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1da177e4 LT |
1 | /* |
2 | * Program to hack in a PT_NOTE program header entry in an ELF file. | |
3 | * This is needed for OF on RS/6000s to load an image correctly. | |
4 | * Note that OF needs a program header entry for the note, not an | |
5 | * ELF section. | |
6 | * | |
7 | * Copyright 2000 Paul Mackerras. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | * | |
14 | * Usage: addnote zImage | |
15 | */ | |
16 | #include <stdio.h> | |
17 | #include <stdlib.h> | |
18 | #include <fcntl.h> | |
19 | #include <unistd.h> | |
20 | #include <string.h> | |
21 | ||
66faf984 | 22 | /* CHRP note section */ |
1da177e4 LT |
23 | char arch[] = "PowerPC"; |
24 | ||
25 | #define N_DESCR 6 | |
26 | unsigned int descr[N_DESCR] = { | |
27 | 0xffffffff, /* real-mode = true */ | |
28 | 0x00c00000, /* real-base, i.e. where we expect OF to be */ | |
29 | 0xffffffff, /* real-size */ | |
30 | 0xffffffff, /* virt-base */ | |
31 | 0xffffffff, /* virt-size */ | |
32 | 0x4000, /* load-base */ | |
33 | }; | |
34 | ||
66faf984 PM |
35 | /* RPA note section */ |
36 | char rpaname[] = "IBM,RPA-Client-Config"; | |
37 | ||
38 | /* | |
39 | * Note: setting ignore_my_client_config *should* mean that OF ignores | |
40 | * all the other fields, but there is a firmware bug which means that | |
41 | * it looks at the splpar field at least. So these values need to be | |
42 | * reasonable. | |
43 | */ | |
44 | #define N_RPA_DESCR 8 | |
45 | unsigned int rpanote[N_RPA_DESCR] = { | |
46 | 0, /* lparaffinity */ | |
47 | 64, /* min_rmo_size */ | |
48 | 0, /* min_rmo_percent */ | |
49 | 40, /* max_pft_size */ | |
50 | 1, /* splpar */ | |
51 | -1, /* min_load */ | |
52 | 0, /* new_mem_def */ | |
53 | 1, /* ignore_my_client_config */ | |
54 | }; | |
55 | ||
56 | #define ROUNDUP(len) (((len) + 3) & ~3) | |
57 | ||
1da177e4 LT |
58 | unsigned char buf[512]; |
59 | ||
60 | #define GET_16BE(off) ((buf[off] << 8) + (buf[(off)+1])) | |
61 | #define GET_32BE(off) ((GET_16BE(off) << 16) + GET_16BE((off)+2)) | |
62 | ||
63 | #define PUT_16BE(off, v) (buf[off] = ((v) >> 8) & 0xff, \ | |
64 | buf[(off) + 1] = (v) & 0xff) | |
65 | #define PUT_32BE(off, v) (PUT_16BE((off), (v) >> 16), \ | |
66 | PUT_16BE((off) + 2, (v))) | |
67 | ||
68 | /* Structure of an ELF file */ | |
69 | #define E_IDENT 0 /* ELF header */ | |
70 | #define E_PHOFF 28 | |
71 | #define E_PHENTSIZE 42 | |
72 | #define E_PHNUM 44 | |
73 | #define E_HSIZE 52 /* size of ELF header */ | |
74 | ||
75 | #define EI_MAGIC 0 /* offsets in E_IDENT area */ | |
76 | #define EI_CLASS 4 | |
77 | #define EI_DATA 5 | |
78 | ||
79 | #define PH_TYPE 0 /* ELF program header */ | |
80 | #define PH_OFFSET 4 | |
81 | #define PH_FILESZ 16 | |
82 | #define PH_HSIZE 32 /* size of program header */ | |
83 | ||
84 | #define PT_NOTE 4 /* Program header type = note */ | |
85 | ||
86 | #define ELFCLASS32 1 | |
87 | #define ELFDATA2MSB 2 | |
88 | ||
89 | unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' }; | |
90 | ||
91 | int | |
92 | main(int ac, char **av) | |
93 | { | |
94 | int fd, n, i; | |
95 | int ph, ps, np; | |
66faf984 | 96 | int nnote, nnote2, ns; |
1da177e4 LT |
97 | |
98 | if (ac != 2) { | |
99 | fprintf(stderr, "Usage: %s elf-file\n", av[0]); | |
100 | exit(1); | |
101 | } | |
102 | fd = open(av[1], O_RDWR); | |
103 | if (fd < 0) { | |
104 | perror(av[1]); | |
105 | exit(1); | |
106 | } | |
107 | ||
66faf984 PM |
108 | nnote = 12 + ROUNDUP(strlen(arch) + 1) + sizeof(descr); |
109 | nnote2 = 12 + ROUNDUP(strlen(rpaname) + 1) + sizeof(rpanote); | |
1da177e4 LT |
110 | |
111 | n = read(fd, buf, sizeof(buf)); | |
112 | if (n < 0) { | |
113 | perror("read"); | |
114 | exit(1); | |
115 | } | |
116 | ||
117 | if (n < E_HSIZE || memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0) | |
118 | goto notelf; | |
119 | ||
120 | if (buf[E_IDENT+EI_CLASS] != ELFCLASS32 | |
121 | || buf[E_IDENT+EI_DATA] != ELFDATA2MSB) { | |
122 | fprintf(stderr, "%s is not a big-endian 32-bit ELF image\n", | |
123 | av[1]); | |
124 | exit(1); | |
125 | } | |
126 | ||
127 | ph = GET_32BE(E_PHOFF); | |
128 | ps = GET_16BE(E_PHENTSIZE); | |
129 | np = GET_16BE(E_PHNUM); | |
130 | if (ph < E_HSIZE || ps < PH_HSIZE || np < 1) | |
131 | goto notelf; | |
66faf984 | 132 | if (ph + (np + 2) * ps + nnote + nnote2 > n) |
1da177e4 LT |
133 | goto nospace; |
134 | ||
135 | for (i = 0; i < np; ++i) { | |
136 | if (GET_32BE(ph + PH_TYPE) == PT_NOTE) { | |
137 | fprintf(stderr, "%s already has a note entry\n", | |
138 | av[1]); | |
139 | exit(0); | |
140 | } | |
141 | ph += ps; | |
142 | } | |
143 | ||
144 | /* XXX check that the area we want to use is all zeroes */ | |
66faf984 | 145 | for (i = 0; i < 2 * ps + nnote + nnote2; ++i) |
1da177e4 LT |
146 | if (buf[ph + i] != 0) |
147 | goto nospace; | |
148 | ||
149 | /* fill in the program header entry */ | |
66faf984 | 150 | ns = ph + 2 * ps; |
1da177e4 LT |
151 | PUT_32BE(ph + PH_TYPE, PT_NOTE); |
152 | PUT_32BE(ph + PH_OFFSET, ns); | |
153 | PUT_32BE(ph + PH_FILESZ, nnote); | |
154 | ||
155 | /* fill in the note area we point to */ | |
156 | /* XXX we should probably make this a proper section */ | |
157 | PUT_32BE(ns, strlen(arch) + 1); | |
158 | PUT_32BE(ns + 4, N_DESCR * 4); | |
159 | PUT_32BE(ns + 8, 0x1275); | |
decd300b | 160 | strcpy((char *) &buf[ns + 12], arch); |
1da177e4 | 161 | ns += 12 + strlen(arch) + 1; |
66faf984 PM |
162 | for (i = 0; i < N_DESCR; ++i, ns += 4) |
163 | PUT_32BE(ns, descr[i]); | |
164 | ||
165 | /* fill in the second program header entry and the RPA note area */ | |
166 | ph += ps; | |
167 | PUT_32BE(ph + PH_TYPE, PT_NOTE); | |
168 | PUT_32BE(ph + PH_OFFSET, ns); | |
169 | PUT_32BE(ph + PH_FILESZ, nnote2); | |
170 | ||
171 | /* fill in the note area we point to */ | |
172 | PUT_32BE(ns, strlen(rpaname) + 1); | |
173 | PUT_32BE(ns + 4, sizeof(rpanote)); | |
174 | PUT_32BE(ns + 8, 0x12759999); | |
decd300b | 175 | strcpy((char *) &buf[ns + 12], rpaname); |
66faf984 PM |
176 | ns += 12 + ROUNDUP(strlen(rpaname) + 1); |
177 | for (i = 0; i < N_RPA_DESCR; ++i, ns += 4) | |
178 | PUT_32BE(ns, rpanote[i]); | |
1da177e4 LT |
179 | |
180 | /* Update the number of program headers */ | |
66faf984 | 181 | PUT_16BE(E_PHNUM, np + 2); |
1da177e4 LT |
182 | |
183 | /* write back */ | |
184 | lseek(fd, (long) 0, SEEK_SET); | |
185 | i = write(fd, buf, n); | |
186 | if (i < 0) { | |
187 | perror("write"); | |
188 | exit(1); | |
189 | } | |
190 | if (i < n) { | |
191 | fprintf(stderr, "%s: write truncated\n", av[1]); | |
192 | exit(1); | |
193 | } | |
194 | ||
195 | exit(0); | |
196 | ||
197 | notelf: | |
66faf984 | 198 | fprintf(stderr, "%s does not appear to be an ELF file\n", av[1]); |
1da177e4 LT |
199 | exit(1); |
200 | ||
201 | nospace: | |
202 | fprintf(stderr, "sorry, I can't find space in %s to put the note\n", | |
66faf984 | 203 | av[1]); |
1da177e4 LT |
204 | exit(1); |
205 | } |