1 /*
2  * Copyright (C) 2011 Samsung Electronics
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <unistd.h>
10 #include <fcntl.h>
11 #include <errno.h>
12 #include <string.h>
13 #include <sys/stat.h>
14 
15 #define BUFSIZE			(16*1024)
16 #define IMG_SIZE		(16*1024)
17 #define SPL_HEADER_SIZE		16
18 #define FILE_PERM		(S_IRUSR | S_IWUSR | S_IRGRP \
19 				| S_IWGRP | S_IROTH | S_IWOTH)
20 #define SPL_HEADER		"S5PC210 HEADER  "
21 /*
22 * Requirement:
23 * IROM code reads first 14K bytes from boot device.
24 * It then calculates the checksum of 14K-4 bytes and compare with data at
25 * 14K-4 offset.
26 *
27 * This function takes two filenames:
28 * IN  "u-boot-spl.bin" and
29 * OUT "$(BOARD)-spl.bin as filenames.
30 * It reads the "u-boot-spl.bin" in 16K buffer.
31 * It calculates checksum of 14K-4 Bytes and stores at 14K-4 offset in buffer.
32 * It writes the buffer to "$(BOARD)-spl.bin" file.
33 */
34 
35 int main(int argc, char **argv)
36 {
37 	int i, len;
38 	unsigned char buffer[BUFSIZE] = {0};
39 	int ifd, ofd;
40 	unsigned int checksum = 0, count;
41 
42 	if (argc != 3) {
43 		printf(" %d Wrong number of arguments\n", argc);
44 		exit(EXIT_FAILURE);
45 	}
46 
47 	ifd = open(argv[1], O_RDONLY);
48 	if (ifd < 0) {
49 		fprintf(stderr, "%s: Can't open %s: %s\n",
50 			argv[0], argv[1], strerror(errno));
51 		exit(EXIT_FAILURE);
52 	}
53 
54 	ofd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, FILE_PERM);
55 	if (ofd < 0) {
56 		fprintf(stderr, "%s: Can't open %s: %s\n",
57 			argv[0], argv[2], strerror(errno));
58 		if (ifd)
59 			close(ifd);
60 		exit(EXIT_FAILURE);
61 	}
62 
63 	len = lseek(ifd, 0, SEEK_END);
64 	lseek(ifd, 0, SEEK_SET);
65 
66 	memcpy(&buffer[0], SPL_HEADER, SPL_HEADER_SIZE);
67 
68 	count = (len < (IMG_SIZE - SPL_HEADER_SIZE))
69 		? len : (IMG_SIZE - SPL_HEADER_SIZE);
70 
71 	if (read(ifd, buffer + SPL_HEADER_SIZE, count) != count) {
72 		fprintf(stderr, "%s: Can't read %s: %s\n",
73 			argv[0], argv[1], strerror(errno));
74 
75 		if (ifd)
76 			close(ifd);
77 		if (ofd)
78 			close(ofd);
79 
80 		exit(EXIT_FAILURE);
81 	}
82 
83 	for (i = 0; i < IMG_SIZE - SPL_HEADER_SIZE; i++)
84 		checksum += buffer[i+16];
85 
86 	*(unsigned long *)buffer ^= 0x1f;
87 	*(unsigned long *)(buffer+4) ^= checksum;
88 
89 	for (i = 1; i < SPL_HEADER_SIZE; i++)
90 		buffer[i] ^= buffer[i-1];
91 
92 	if (write(ofd, buffer, BUFSIZE) != BUFSIZE) {
93 		fprintf(stderr, "%s: Can't write %s: %s\n",
94 			argv[0], argv[2], strerror(errno));
95 
96 		if (ifd)
97 			close(ifd);
98 		if (ofd)
99 			close(ofd);
100 
101 		exit(EXIT_FAILURE);
102 	}
103 
104 	if (ifd)
105 		close(ifd);
106 	if (ofd)
107 		close(ofd);
108 
109 	return EXIT_SUCCESS;
110 }
111