/*
output.c
Copyright © 2009 William Astle

This file is part of LWLINK.

LWLINK is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.


Actually output the binary
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>

#include "lwlink.h"

// this prevents warnings about not using the return value of fwrite()
// and, theoretically, can be replaced with a function that handles things
// better in the future
#define writebytes(s, l, c, f)	do { int r; r = fwrite((s), (l), (c), (f)); } while (0)

void do_output_decb(FILE *of);
void do_output_raw(FILE *of);

void do_output(void)
{
	FILE *of;
	
	of = fopen(outfile, "wb");
	if (!of)
	{
		fprintf(stderr, "Cannot open output file %s: ", outfile);
		perror("");
		exit(1);
	}
	
	switch (outformat)
	{
	case OUTPUT_DECB:
		do_output_decb(of);
		break;
	
	case OUTPUT_RAW:
		do_output_raw(of);
		break;
	
	default:
		fprintf(stderr, "Unknown output format doing output!\n");
		exit(111);
	}
	
	fclose(of);
}

void do_output_decb(FILE *of)
{
	int sn;
	unsigned char buf[5];
	
	for (sn = 0; sn < nsects; sn++)
	{
		if (sectlist[sn].ptr -> flags & SECTION_BSS)
		{
			// no output for a BSS section
			continue;
		}
		if (sectlist[sn].ptr -> codesize == 0)
		{
			// don't generate output for a zero size section
			continue;
		}
		// write a preamble
		buf[0] = 0x00;
		buf[1] = sectlist[sn].ptr -> codesize >> 8;
		buf[2] = sectlist[sn].ptr -> codesize & 0xff;
		buf[3] = sectlist[sn].ptr -> loadaddress >> 8;
		buf[4] = sectlist[sn].ptr -> loadaddress & 0xff;
		writebytes(buf, 1, 5, of);
		writebytes(sectlist[sn].ptr -> code, 1, sectlist[sn].ptr -> codesize, of);
	}
	// write a postamble
	buf[0] = 0xff;
	buf[1] = 0x00;
	buf[2] = 0x00;
	buf[3] = linkscript.execaddr >> 8;
	buf[4] = linkscript.execaddr & 0xff;
	writebytes(buf, 1, 5, of);
}

void do_output_raw(FILE *of)
{
	int nskips = 0;		// used to output blanks for BSS inline
	int sn;
	
	for (sn = 0; sn < nsects; sn++)
	{
		if (sectlist[sn].ptr -> flags & SECTION_BSS)
		{
			// no output for a BSS section
			nskips += sectlist[sn].ptr -> codesize;
			continue;
		}
		while (nskips > 0)
		{
			// the "" is not an error - it turns into a single NUL byte!
			writebytes("", 1, 1, of);
			nskips--;
		}
		writebytes(sectlist[sn].ptr -> code, 1, sectlist[sn].ptr -> codesize, of);
	}
}