#include <stdio.h>
// This program reads an ORCA bit file and converts it to a binary file to
// be used by the XBERT.  For the Pbert, this conversion is a simple
// bit reversal for each byte (after stripping of the 0x41 byte header).
// For the remote modules (TBERT, RBERT), 12 bits are packed into a 36-bit
// serial word.  Each data bit has a start bit (1) and a stop bit (0).

void Set_ext(char *Name, char *Ext, int Flag)    // Set file extension
{ char *P= 0;                                    // If (Flag) force it
  while (*Name)
  { if (*Name=='/' || *Name=='\\') P=0;
    if (*Name=='.') P= Name;
    ++Name; }
  if (Flag==0 && P) return;     // Extension already exists and no Flag
  if (P==0) P=Name;             // No extension, add to end
  while ((*P++ = *Ext++) !=0);  // Copy
}

int main (int Argc, char *Argv[])
{ unsigned long D,L;
  int I,B;
  char Name[128];
  FILE *In, *Out;
  if (Argc < 2)
  { printf("Usage:\n bit2brt [-r] file[.bit]\n");
    printf(" Converts ORCA bit files for use by XBERT\n");
    printf(" Use -r option for remote modules\n");
    return(-1); }
  for (I=0; (Name[I]= Argv[Argc-1][I])!=0; ++I);

  Set_ext(Name,".bit",0);
  if ((In= fopen(Name,"rb")) == NULL)
  { printf("Couldn't open bit file [%s] for input.\n",Name);
    return(-1); }
  fseek(In,0x41,0);        // Point to first data byte
  Set_ext(Name,".brt",1);  // Force .brt extension
  if ((Out= fopen(Name,"wb")) == NULL)
  { printf("Couldn't open brt file [%s] for output.\n",Name);
    return(-1); }

  if (Argc == 2)           // If no -r option on command line
  { while (fread(&B,1,1,In) > 0)
    { B= ((B<<1)&0xaa) | ((B>>1)&0x55);   // Reverse bits...
      B= ((B<<2)&0xcc) | ((B>>2)&0x33);   // Swap 2-bits
      B= (B<<4) | (B>>4);                 // Swap nibbles
      fwrite(&B,1,1,Out);
  } }
  else                    // if -r then prepare to be sent via serial port
#define SetBit(Bi,Bo) if (D&(1L<<Bi)) L |= (1L<<Bo);
  { while (!feof(In))
    { D=0xffffffffL;
      fread(&D,1,3,In);   // Read 24 bits and convert to two 36-bit things
      L= 0x24924924L;     // Fill in start and stop bits
      SetBit( 7,0);  SetBit( 6,3);  SetBit( 5,6);  SetBit( 4,9);
      SetBit( 3,12); SetBit( 2,15); SetBit( 1,18); SetBit( 0,21);
      SetBit(15,24); SetBit(14,27); SetBit(13,30);
      I= (D&(1L<<12))? 3 : 1;
      fwrite(&L,4,1,Out); fwrite(&I,2,1,Out);   // Write first 36-bit thing
      L= 0x24924924L;     // Fill in start and stop bits
      SetBit(11,0);  SetBit(10,3);  SetBit( 9,6);  SetBit( 8,9);
      SetBit(23,12); SetBit(22,15); SetBit(21,18); SetBit(20,21);
      SetBit(19,24); SetBit(18,27); SetBit(17,30);
      I= (D&(1L<<16))? 3 : 1;
      fwrite(&L,4,1,Out); fwrite(&I,2,1,Out);   // Write second thing
  } }
  return(0);
}