1#include <stdio.h>
2#include <sys/types.h>
3#include <sys/stat.h>
4#include <unistd.h>
5#include <string.h>
6#include <stdlib.h>
7
8int main(int argc, char **argv){
9	unsigned char *buffer = malloc(64 * 1024);
10	struct stat s;
11	unsigned int size_vmlinux = 0, real_size_vmlinux = 0;
12	const unsigned char *magic_str = "ACME_PART_MAGIC";
13	unsigned int loop;
14	unsigned char *magic;
15
16	if(argc != 3){
17		printf("%s in out\n", argv[0]);
18		return 1;
19	}
20
21	printf("Generating image\n");
22
23	FILE *vmlinux = fopen(argv[1], "r");
24	FILE *vmlinux_out = fopen(argv[2], "w");
25	if((!vmlinux) || (!vmlinux_out)){
26		printf("Error opening a file\n");
27		return 1;
28	}
29
30	stat(argv[1], &s);
31	size_vmlinux = s.st_size;
32	real_size_vmlinux = (size_vmlinux & 0xffff0000) + 0x10000;
33
34	printf("vmlinux = 0x%.08X / 0x%.08X\n", size_vmlinux, real_size_vmlinux);
35
36	unsigned int t = fread(buffer, 1, 64 * 1024, vmlinux);
37	for(loop = 0; loop < (64 * 1024) - sizeof(magic_str); loop++){
38		if(buffer[loop] == magic_str[0]){
39			if((magic = strstr(&buffer[loop], magic_str))){
40				printf("Magic at 0x%.08X %p %p\n", magic - buffer, magic, buffer);
41				printf("Found Magic %X%X%X%X\n",
42					buffer[loop + strlen(magic_str)],
43					buffer[loop + strlen(magic_str) + 2],
44					buffer[loop + strlen(magic_str) + 1],
45					buffer[loop + strlen(magic_str) + 3]);
46
47				buffer[loop + strlen(magic_str)] = real_size_vmlinux >> 24;
48				buffer[loop + strlen(magic_str) + 2] = (real_size_vmlinux >> 16) & 0xff;
49				buffer[loop + strlen(magic_str) + 1] = (real_size_vmlinux >> 8) & 0xff;
50				buffer[loop + strlen(magic_str) + 3] = (real_size_vmlinux) & 0xff;
51
52				printf("Replaced with %.02X%.02X%.02X%.02X\n",
53					buffer[loop + strlen(magic_str)],
54					buffer[loop + strlen(magic_str) + 2],
55					buffer[loop + strlen(magic_str) + 1],
56					buffer[loop + strlen(magic_str) + 3]);
57
58			}
59		}
60	}
61
62	fwrite(buffer, 1, 64 * 1024, vmlinux_out);
63	real_size_vmlinux -= 64 * 1024;
64	do {
65		real_size_vmlinux -= 64 * 1024;
66		memset(buffer, 0, 64 * 1024);
67		fread(buffer, 1, 64 * 1024, vmlinux);
68		fwrite(buffer, 1, 64 * 1024, vmlinux_out);
69	} while (real_size_vmlinux);
70
71	return 0;
72}
73