/*  Program to copy a ROM pgm from SRAM to ROM  */
/*  To properly execute this pgm:
       - make this (fmu) pgm with an srec start @ $80000 
       - make the rom pgm with an srec start @ $0
       - load fmu pgm into cpu32 thru bdm with 0 offset
       - load rom pgm into cpu32 thru bdm with $a0000 offset
       - clear the area from $90000 to $90050 (so cam monitor flags)
       - go $80000
       - monitor for finished by checking flag=2 & fcount=0 (no errors)
       - take care after running this pgm to not reset, else
    will again download to rom. As soon as finished, download
    some other program in the space assigned for this program. */
      
    struct variables { 
      unsigned short int *start_addr;
      unsigned short int data;
      int rom_addr,addr,flag,no_words,i,j,t,
	 setw,fcount;
      unsigned short int data_rdbk[50];
    };
    #define vp (*(struct variables *)0x090000)
      
fmu()
{
  vp.start_addr = (short int *)0x0A0000;   /* start addr of data or
		   pgm in sram which is to be copied into rom  */
  vp.rom_addr = 0x000000;     /* rom start addr */
  vp.no_words = 1000;         /* max no of words to be copied */
  vp.flag = 0;
  vp.fcount = 0;
  erase();
  vp.flag = 1;
  for (vp.i = 0;vp.i < vp.no_words;vp.i++)  {
    vp.addr = vp.rom_addr + 2*vp.i;
    vp.data = *(vp.start_addr + vp.i);
    program_word();
    if(vp.setw == 0)    /* try 1 more time-need for 1st byte */
      program_word();
    if(vp.setw == 0)
      vp.fcount++;       /* error count */
  }
  vp.flag = 2;
  while(1);
       
}
erase()
{

    /* chip erase:
         shift addresses left 1 bit since a0 not connected to rom;
	 send unlock codes to both rom banks (1st 2 bytes go to
	 1st rom bank via d0-7, 2nd pair to 2nd rom bank via d8-15 */
    *(unsigned volatile short int *)(0x5555<<1)=0xaaaa;
    *(unsigned volatile short int *)(0x2aaa<<1)=0x5555;
    *(unsigned volatile short int *)(0x5555<<1)=0x8080;
    *(unsigned volatile short int *)(0x5555<<1)=0xaaaa;
    *(unsigned volatile short int *)(0x2aaa<<1)=0x5555;
    *(unsigned volatile short int *)(0x5555<<1)=0x1010;

    /* Poll til chip erased (d7=1; d15=1) */
    while (!((*(unsigned volatile short int *)0x0) & 0x8080));

  return;
}

program_word()
{

  vp.setw = 0;
  /*  Shift addresses left 1 bit since a0 not connected to rom;
	 send unlock codes to both rom banks (1st 2 bytes go to
	 1st rom bank via d0-7, 2nd pair to 2nd rom bank via d8-15 */
  *(unsigned volatile short int *)(0x5555<<1)=0xaaaa;
  *(unsigned volatile short int *)(0x2aaa<<1)=0x5555;
  *(unsigned volatile short int *)(0x5555<<1)=0xa0a0;
  /* don't shift address of data, since cpu won't shift when tries to read rom */
  *(unsigned volatile short int *)(vp.addr)=vp.data;

  /* Poll til word is set in rom */
  for (vp.t = 0; vp.t < 100000; vp.t++) {
    if(vp.t < 47)vp.data_rdbk[vp.t] = *(unsigned volatile short int *)vp.addr;
    /* next 2 shoul show when toggling stops */
    vp.data_rdbk[47] = *(unsigned volatile short int *)vp.addr;
    vp.data_rdbk[48] = *(unsigned volatile short int *)vp.addr;
    if(vp.t == 49)vp.data_rdbk[vp.t] = *(unsigned volatile short int *)vp.addr;
    if((*(unsigned volatile short int *)vp.addr) == vp.data ) {
      vp.setw = 1;        /* successfully set word */
      return;
    }
  }
  return;
}