65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
|
/*
|
||
|
|
* Copyright 2010 Google Inc.
|
||
|
|
*
|
||
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
* you may not use this file except in compliance with the License.
|
||
|
|
* You may obtain a copy of the License at
|
||
|
|
*
|
||
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
*
|
||
|
|
* Unless required by applicable law or agreed to in writing, software
|
||
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
* See the License for the specific language governing permissions and
|
||
|
|
* limitations under the License.
|
||
|
|
*
|
||
|
|
* compute rom checksum byte
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <sys/types.h>
|
||
|
|
|
||
|
|
#define MAX_SIZE 65536
|
||
|
|
unsigned char buf[MAX_SIZE];
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
ssize_t fsize;
|
||
|
|
int i, sum, fd;
|
||
|
|
unsigned char csum;
|
||
|
|
|
||
|
|
if (argc < 2) {
|
||
|
|
fprintf(stderr, "usage: %s filename\n", argv[0]);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
if ((fd = open(argv[1], O_RDWR)) < 0) {
|
||
|
|
perror(argv[1]);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
if ((fsize = read(fd, buf, MAX_SIZE)) < 0) {
|
||
|
|
perror(argv[1]);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
if (fsize >= MAX_SIZE && read(fd, &buf[MAX_SIZE - 1], 1) > 0) {
|
||
|
|
fprintf(stderr, "FAIL: %s is larger than %d bytes\n", argv[1], MAX_SIZE);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
i = fsize - 2048 * (fsize / 2048);
|
||
|
|
if (i != 2047) {
|
||
|
|
fprintf(stderr, "FAIL: %s is %zd bytes, need 2K pad-1\n", argv[1], fsize);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
for (i = sum = 0; i < fsize; i++) {
|
||
|
|
sum += buf[i];
|
||
|
|
}
|
||
|
|
sum &= 0xff;
|
||
|
|
csum = -sum & 0xff;
|
||
|
|
write(fd, &csum, 1);
|
||
|
|
close(fd);
|
||
|
|
fprintf(stderr, "%s: sum = 0x%02x, wrote byte 0x%02x\n", argv[1], sum, csum);
|
||
|
|
return 0;
|
||
|
|
}
|