mirror of
https://github.com/cc65/cc65.git
synced 2024-12-29 13:31:59 +00:00
36 lines
701 B
C
36 lines
701 B
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
|
|
FILE *in;
|
|
unsigned int n, i, c;
|
|
|
|
void usage(char *arg)
|
|
{
|
|
printf("usage: %s file\n", arg);
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
if (argc < 2) {
|
|
usage(argv[0]);
|
|
exit(-1);
|
|
}
|
|
|
|
if (!(in = fopen(argv[1], "r+b"))) {
|
|
fprintf(stderr, "couldnt open: '%s'\n", argv[1]);
|
|
exit(-1);
|
|
}
|
|
/* read 0x1000 bytes from 0x7000-0x7fff (offset 0x1000) */
|
|
fseek(in, 0x1000, SEEK_SET);
|
|
n = 0; for (i = 0; i < 0x1000; i++) {
|
|
c = fgetc(in);
|
|
n += c;
|
|
}
|
|
/* write checksum to header */
|
|
fseek(in, 0, SEEK_SET);
|
|
fputc(n & 0xff, in);
|
|
fputc((n >> 8) & 0xff, in);
|
|
|
|
fclose(in);
|
|
return 0;
|
|
}
|