LXR linux/arch/powerpc/boot/addnote.c

   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 */
  25static const char arch[] = "PowerPC";
  26
  27#define N_DESCR 6
  28unsigned 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 */
  38static 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
  47unsigned 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
  60unsigned char buf[1024];
  61#define ELFDATA2LSB     1
  62#define ELFDATA2MSB     2
  63static int e_data = ELFDATA2MSB;
  64#define ELFCLASS32      1
  65#define ELFCLASS64      2
  66static 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
 116unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' };
 117
 118int
 119main(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        lseek(fd, (long) 0, SEEK_SET);
 227        i = write(fd, buf, n);
 228        if (i < 0) {
 229                perror("write");
 230                exit(1);
 231        }
 232        if (i < n) {
 233                fprintf(stderr, "%s: write truncated\n", av[1]);
 234                exit(1);
 235        }
 236
 237        exit(0);
 238
 239 notelf:
 240        fprintf(stderr, "%s does not appear to be an ELF file\n", av[1]);
 241        exit(1);
 242
 243 nospace:
 244        fprintf(stderr, "sorry, I can't find space in %s to put the note\n",
 245                av[1]);
 246        exit(1);
 247}
 248