smunge.c

MIPS下的boottloader yamon 的源代码

#include	<stdio.h>
/* #include	<process.h>*/
#include	<string.h>

FILE			*in, *out;
char			recbuf[256];
int				reclen;
unsigned long	recaddr;
unsigned long	offset = 0;
int				do_swizzle32 = 0;
int				do_swap = 0;
int 			do_swizzle16=0;

int		load_srec(char *line)
{
	int		i, c;

	if( line[0] != 's' && line[0] != 'S' )
		return 0;

	switch(line[1])
	{
		case '1':
			sscanf(line+2,"%2x%4x",&reclen,&recaddr);
			line += 8;
			reclen -= 2;
			break;

		case '2':
			sscanf(line+2,"%2x%6x",&reclen,&recaddr);
			line += 10;
			reclen -= 3;
			break;

		case '3':
			sscanf(line+2,"%2x%8x",&reclen,&recaddr);
		   	line += 12;
			reclen -= 4;
			break;

		default:
			return 0;
	}

	reclen -= 1;

	for( i = 0; i < reclen; ++i )
	{
		sscanf(line,"%2x",&c);
		recbuf[i] = c;
		line += 2;
	}
	return 1;
}

void	dump_srec()
{
	int				cksm, i;
	unsigned long	addr = recaddr + offset;
	int				len = reclen + 5;

	cksm = ((len >> 8) & 0x0ff) + (len & 0x00ff);
	cksm += (addr >> 24) & 0x0ff;
	cksm += (addr >> 16) & 0x0ff;
	cksm += (addr >> 8) & 0x0ff;
	cksm += addr & 0x0ff;
	fprintf(out,"S3%02X%08X",len,addr);
	for( i = 0; i < reclen; ++i )
	{
		cksm += recbuf[i] & 0x00ff;
		fprintf(out,"%02X",recbuf[i] & 0x0ff);
	}
	fprintf(out,"%02X\n",(~cksm) & 0x0ff);
}

void	swizzle16()
{
	int		c, i;

	for( i = 0; i < reclen; i += 2 )
	{
		c = recbuf[i];
		recbuf[i] = recbuf[i + 1];
		recbuf[i + 1] = c;
	}
}

void	swizzle32()
{
	int		c, i;

	for( i = 0; i < reclen; i += 4 )
	{
		c = recbuf[i];
		recbuf[i] = recbuf[i + 3];
		recbuf[i + 3] = c;
		c=recbuf[i+1];
		recbuf[i+1]=recbuf[i+2];
		recbuf[i+2]=c;
	}
}

void	swap_halfwords()
{
	int		c, i;

	for( i = 0; i < reclen; i += 4 )
	{
		c = recbuf[i];
		recbuf[i] = recbuf[i + 2];
		recbuf[i + 2] = c;
		c = recbuf[i + 1];
		recbuf[i + 1] = recbuf[i + 3];
		recbuf[i + 3] = c;
	}
}

void	mungeline(char *s)
{
	if( load_srec(s) )
	{
		if( do_swizzle32 )
			swizzle32();

		if ( do_swizzle16 )
			swizzle16();

		if ( do_swap )
		 	swap_halfwords();
		
		dump_srec();
	}
	else
		fputs(s,out);
}

void	smunge(char *filename)
{
	char	buf[132];

	in = fopen(filename,"r");
	if( in == NULL )
	{
		fprintf(stderr,"Can't open input file %s\n",filename);
		exit(1);
	}

	strncpy(buf,filename,120);
	strcat(buf,".m");
	out = fopen(buf,"w");
	if( out == NULL )
	{
		fprintf(stderr,"Can't open output file %s\n",buf);
		exit(1);
	}

	while( fgets(buf,120,in) != NULL )
	{
	   	mungeline(buf);
	}

	fclose(in);
	fclose(out);
}

void	option(char *str)
{
	unsigned long	sa, da;

	switch(str[1])
	{
		case 'o': /* output */
			if( sscanf(str+2,"%x=%x",&sa,&da) )
			{
				offset = da - sa;
				printf("changing block address 0x%08x to 0x%08x\n",sa,da);
			}
			else
			{
				fprintf(stderr,"bad format for -o: should be -o<srec-addr>=<mem-addr>\n");
				exit(1);
			}
			break;
		case 's': /* smunge */
			if (str[2] == 'w' )
			{
				do_swizzle16 = 0;
				do_swizzle32 = 1;
				do_swap = 0;
				printf("swizzle 32-bits, no swap\n");
			} else
			if (str[2] == 'W' )
			{
				do_swizzle16 = 0;
				do_swizzle32 = 1;
				do_swap = 1;
				printf("swizzle 32-bits, swap halfwords\n");
			} else
			if (str[2] == 'h' )
			{
				do_swizzle16 = 1;
				do_swizzle32 = 0;
				do_swap = 0;
				printf("swizzle 16-bits, no swap\n");
			} else
			if (str[2] == 'H' )
			{
				do_swizzle16 = 1;
				do_swizzle32 = 0;
				do_swap = 1;
				printf("swizzle 16-bits, swap halfwords\n");
			} else
				fprintf(stderr,"Unknown option - %s\n",str);
			break;
		default:
			fprintf(stderr,"Unknown option - %s\n",str);
	}
}

int	main(int argc, char **argv)
{
	while( -- argc )
	{
		++argv;
		if( **argv == '-' )
			option(*argv);
		else
			smunge(*argv);
	}
	return 0;
}