kernel/arch/x86/tty/tty.c

   1 #include <io.h>
   2 #include <tty.h>
   3 #include <stdint.h>
   4 #include <time/i8254.h>
   5
   6 #define VGA_WIDTH 80
   7 #define VGA_HEIGHT 25
   8
   9 volatile char *video_memory = (char *) 0xB8000; /* VGA VRAM starts at 0xB8000 */
  10
  11 static int cursor_x = 0; /* keep track of where cursor is */
  12 static int cursor_y = 0;
  13
  14 char *hex_chars = "0123456789ABCDEF";
  15
  16 void screen_clear(void)
  17 {
  18         int x, y;
  19         for ( y = 0; y < VGA_HEIGHT; y++ ) {
  20                 for ( x = 0; x < VGA_WIDTH; x++ ) {
  21                         video_memory[(y * VGA_WIDTH + x) * 2 + 1] = VGA_COLOR_LIGHT_GRAY;
  22                         video_memory[(y * VGA_WIDTH + x) * 2] = ' ';
  23                 }
  24         }
  25
  26         cursor_x = 0;
  27         cursor_y = 0;
  28 }
  29
  30 void scroll_up(void)
  31 {
  32         int x, y;
  33         for ( y = 1; y < VGA_HEIGHT; y++ ) {
  34                 for ( x = 0; x < VGA_WIDTH; x++ ) {
  35                         video_memory[((y - 1) * VGA_WIDTH + x) * 2] = video_memory[(y * VGA_WIDTH + x) * 2];
  36                 }
  37         }
  38         for ( x = 0; x < VGA_WIDTH; x++ ) {
  39                 video_memory[((VGA_HEIGHT - 1) * VGA_WIDTH + x) * 2] = ' ';
  40         }
  41         cursor_y = VGA_HEIGHT - 1;
  42 }
  43
  44 void kprint(const char *string, uint8_t color)
  45 {
  46         kprintc('[', 0);
  47         kprintdec(ticks / (1193182 / 65536));
  48         kprints("] ", 0);
  49         kprints(string, color);
  50 }
  51
  52 void kprints(const char *string, uint8_t color)
  53 {
  54         char next_char;
  55         uint8_t vga_misc_output;
  56         uint16_t crtc_port;
  57         next_char = *string;
  58
  59         while ( next_char != 0 ) {
  60                 if ( next_char == '\n') { cursor_x = 0; cursor_y++; }
  61                 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; }
  62                 if ( cursor_x >= VGA_WIDTH ) { cursor_x = 0; cursor_y++; }
  63                 if ( cursor_y >= VGA_HEIGHT ) { scroll_up(); }
  64                 next_char = *++string;
  65         }
  66
  67         vga_misc_output = inb(0x3CC);
  68         if (vga_misc_output & 0x1 == 0) {
  69                 crtc_port = 0x3B4;
  70         } else {
  71                 crtc_port = 0x3D4;
  72         }
  73
  74         outb(crtc_port, 0xE);
  75         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) >> 8);
  76         outb(crtc_port, 0xF);
  77         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) & 0xFF);
  78 }
  79
  80 void kprintc(const char character, uint8_t color)
  81 {
  82         uint8_t vga_misc_output;
  83         uint16_t crtc_port;
  84
  85         if ( character == '\n') { cursor_x = 0; cursor_y++; }
  86         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; }
  87         if ( cursor_x >= VGA_WIDTH ) { cursor_x = 0; cursor_y++; }
  88         if ( cursor_y >= VGA_HEIGHT ) { scroll_up(); }
  89
  90         vga_misc_output = inb(0x3CC);
  91         if (vga_misc_output & 0x1 == 0) {
  92                 crtc_port = 0x3B4;
  93         } else {
  94                 crtc_port = 0x3D4;
  95         }
  96
  97         outb(crtc_port, 0xE);
  98         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) >> 8);
  99         outb(crtc_port, 0xF);
 100         outb(crtc_port + 1, (cursor_y * VGA_WIDTH + cursor_x) & 0xFF);
 101
 102 }
 103
 104 void kprintb(uint8_t byte)
 105 {
 106         uint8_t temp;
 107         temp = byte >> 4;
 108         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 109         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 110         temp = byte & 0xF;
 111         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 112 }
 113
 114 void kprintw(uint16_t word)
 115 {
 116         uint8_t temp;
 117         temp = word >> 12;
 118         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 119         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 120         temp = (word >> 8) & 0xF;
 121         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 122         temp = (word >> 4) & 0xF;
 123         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 124         temp = word & 0xF;
 125         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 126 }
 127
 128 void kprintd(uint32_t dword)
 129 {
 130         uint8_t temp;
 131         temp = dword >> 28;
 132         kprint("0x", VGA_COLOR_LIGHT_GRAY);
 133         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 134         temp = (dword >> 24) & 0xF;
 135         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 136         temp = (dword >> 20) & 0xF;
 137         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 138         temp = (dword >> 16) & 0xF;
 139         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 140         temp = (dword >> 12) & 0xF;
 141         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 142         temp = (dword >> 8) & 0xF;
 143         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 144         temp = (dword >> 4) & 0xF;
 145         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 146         temp = dword & 0xF;
 147         kprintc(hex_chars[temp], VGA_COLOR_LIGHT_GRAY);
 148 }
 149
 150 int kprintdec(uint32_t num)
 151 {
 152         char buffer[11];
 153         int digits = 10;
 154
 155         /* TODO: make an actual memset function to use instead of this */
 156         for (int i=0; i<11; i++) {
 157                 buffer[i] = 0;
 158         }
 159
 160         /* handle edge case */
 161         if (num==0) {
 162                 *buffer = '0';
 163                 goto print;
 164         }
 165
 166         /* put the numbers in the buffer */
 167         for (int i=9; i>0 && num>0; i--) {
 168                 uint8_t currdigit = num%10;
 169                 buffer[i] = currdigit+'0';
 170                 num /= 10;
 171         }
 172
 173         /* shift the array as much as needed */
 174         while (*buffer == '\0') {
 175                 digits--;
 176                 for (int i=0; i<9; i++) {
 177                         buffer[i] = buffer[i+1];
 178                 }
 179         }
 180
 181         /* zero out any leftovers */
 182         if (digits < 10) {
 183                 for (int i=digits; i<10; i++) {
 184                         buffer[i] = '\0';
 185                 }
 186         }
 187
 188 print:
 189         kprints(buffer, 0);
 190         return digits;
 191 }