diff options
Diffstat (limited to 'arch/ppc/boot/utils/addnote.c')
| -rw-r--r-- | arch/ppc/boot/utils/addnote.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/arch/ppc/boot/utils/addnote.c b/arch/ppc/boot/utils/addnote.c new file mode 100644 index 0000000..6c52b18 --- /dev/null +++ b/arch/ppc/boot/utils/addnote.c @@ -0,0 +1,175 @@ +/* + * Program to hack in a PT_NOTE program header entry in an ELF file. + * This is needed for OF on RS/6000s to load an image correctly. + * Note that OF needs a program header entry for the note, not an + * ELF section. + * + * Copyright 2000 Paul Mackerras. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Usage: addnote zImage + */ +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> + +char arch[] = "PowerPC"; + +#define N_DESCR 6 +unsigned int descr[N_DESCR] = { +#if 1 + /* values for IBM RS/6000 machines */ + 0xffffffff, /* real-mode = true */ + 0x00c00000, /* real-base, i.e. where we expect OF to be */ + 0xffffffff, /* real-size */ + 0xffffffff, /* virt-base */ + 0xffffffff, /* virt-size */ + 0x4000, /* load-base */ +#else + /* values for longtrail CHRP */ + 0, /* real-mode = false */ + 0xffffffff, /* real-base */ + 0xffffffff, /* real-size */ + 0xffffffff, /* virt-base */ + 0xffffffff, /* virt-size */ + 0x00600000, /* load-base */ +#endif +}; + +unsigned char buf[512]; + +#define GET_16BE(off) ((buf[off] << 8) + (buf[(off)+1])) +#define GET_32BE(off) ((GET_16BE(off) << 16) + GET_16BE((off)+2)) + +#define PUT_16BE(off, v) (buf[off] = ((v) >> 8) & 0xff, \ + buf[(off) + 1] = (v) & 0xff) +#define PUT_32BE(off, v) (PUT_16BE((off), (v) >> 16), \ + PUT_16BE((off) + 2, (v))) + +/* Structure of an ELF file */ +#define E_IDENT 0 /* ELF header */ +#define E_PHOFF 28 +#define E_PHENTSIZE 42 +#define E_PHNUM 44 +#define E_HSIZE 52 /* size of ELF header */ + +#define EI_MAGIC 0 /* offsets in E_IDENT area */ +#define EI_CLASS 4 +#define EI_DATA 5 + +#define PH_TYPE 0 /* ELF program header */ +#define PH_OFFSET 4 +#define PH_FILESZ 16 +#define PH_HSIZE 32 /* size of program header */ + +#define PT_NOTE 4 /* Program header type = note */ + +#define ELFCLASS32 1 +#define ELFDATA2MSB 2 + +unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' }; + +int main(int ac, char **av) +{ + int fd, n, i; + int ph, ps, np; + int nnote, ns; + + if (ac != 2) { + fprintf(stderr, "Usage: %s elf-file\n", av[0]); + exit(1); + } + fd = open(av[1], O_RDWR); + if (fd < 0) { + perror(av[1]); + exit(1); + } + + nnote = strlen(arch) + 1 + (N_DESCR + 3) * 4; + + n = read(fd, buf, sizeof(buf)); + if (n < 0) { + perror("read"); + exit(1); + } + + if (n < E_HSIZE || memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0) + goto notelf; + + if (buf[E_IDENT+EI_CLASS] != ELFCLASS32 + || buf[E_IDENT+EI_DATA] != ELFDATA2MSB) { + fprintf(stderr, "%s is not a big-endian 32-bit ELF image\n", + av[1]); + exit(1); + } + + ph = GET_32BE(E_PHOFF); + ps = GET_16BE(E_PHENTSIZE); + np = GET_16BE(E_PHNUM); + if (ph < E_HSIZE || ps < PH_HSIZE || np < 1) + goto notelf; + if (ph + (np + 1) * ps + nnote > n) + goto nospace; + + for (i = 0; i < np; ++i) { + if (GET_32BE(ph + PH_TYPE) == PT_NOTE) { + fprintf(stderr, "%s already has a note entry\n", + av[1]); + exit(0); + } + ph += ps; + } + + /* XXX check that the area we want to use is all zeroes */ + for (i = 0; i < ps + nnote; ++i) + if (buf[ph + i] != 0) + goto nospace; + + /* fill in the program header entry */ + ns = ph + ps; + PUT_32BE(ph + PH_TYPE, PT_NOTE); + PUT_32BE(ph + PH_OFFSET, ns); + PUT_32BE(ph + PH_FILESZ, nnote); + + /* fill in the note area we point to */ + /* XXX we should probably make this a proper section */ + PUT_32BE(ns, strlen(arch) + 1); + PUT_32BE(ns + 4, N_DESCR * 4); + PUT_32BE(ns + 8, 0x1275); + strcpy(&buf[ns + 12], arch); + ns += 12 + strlen(arch) + 1; + for (i = 0; i < N_DESCR; ++i) + PUT_32BE(ns + i * 4, descr[i]); + + /* Update the number of program headers */ + PUT_16BE(E_PHNUM, np + 1); + + /* write back */ + lseek(fd, (long) 0, SEEK_SET); + i = write(fd, buf, n); + if (i < 0) { + perror("write"); + exit(1); + } + if (i < n) { + fprintf(stderr, "%s: write truncated\n", av[1]); + exit(1); + } + + exit(0); + + notelf: + fprintf(stderr, "%s does not appear to be an ELF file\n", av[0]); + exit(1); + + nospace: + fprintf(stderr, "sorry, I can't find space in %s to put the note\n", + av[0]); + exit(1); +} |
