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

#define BUFFERSIZE		0xe0000
#define CHECKSUMSIZE	8
#define MAXFLASH		(BUFFERSIZE - strlen(Signature) - CHECKSUMSIZE)
#define SIGOFFSET		MAXFLASH
#define CHECKSUMSIG		0xaabbbbaa

#define INFILE			"NML.ARJ"

const char Signature[] = {
	"WGRT-4T0        T1.0 -01"
};

unsigned int Checksum(unsigned int *pBuffer, int nLength)
{
	unsigned int nChecksum = 0;
	int nIndex;

	for(nIndex=0; nIndex<nLength; nIndex++)
		nChecksum = nChecksum ^ pBuffer[nIndex];

	nChecksum = nChecksum ^ CHECKSUMSIG;

	return(nChecksum);
}

int main(int argc, char *argv[])
{
	FILE *pInFile;
	FILE *pOutFile;
	unsigned int *pBuffer;
	int nCount;
	unsigned int nChecksum;
	
	if(argc < 2) {
		printf("Usage:%s outfile\n", argv[0]);
		exit(0);
	}

	if((pInFile = fopen(INFILE, "rb")) != NULL) {
		if((pOutFile = fopen(argv[1], "wb")) != NULL) {
			if((pBuffer = (unsigned int *)calloc(BUFFERSIZE, 1)) != NULL) {
				nCount = fread(pBuffer, 1, MAXFLASH, pInFile);
				printf("Read %ld bytes\n", nCount);

				memcpy(((unsigned char *)pBuffer + SIGOFFSET), (void *)Signature, strlen(Signature));
				nChecksum = Checksum(pBuffer, (BUFFERSIZE-CHECKSUMSIZE)/sizeof(unsigned int));
				printf("Checksum:%08x\n", nChecksum);

				pBuffer[(BUFFERSIZE-sizeof(unsigned int))/sizeof(unsigned int)] = nChecksum;

				nCount = fwrite(pBuffer, 1, BUFFERSIZE, pOutFile);
				printf("Wrote %ld bytes\n", nCount);
			}
			else
				printf("Error allocating buffer !\n");
			
			fclose(pOutFile);
		}
		else
			printf("Error opening output file:%s !\n", argv[1]);

		fclose(pInFile);
	}
	else
		printf("Error opening input file:%s !\n", INFILE);

	return(0);
}