTH = 80;
static const size_t VGA_HEIGHT = 25;
static uint16_t* const VGA_MEMORY = (uint16_t*)0xB8000;
static size_t terminal_row;
static size_t terminal_col;
static uint8_t terminal_color;
static uint16_t* terminal_buffer;
void terminal_putentryat(unsigned 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_clear(void)
{
for (size_t y = 0; y < VGA_HEIGHT; y++)
for (size_t x = 0; x < VGA_WIDTH; x++)
terminal_putentryat(' ', terminal_color, x, y);
}
void terminal_initialize(void)
{
terminal_row = 0;
terminal_col = 0;
terminal_color = vga_entry_color(VGA_COLOR_WHITE, VGA_COLOR_BLACK);
terminal_buffer = VGA_MEMORY;
terminal_clear();
}
void terminal_setcolor(uint8_t color)
{
terminal_color = color;
}
void terminal_scroll_line(size_t line)
{
for (size_t x = 0; x < VGA_WIDTH; x++)
{
const size_t index = line * VGA_WIDTH + x;
terminal_buffer[index - VGA_WIDTH] = terminal_buffer[index];
}
}
void terminal_clear_line(size_t line)
{
for (size_t x = 0; x < VGA_WIDTH; x++)
terminal_putentryat(' ', terminal_color, x, line);
}
void terminal_putchar(char c)
{
if (c == '\n')
{
terminal_col = 0;
terminal_row++;
}
else
{
terminal_putentryat(c, terminal_color, terminal_col, terminal_row);
terminal_col++;
}
if (terminal_col == VGA_WIDTH)
{
terminal_col = 0;
terminal_row++;
}
if (terminal_row == VGA_HEIGHT)
{
for (size_t line = 1; line < VGA_HEIGHT; line++)
terminal_scroll_line(line);
terminal_clear_line(VGA_HEIGHT - 1);
terminal_col = 0;
terminal_row = VGA_HEIGHT - 1;
}
}
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)
{
size_t len = 0;
while (data[len])
len++;
terminal_write(data, len);
}