summaryrefslogtreecommitdiffstats
path: root/arch/ppc/boot/utils/addnote.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ppc/boot/utils/addnote.c')
-rw-r--r--arch/ppc/boot/utils/addnote.c175
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 000000000000..6c52b18f2d04
--- /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);
+}