drivers/vga/vga.c

   1 /*
   2         vga.c
   3         VGA Driver
   4         (C) 2014-2015 VOSystems.
   5 */
   6
   7 #include<Diverge/kstdio.h>
   8 #include<Diverge/diverge.h>
   9 #include<Diverge/types.h>
  10 #include<Diverge/string.h>
  11
  12 /*VGA Text Control*/
  13 static unsigned short *ch_vram;
  14 static unsigned short X,Y;
  15 static unsigned char attr;
  16
  17 #define SCREEN_START 0xb8000
  18 #define SCREEN_END   0xc0000
  19
  20 void ClearScreen(void)
  21 {
  22         ch_vram=(unsigned short*)0xb8000;
  23         X=0;Y=0;
  24         while(ch_vram<(unsigned short*)0xc0000)
  25         {
  26                 //*ch_vram++ =NULL;
  27                 *ch_vram++ = (((Black)<<8) | ' ');
  28         }
  29         ch_vram=(unsigned short*)0xb8000;
  30         AutoMoveCursol(X, Y);
  31         return;
  32 }
  33
  34 void init_vga(void)
  35 {
  36         strcpy(kstdout.sign,STDOUT_SIGN);
  37         kstdout.fp                      = NULL;
  38         kstdout.data_cnt        = NULL;
  39         kstdout.buf_addr        = NULL;
  40         kstdout.err_flag        = NULL;
  41         kstdout.file_desc       = 1;
  42
  43         strcpy(kstdin.sign,STDIN_SIGN);
  44         kstdin.fp                       = NULL;
  45         kstdin.data_cnt         = NULL;
  46         kstdin.buf_addr         = NULL;
  47         kstdin.err_flag         = NULL;
  48         kstdin.file_desc        = 0;
  49
  50         strcpy(kstderr.sign,STDERR_SIGN);
  51         kstderr.fp                      = NULL;
  52         kstderr.data_cnt        = NULL;
  53         kstderr.buf_addr        = NULL;
  54         kstderr.err_flag        = NULL;
  55         kstderr.file_desc       = 2;
  56
  57         fp_count=3;
  58
  59         stdout  = &kstdout;
  60         stdin   = &kstdin;
  61         stderr  = &kstderr;
  62
  63         DisplayColorChangeChar(White);
  64
  65         init_flag=true;
  66         ClearScreen();
  67 }
  68
  69 void DisplayOutputChar(const char ch)
  70 {
  71         if(ch=='\n'){
  72                 ch_vram+=(80-X);/*80 charactors * 2byte - X charactors * 2 byte*/
  73                 Y++;
  74                 X=0;
  75
  76         }else if(ch=='\t'){
  77                 *ch_vram++ = (((attr)<<8) | ' ');
  78                 *ch_vram++ = (((attr)<<8) | ' ');
  79                 X+=2;
  80
  81         }else if(ch=='\r'){
  82                 while(X>0)
  83                 {
  84                         *ch_vram-- = (unsigned short)NULL;
  85                         X--;
  86                 }
  87                 X=0;
  88
  89         }else if(ch=='\b'){
  90                 ch_vram--;
  91                 *ch_vram = (unsigned short)NULL;
  92                 X--;
  93
  94         }else if(ch==0x7f){
  95                 /*Delete*/
  96
  97         }else{
  98                 *ch_vram++ = (((attr)<<8) | ch);
  99                 X++;
 100
 101         }
 102
 103         AutoMoveCursol(X, Y);
 104
 105         if(X>=80){
 106                 X=0;
 107                 Y++;
 108         }
 109
 110         if(Y==25){
 111                 ShiftDisplayChar(1);
 112                 Y--;
 113                 ch_vram-=(80-X);
 114         }
 115
 116         return;
 117 }
 118
 119 void ShiftDisplayChar(unsigned int len)
 120 {
 121         unsigned short *sc1,*sc2;
 122         sc1=0xb8000;    sc2=0xb8000+(80*2);
 123         while(sc2<=0xc0000)*sc1++ = *sc2++;
 124         if(len>1){
 125                 len--;
 126                 ShiftDisplayChar(len);
 127         }
 128 }
 129
 130 void DisplayColorChangeChar(char att)
 131 {
 132         attr = att;
 133 }