/*
TOHEX.C   Written in BDS C

  ED GANGER
  605 Laurel Ave
  Johnson City, TN 37601
  (615)929-7053

This Program changes a file from .REL format to .HEX format
See the L80 Reference Manual for details.

*/
#include <bdscio.h>
/*
** link tags 
*/
#define SPECIAL		0
#define ABSOLUTE	0
#define PROG_REL	1
#define DAT_REL		2
#define COMM_REL	3
/*
** subfields of SPECIAL
*/
/*
** These have a name field only
*/
#define ENTRY_SYM	0
#define SELECT_COM	1
#define PROGNAME	2
/* undefined		3 */
/* undefined		4 */
/*
** Value field and name field:
*/
#define COMM_SIZE	5
#define CHAIN_EXT	6
#define DEFINE_ENTRY	7
/* undefined		8 */
/*
** Value field only:
*/
#define EXT_PLUS_OFFS	9
#define DATA_SIZE	10
#define ORIGIN		11
#define CHAIN_ADDR	12
#define PROG_SIZE	13
#define END_MOD		14
/*
** No fields:
*/
#define ENDFILE		15

#define stderr 4


FILE infile,outfile;
char inbyte,bitnum;
char line[100];
int lineptr;
int here;
int cksum;

/*
** grab next bit from file
*/
nextbit()
{
if (! bitnum )
	{
	bitnum = 8;
	inbyte = getc(infile);
	}
return ((inbyte >> --bitnum)&0x01);
}
/*
** grab next N bits from file and return packed into an integer
*/
bits(n)
int n;
{
int bitval,i;

bitval=0;
for (i=0;i<n;i++)
	bitval = (bitval+bitval)+nextbit();
return bitval;
}

/*
** process fields for a tag bit of one -
*/
onetag()
{
switch (bits(2)){
	case SPECIAL:
		special();
		break;
	case PROG_REL:		/* program relative is defined as absolute */
		gen (bits(8));
		gen (bits(8));
		break;
	default:
		error ("Invalid Type");
		exit();
		}
}

/*
** add this byte to output buffer.
** if line is full, flush it
*/
gen(val)
int val;
{
cksum += val;
sprintf(&line[lineptr],"%02X",val);
lineptr += 2;
line[lineptr]=0 ;
if (lineptr >= 0x40)
	flshx();
}

/*
** flush a bunch of bytes in INTEL HEX FORMAT
*/
flshx()
{
if (lineptr)
	{
	cksum += (lineptr >> 1);
	cksum += (here & 0xff);
	cksum += here >> 8;
	cksum = (-cksum) & 0xff;
	printf(":%02X%04X00%s%02X\n" ,lineptr >>1 ,here, line,cksum);
	fprintf(outfile,":%02X%04X00%s%02X\n" ,lineptr >>1 ,here, line,cksum);
	cksum = 0;
	here += lineptr >> 1;
	lineptr = 0;
	*line=0;
	}
}
/*
** print error message and abort
*/
error(string)
char *string;
{
fprintf(stderr,"%s\n",string);
exit();
}
/*
** do special tag
*/
special()
{
int tag,i,j;
char name[9];
int val;
char *text;

tag = bits(4);

switch (tag){
	case ENTRY_SYM:
		getname(name);
		printf("Entry = %s\n",name);
		return;
	case PROGNAME:
		getname(name);
		printf("Program is %s\n",name);
		return;
	case DEFINE_ENTRY:
		val = getval();
		getname(name);
		printf ( "Entry of %s at %04X\n",name,val);
		return;
	case DATA_SIZE:
		val = getval();
		printf ("Data Size: %04X\n",val);
		return;	
	case ORIGIN:
		flshx();
		here = getval();
		printf ("NEW ORIGIN: %04X\n",here);
		return;	
	case PROG_SIZE:
		val = getval();
		printf ("Program Size: %04X\n",val);
		return;	
	case END_MOD:
		printf("Module End ... Bye\n");
		flshx();
		fprintf(outfile,":00000000FF\n%c",CPMEOF);
		printf(":00000000FF\n%c",CPMEOF);
		fclose(outfile);
		exit();
	}
}
/*
** get a name string
*/
getname(name)
char *name;
{
int i,j;

j=bits(3);
if (!j) j=8;
for (i=0;i<j;i++)
	*name++ = bits(8);
*name = 0;
}
/*
** get a 16 bit value
*/
getval()
{
int i;
bits(2);
i=bits(8);
i += (bits(8)<<8);
return i;
}





main(argc,argv)
int argc;
char *argv[];
{
int i;
if (argc != 3)
	error("Usage: TOHEX INFILE.REL OUTFILE.HEX");
if(fopen(argv[1],infile) == ERROR)
	error("Cant Open Input");
if(fcreat(argv[2],outfile)==ERROR)
	error ("Cant Open Output"); 
while (1)
	{
	if (bits(1))
		onetag();
	else
		gen(bits(8));
	}
}