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 * Adapted for 64 bit little endian images by Andrew Tauferner. 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * Usage: addnote zImage 17 */ 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <fcntl.h> 21 #include <unistd.h> 22 #include <string.h> 23 24 /* CHRP note section */ 25 static const char arch[] = "PowerPC"; 26 27 #define N_DESCR 6 28 unsigned int descr[N_DESCR] = { 29 0xffffffff, /* real-mode = true */ 30 0x02000000, /* real-base, i.e. where we expect OF to be */ 31 0xffffffff, /* real-size */ 32 0xffffffff, /* virt-base */ 33 0xffffffff, /* virt-size */ 34 0x4000, /* load-base */ 35 }; 36 37 /* RPA note section */ 38 static const char rpaname[] = "IBM,RPA-Client-Config"; 39 40 /* 41 * Note: setting ignore_my_client_config *should* mean that OF ignores 42 * all the other fields, but there is a firmware bug which means that 43 * it looks at the splpar field at least. So these values need to be 44 * reasonable. 45 */ 46 #define N_RPA_DESCR 8 47 unsigned int rpanote[N_RPA_DESCR] = { 48 0, /* lparaffinity */ 49 64, /* min_rmo_size */ 50 0, /* min_rmo_percent */ 51 40, /* max_pft_size */ 52 1, /* splpar */ 53 -1, /* min_load */ 54 0, /* new_mem_def */ 55 1, /* ignore_my_client_config */ 56 }; 57 58 #define ROUNDUP(len) (((len) + 3) & ~3) 59 60 unsigned char buf[1024]; 61 #define ELFDATA2LSB 1 62 #define ELFDATA2MSB 2 63 static int e_data = ELFDATA2MSB; 64 #define ELFCLASS32 1 65 #define ELFCLASS64 2 66 static int e_class = ELFCLASS32; 67 68 #define GET_16BE(off) ((buf[off] << 8) + (buf[(off)+1])) 69 #define GET_32BE(off) ((GET_16BE(off) << 16U) + GET_16BE((off)+2U)) 70 #define GET_64BE(off) ((((unsigned long long)GET_32BE(off)) << 32ULL) + \ 71 ((unsigned long long)GET_32BE((off)+4ULL))) 72 #define PUT_16BE(off, v)(buf[off] = ((v) >> 8) & 0xff, \ 73 buf[(off) + 1] = (v) & 0xff) 74 #define PUT_32BE(off, v)(PUT_16BE((off), (v) >> 16L), PUT_16BE((off) + 2, (v))) 75 #define PUT_64BE(off, v)((PUT_32BE((off), (v) >> 32L), \ 76 PUT_32BE((off) + 4, (v)))) 77 78 #define GET_16LE(off) ((buf[off]) + (buf[(off)+1] << 8)) 79 #define GET_32LE(off) (GET_16LE(off) + (GET_16LE((off)+2U) << 16U)) 80 #define GET_64LE(off) ((unsigned long long)GET_32LE(off) + \ 81 (((unsigned long long)GET_32LE((off)+4ULL)) << 32ULL)) 82 #define PUT_16LE(off, v) (buf[off] = (v) & 0xff, \ 83 buf[(off) + 1] = ((v) >> 8) & 0xff) 84 #define PUT_32LE(off, v) (PUT_16LE((off), (v)), PUT_16LE((off) + 2, (v) >> 16L)) 85 #define PUT_64LE(off, v) (PUT_32LE((off), (v)), PUT_32LE((off) + 4, (v) >> 32L)) 86 87 #define GET_16(off) (e_data == ELFDATA2MSB ? GET_16BE(off) : GET_16LE(off)) 88 #define GET_32(off) (e_data == ELFDATA2MSB ? GET_32BE(off) : GET_32LE(off)) 89 #define GET_64(off) (e_data == ELFDATA2MSB ? GET_64BE(off) : GET_64LE(off)) 90 #define PUT_16(off, v) (e_data == ELFDATA2MSB ? PUT_16BE(off, v) : \ 91 PUT_16LE(off, v)) 92 #define PUT_32(off, v) (e_data == ELFDATA2MSB ? PUT_32BE(off, v) : \ 93 PUT_32LE(off, v)) 94 #define PUT_64(off, v) (e_data == ELFDATA2MSB ? PUT_64BE(off, v) : \ 95 PUT_64LE(off, v)) 96 97 /* Structure of an ELF file */ 98 #define E_IDENT 0 /* ELF header */ 99 #define E_PHOFF (e_class == ELFCLASS32 ? 28 : 32) 100 #define E_PHENTSIZE (e_class == ELFCLASS32 ? 42 : 54) 101 #define E_PHNUM (e_class == ELFCLASS32 ? 44 : 56) 102 #define E_HSIZE (e_class == ELFCLASS32 ? 52 : 64) 103 104 #define EI_MAGIC 0 /* offsets in E_IDENT area */ 105 #define EI_CLASS 4 106 #define EI_DATA 5 107 108 #define PH_TYPE 0 /* ELF program header */ 109 #define PH_OFFSET (e_class == ELFCLASS32 ? 4 : 8) 110 #define PH_FILESZ (e_class == ELFCLASS32 ? 16 : 32) 111 #define PH_HSIZE (e_class == ELFCLASS32 ? 32 : 56) 112 113 #define PT_NOTE 4 /* Program header type = note */ 114 115 116 unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' }; 117 118 int 119 main(int ac, char **av) 120 { 121 int fd, n, i; 122 unsigned long ph, ps, np; 123 long nnote, nnote2, ns; 124 125 if (ac != 2) { 126 fprintf(stderr, "Usage: %s elf-file\n", av[0]); 127 exit(1); 128 } 129 fd = open(av[1], O_RDWR); 130 if (fd < 0) { 131 perror(av[1]); 132 exit(1); 133 } 134 135 nnote = 12 + ROUNDUP(strlen(arch) + 1) + sizeof(descr); 136 nnote2 = 12 + ROUNDUP(strlen(rpaname) + 1) + sizeof(rpanote); 137 138 n = read(fd, buf, sizeof(buf)); 139 if (n < 0) { 140 perror("read"); 141 exit(1); 142 } 143 144 if (memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0) 145 goto notelf; 146 e_class = buf[E_IDENT+EI_CLASS]; 147 if (e_class != ELFCLASS32 && e_class != ELFCLASS64) 148 goto notelf; 149 e_data = buf[E_IDENT+EI_DATA]; 150 if (e_data != ELFDATA2MSB && e_data != ELFDATA2LSB) 151 goto notelf; 152 if (n < E_HSIZE) 153 goto notelf; 154 155 ph = (e_class == ELFCLASS32 ? GET_32(E_PHOFF) : GET_64(E_PHOFF)); 156 ps = GET_16(E_PHENTSIZE); 157 np = GET_16(E_PHNUM); 158 if (ph < E_HSIZE || ps < PH_HSIZE || np < 1) 159 goto notelf; 160 if (ph + (np + 2) * ps + nnote + nnote2 > n) 161 goto nospace; 162 163 for (i = 0; i < np; ++i) { 164 if (GET_32(ph + PH_TYPE) == PT_NOTE) { 165 fprintf(stderr, "%s already has a note entry\n", 166 av[1]); 167 exit(0); 168 } 169 ph += ps; 170 } 171 172 /* XXX check that the area we want to use is all zeroes */ 173 for (i = 0; i < 2 * ps + nnote + nnote2; ++i) 174 if (buf[ph + i] != 0) 175 goto nospace; 176 177 /* fill in the program header entry */ 178 ns = ph + 2 * ps; 179 PUT_32(ph + PH_TYPE, PT_NOTE); 180 if (e_class == ELFCLASS32) 181 PUT_32(ph + PH_OFFSET, ns); 182 else 183 PUT_64(ph + PH_OFFSET, ns); 184 185 if (e_class == ELFCLASS32) 186 PUT_32(ph + PH_FILESZ, nnote); 187 else 188 PUT_64(ph + PH_FILESZ, nnote); 189 190 /* fill in the note area we point to */ 191 /* XXX we should probably make this a proper section */ 192 PUT_32(ns, strlen(arch) + 1); 193 PUT_32(ns + 4, N_DESCR * 4); 194 PUT_32(ns + 8, 0x1275); 195 strcpy((char *) &buf[ns + 12], arch); 196 ns += 12 + strlen(arch) + 1; 197 for (i = 0; i < N_DESCR; ++i, ns += 4) 198 PUT_32BE(ns, descr[i]); 199 200 /* fill in the second program header entry and the RPA note area */ 201 ph += ps; 202 PUT_32(ph + PH_TYPE, PT_NOTE); 203 if (e_class == ELFCLASS32) 204 PUT_32(ph + PH_OFFSET, ns); 205 else 206 PUT_64(ph + PH_OFFSET, ns); 207 208 if (e_class == ELFCLASS32) 209 PUT_32(ph + PH_FILESZ, nnote); 210 else 211 PUT_64(ph + PH_FILESZ, nnote2); 212 213 /* fill in the note area we point to */ 214 PUT_32(ns, strlen(rpaname) + 1); 215 PUT_32(ns + 4, sizeof(rpanote)); 216 PUT_32(ns + 8, 0x12759999); 217 strcpy((char *) &buf[ns + 12], rpaname); 218 ns += 12 + ROUNDUP(strlen(rpaname) + 1); 219 for (i = 0; i < N_RPA_DESCR; ++i, ns += 4) 220 PUT_32BE(ns, rpanote[i]); 221 222 /* Update the number of program headers */ 223 PUT_16(E_PHNUM, np + 2); 224 225 /* write back */ 226 i = lseek(fd, (long) 0, SEEK_SET); 227 if (i < 0) { 228 perror("lseek"); 229 exit(1); 230 } 231 i = write(fd, buf, n); 232 if (i < 0) { 233 perror("write"); 234 exit(1); 235 } 236 if (i < n) { 237 fprintf(stderr, "%s: write truncated\n", av[1]); 238 exit(1); 239 } 240 241 exit(0); 242 243 notelf: 244 fprintf(stderr, "%s does not appear to be an ELF file\n", av[1]); 245 exit(1); 246 247 nospace: 248 fprintf(stderr, "sorry, I can't find space in %s to put the note\n", 249 av[1]); 250 exit(1); 251 } 252