kernel/arch/x86/tty/tty.c

   1 #include <io.h>
   2 #include <tty.h>
   3 #include <stdint.h>
   4
   5 #define VGA_WIDTH 80
   6 #define VGA_HEIGHT 25
   7
   8 volatile char *video_memory = (char *) 0xB8000; /* VGA VRAM starts at 0xB8000 */
   9
  10 static int cursor_x = 0; /* keep track of where cursor is */
  11 static int cursor_y = 0;
  12
  13 char *hex_chars = "0123456789ABCDEF";
  14
  15 void screen_clear(void)
  16 {
  17         int x, y;
  18         for ( y = 0; y < VGA_HEIGHT; y++ ) {
  19                 for ( x = 0; x < VGA_WIDTH; x++ ) {
  20                         video_memory[(y * VGA_WIDTH + x) * 2 + 1] = VGA_COLOR_LIGHT_GRAY;
  21                         video_memory[(y * VGA_WIDTH + x) * 2] = ' ';
  22                 }
  23         }
  24
  25         cursor_x = 0;
  26         cursor_y = 0;
  27 }
  28
  29 void scroll_up(void)
  30 {
  31         int x, y;
  32         for ( y = 1; y < VGA_HEIGHT; y++ ) {
  33                 for ( x = 0; x < VGA_WIDTH; x++ ) {
  34                         video_memory[((y - 1) * VGA_WIDTH + x) * 2] = video_memory[(y * VGA_WIDTH + x) * 2];
  35                 }
  36         }
  37         for ( x = 0; x < VGA_WIDTH; x++ ) {
  38                 video_memory[((VGA_HEIGHT - 1) * VGA_WIDTH + x) * 2] = ' ';
  39         }
  40         cursor_y = VGA_HEIGHT - 1;
  41 }
  42
  43 void kprint(const char *string, uint8_t color)
  44 {
  45         char next_char;
  46         uint8_t vga_misc_output;
  47         uint16_t crtc_port;
  48         next_char = *string;
  49
  50         while ( next_char != 0 ) {
  51                 if ( next_char == '\n') { cursor_x = 0; cursor_y++; }
  52                 else { video_memory[(cursor_y * VGA_WIDTH + cursor_x) * 2] = next_char; video_memory[((cursor_y * VGA_WIDTH + cursor_x++) * 2)+ 1] = color != 0 ? color : VGA_COLOR_LIGHT_GRAY; }
  53                 if ( cursor_x >= VGA_WIDTH ) { cursor_x = 0; cursor_y++; }
  54                 if ( cursor_y >= VGA_HEIGHT ) { scroll_up(); }
  55                 next_char = *++string;
  56         }
  57
  58         vga_misc_output = inb(0x3CC);
  59         if (vga_misc_output & 0x1 == 0) {
  60                 crtc_port = 0x3B4;
  61         } else {
  62                 crtc_port = 0x3D4;
  63         }
  64
  65         outb(crtc_port, 0xE);
  66         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) >> 8);
  67         outb(crtc_port, 0xF);
  68         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) & 0xFF);
  69 }
  70
  71 void kprintc(const char character, uint8_t color)
  72 {
  73         uint8_t vga_misc_output;
  74         uint16_t crtc_port;
  75
  76         if ( character == '\n') { cursor_x = 0; cursor_y++; }
  77         else { video_memory[(cursor_y * VGA_WIDTH + cursor_x) * 2] = character; video_memory[((cursor_y * VGA_WIDTH + cursor_x++) * 2)+ 1] = color != 0 ? color : VGA_COLOR_LIGHT_GRAY; }
  78         if ( cursor_x >= VGA_WIDTH ) { cursor_x = 0; cursor_y++; }
  79         if ( cursor_y >= VGA_HEIGHT ) { scroll_up(); }
  80
  81         vga_misc_output = inb(0x3CC);
  82         if (vga_misc_output & 0x1 == 0) {
  83                 crtc_port = 0x3B4;
  84         } else {
  85                 crtc_port = 0x3D4;
  86         }
  87
  88         outb(crtc_port, 0xE);
  89         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) >> 8);
  90         outb(crtc_port, 0xF);
  91         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) & 0xFF);
  92
  93 }
  94
  95 void kprintb(uint8_t byte)
  96 {
  97         uint8_t temp;
  98         temp = byte >> 4;
  99         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 100         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 101         temp = byte & 0xF;
 102         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 103 }
 104
 105 void kprintw(uint16_t word)
 106 {
 107         uint8_t temp;
 108         temp = word >> 12;
 109         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 110         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 111         temp = (word >> 8) & 0xF;
 112         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 113         temp = (word >> 4) & 0xF;
 114         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 115         temp = word & 0xF;
 116         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 117 }
 118
 119 void kprintd(uint32_t dword)
 120 {
 121         uint8_t temp;
 122         temp = dword >> 28;
 123         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 124         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 125         temp = (dword >> 24) & 0xF;
 126         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 127         temp = (dword >> 20) & 0xF;
 128         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 129         temp = (dword >> 16) & 0xF;
 130         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 131         temp = (dword >> 12) & 0xF;
 132         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 133         temp = (dword >> 8) & 0xF;
 134         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 135         temp = (dword >> 4) & 0xF;
 136         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 137         temp = dword & 0xF;
 138         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 139 }