-
Notifications
You must be signed in to change notification settings - Fork 11
/
checksumgen.c
44 lines (34 loc) · 994 Bytes
/
checksumgen.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
// Checksum generator for the Neopen bios
// Last mod: furrtek 22/10/2011
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[])
{
char ch;
FILE *romfile;
int short checksum=0; //16bits
int size;
if (argc != 2) {
puts("Usage: checksumgen flippedrom.bin\n");
} else {
romfile = fopen(argv[1],"r+b");
if (!romfile) {
write("Can't open %s\n",argv[1]);
return 1;
}
fseek(romfile,0,SEEK_SET);
for (size=0;size<0x80;size++) {
checksum += fgetc(romfile);
}
fseek(romfile,0x82,SEEK_SET);
for (size=0;size<0x20000-0x82;size++) {
checksum += fgetc(romfile);
}
printf("Checksum: %X\n",checksum & 0xFFFF);
fseek(romfile,0x80,SEEK_SET);
fwrite(&checksum,sizeof(int short),1,romfile);
fclose(romfile);
}
return 0;
}