1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Makes a tree bootable image for IBM Evaluation boards. |
4 | * Basically, just take a zImage, skip the ELF header, and stuff |
5 | * a 32 byte header on the front. |
6 | * |
7 | * We use htonl, which is a network macro, to make sure we're doing |
8 | * The Right Thing on an LE machine. It's non-obvious, but it should |
9 | * work on anything BSD'ish. |
10 | */ |
11 | |
12 | #include <fcntl.h> |
13 | #include <stdio.h> |
14 | #include <stdlib.h> |
15 | #include <string.h> |
16 | #include <sys/stat.h> |
17 | #include <unistd.h> |
18 | #include <netinet/in.h> |
19 | #ifdef __sun__ |
20 | #include <inttypes.h> |
21 | #else |
22 | #include <stdint.h> |
23 | #endif |
24 | |
25 | /* This gets tacked on the front of the image. There are also a few |
26 | * bytes allocated after the _start label used by the boot rom (see |
27 | * head.S for details). |
28 | */ |
29 | typedef struct boot_block { |
30 | uint32_t bb_magic; /* 0x0052504F */ |
31 | uint32_t bb_dest; /* Target address of the image */ |
32 | uint32_t bb_num_512blocks; /* Size, rounded-up, in 512 byte blks */ |
33 | uint32_t bb_debug_flag; /* Run debugger or image after load */ |
34 | uint32_t bb_entry_point; /* The image address to start */ |
35 | uint32_t bb_checksum; /* 32 bit checksum including header */ |
36 | uint32_t reserved[2]; |
37 | } boot_block_t; |
38 | |
39 | #define IMGBLK 512 |
40 | unsigned int tmpbuf[IMGBLK / sizeof(unsigned int)]; |
41 | |
42 | int main(int argc, char *argv[]) |
43 | { |
44 | int in_fd, out_fd; |
45 | int nblks, i; |
46 | unsigned int cksum, *cp; |
47 | struct stat st; |
48 | boot_block_t bt; |
49 | |
50 | if (argc < 5) { |
51 | fprintf(stderr, "usage: %s <zImage-file> <boot-image> <load address> <entry point>\n" ,argv[0]); |
52 | exit(1); |
53 | } |
54 | |
55 | if (stat(argv[1], &st) < 0) { |
56 | perror("stat" ); |
57 | exit(2); |
58 | } |
59 | |
60 | nblks = (st.st_size + IMGBLK) / IMGBLK; |
61 | |
62 | bt.bb_magic = htonl(0x0052504F); |
63 | |
64 | /* If we have the optional entry point parameter, use it */ |
65 | bt.bb_dest = htonl(strtoul(argv[3], NULL, 0)); |
66 | bt.bb_entry_point = htonl(strtoul(argv[4], NULL, 0)); |
67 | |
68 | /* We know these from the linker command. |
69 | * ...and then move it up into memory a little more so the |
70 | * relocation can happen. |
71 | */ |
72 | bt.bb_num_512blocks = htonl(nblks); |
73 | bt.bb_debug_flag = 0; |
74 | |
75 | bt.bb_checksum = 0; |
76 | |
77 | /* To be neat and tidy :-). |
78 | */ |
79 | bt.reserved[0] = 0; |
80 | bt.reserved[1] = 0; |
81 | |
82 | if ((in_fd = open(argv[1], O_RDONLY)) < 0) { |
83 | perror("zImage open" ); |
84 | exit(3); |
85 | } |
86 | |
87 | if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) { |
88 | perror("bootfile open" ); |
89 | exit(3); |
90 | } |
91 | |
92 | cksum = 0; |
93 | cp = (void *)&bt; |
94 | for (i = 0; i < sizeof(bt) / sizeof(unsigned int); i++) |
95 | cksum += *cp++; |
96 | |
97 | /* Assume zImage is an ELF file, and skip the 64K header. |
98 | */ |
99 | if (read(in_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) { |
100 | fprintf(stderr, "%s is too small to be an ELF image\n" , |
101 | argv[1]); |
102 | exit(4); |
103 | } |
104 | |
105 | if (tmpbuf[0] != htonl(0x7f454c46)) { |
106 | fprintf(stderr, "%s is not an ELF image\n" , argv[1]); |
107 | exit(4); |
108 | } |
109 | |
110 | if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) { |
111 | fprintf(stderr, "%s failed to seek in ELF image\n" , argv[1]); |
112 | exit(4); |
113 | } |
114 | |
115 | nblks -= (64 * 1024) / IMGBLK; |
116 | |
117 | /* And away we go...... |
118 | */ |
119 | if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) { |
120 | perror("boot-image write" ); |
121 | exit(5); |
122 | } |
123 | |
124 | while (nblks-- > 0) { |
125 | if (read(in_fd, tmpbuf, sizeof(tmpbuf)) < 0) { |
126 | perror("zImage read" ); |
127 | exit(5); |
128 | } |
129 | cp = tmpbuf; |
130 | for (i = 0; i < sizeof(tmpbuf) / sizeof(unsigned int); i++) |
131 | cksum += *cp++; |
132 | if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) { |
133 | perror("boot-image write" ); |
134 | exit(5); |
135 | } |
136 | } |
137 | |
138 | /* rewrite the header with the computed checksum. |
139 | */ |
140 | bt.bb_checksum = htonl(cksum); |
141 | if (lseek(out_fd, 0, SEEK_SET) < 0) { |
142 | perror("rewrite seek" ); |
143 | exit(1); |
144 | } |
145 | if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) { |
146 | perror("boot-image rewrite" ); |
147 | exit(1); |
148 | } |
149 | |
150 | exit(0); |
151 | } |
152 | |