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/*
* Read in the 1st 52 4 byte words, and if over half
* match, write the majority value to stdout.
* This is intended to look at the ROMBOOT header for
* bootstrap that sets the NAND flash parameters
* for ATMEL's ROMBOOT to load bootstrap.
*/
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef DEBUG
#define DBGPRT(fmt,...) fprintf(stderr,fmt,##__VA_ARGS__)
#else
#define DBGPRT(fmt,...)
#endif
int
compare(const void *a, const void *b)
{
unsigned int a1 = *((const unsigned int *)a);
unsigned int b1 = *((const unsigned int *)b);
if(a1 < b1) return -1;
if(a1 > b1) return 1;
return 0;
}
#define NMEMB 52
int
main(int argc, char *argv)
{
unsigned int header[NMEMB];
int i,count;
int nmax, lastmax;
unsigned int previous, lastmaxval;
if(argc > 1) {
fprintf(stderr,
"Usage:\n"
" cat /dev/mtd1 | mts_hdr_copy >/tmp/hdr.bin\n"
" This comand reads standard input, and if over\n"
" half the 32 bit words for the first 52 words\n"
" are in agreement, 52 copies of the 32 bit word\n"
" are written to stdout. Otherwise we exit with\n"
" status 1. This command is intended to read the\n"
" existing bootstrap in /dev/mtd1, to create a\n"
" new bootstrap\n"
);
exit(0);
}
count = read(0,header,sizeof header);
if (count != sizeof header) {
DBGPRT("Could not read complete input\n");
exit(1);
}
qsort(header,NMEMB,sizeof(header[0]),compare);
for (i=0;i<NMEMB;i++)
DBGPRT("0x%8.8x\n",header[i]);
nmax = 0, lastmax = -1;
lastmaxval = 0;
previous = header[0]+1;
for (i=0;i<NMEMB;i++) {
DBGPRT("Considering 0x%x, previous 0x%x\n",header[i],previous);
if (previous == header[i]) {
nmax++;
DBGPRT("Matches, i=%d 0x%x, nmax=%d\n",i,header[i],nmax);
} else {
if (nmax > lastmax) {
lastmax = nmax;
DBGPRT("nmax > lastmax, lastmax %d\n",lastmax);
lastmaxval = previous;
}
previous = header[i];
nmax = 1;
}
}
if (nmax > lastmax) {
lastmax = nmax;
lastmaxval = previous;
}
DBGPRT("lastmax=%d\n",lastmax);
if (lastmax > NMEMB/2) {
for (i=0; i< NMEMB; i++)
header[i] = lastmaxval;
fprintf(stderr,"Attempting to write 52 copies of 0x%8.8x\n",lastmaxval);
if ((count = write(1,header,sizeof header)) == sizeof header)
exit(0);
else {
if(count >= 0)
fprintf(stderr,"ERROR: Wrote only %d of %llu bytes\n",count,(unsigned long long)(sizeof header));
else
perror("Error writing header");
}
}
fprintf(stderr,"ERROR: Found value 0x%x %d times out of 52 possible\n",lastmaxval,lastmax);
return 1;
}
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