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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/ppc64/boot/addnote.c
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
7 * Copyright 2000 Paul Mackerras.
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.
14 * Usage: addnote zImage
22 char arch
[] = "PowerPC";
25 unsigned int descr
[N_DESCR
] = {
26 0xffffffff, /* real-mode = true */
27 0x00c00000, /* real-base, i.e. where we expect OF to be */
28 0xffffffff, /* real-size */
29 0xffffffff, /* virt-base */
30 0xffffffff, /* virt-size */
31 0x4000, /* load-base */
34 unsigned char buf
[512];
36 #define GET_16BE(off) ((buf[off] << 8) + (buf[(off)+1]))
37 #define GET_32BE(off) ((GET_16BE(off) << 16) + GET_16BE((off)+2))
39 #define PUT_16BE(off, v) (buf[off] = ((v) >> 8) & 0xff, \
40 buf[(off) + 1] = (v) & 0xff)
41 #define PUT_32BE(off, v) (PUT_16BE((off), (v) >> 16), \
42 PUT_16BE((off) + 2, (v)))
44 /* Structure of an ELF file */
45 #define E_IDENT 0 /* ELF header */
47 #define E_PHENTSIZE 42
49 #define E_HSIZE 52 /* size of ELF header */
51 #define EI_MAGIC 0 /* offsets in E_IDENT area */
55 #define PH_TYPE 0 /* ELF program header */
58 #define PH_HSIZE 32 /* size of program header */
60 #define PT_NOTE 4 /* Program header type = note */
65 unsigned char elf_magic
[4] = { 0x7f, 'E', 'L', 'F' };
68 main(int ac
, char **av
)
75 fprintf(stderr
, "Usage: %s elf-file\n", av
[0]);
78 fd
= open(av
[1], O_RDWR
);
84 nnote
= strlen(arch
) + 1 + (N_DESCR
+ 3) * 4;
86 n
= read(fd
, buf
, sizeof(buf
));
92 if (n
< E_HSIZE
|| memcmp(&buf
[E_IDENT
+EI_MAGIC
], elf_magic
, 4) != 0)
95 if (buf
[E_IDENT
+EI_CLASS
] != ELFCLASS32
96 || buf
[E_IDENT
+EI_DATA
] != ELFDATA2MSB
) {
97 fprintf(stderr
, "%s is not a big-endian 32-bit ELF image\n",
102 ph
= GET_32BE(E_PHOFF
);
103 ps
= GET_16BE(E_PHENTSIZE
);
104 np
= GET_16BE(E_PHNUM
);
105 if (ph
< E_HSIZE
|| ps
< PH_HSIZE
|| np
< 1)
107 if (ph
+ (np
+ 1) * ps
+ nnote
> n
)
110 for (i
= 0; i
< np
; ++i
) {
111 if (GET_32BE(ph
+ PH_TYPE
) == PT_NOTE
) {
112 fprintf(stderr
, "%s already has a note entry\n",
119 /* XXX check that the area we want to use is all zeroes */
120 for (i
= 0; i
< ps
+ nnote
; ++i
)
121 if (buf
[ph
+ i
] != 0)
124 /* fill in the program header entry */
126 PUT_32BE(ph
+ PH_TYPE
, PT_NOTE
);
127 PUT_32BE(ph
+ PH_OFFSET
, ns
);
128 PUT_32BE(ph
+ PH_FILESZ
, nnote
);
130 /* fill in the note area we point to */
131 /* XXX we should probably make this a proper section */
132 PUT_32BE(ns
, strlen(arch
) + 1);
133 PUT_32BE(ns
+ 4, N_DESCR
* 4);
134 PUT_32BE(ns
+ 8, 0x1275);
135 strcpy(&buf
[ns
+ 12], arch
);
136 ns
+= 12 + strlen(arch
) + 1;
137 for (i
= 0; i
< N_DESCR
; ++i
)
138 PUT_32BE(ns
+ i
* 4, descr
[i
]);
140 /* Update the number of program headers */
141 PUT_16BE(E_PHNUM
, np
+ 1);
144 lseek(fd
, (long) 0, SEEK_SET
);
145 i
= write(fd
, buf
, n
);
151 fprintf(stderr
, "%s: write truncated\n", av
[1]);
158 fprintf(stderr
, "%s does not appear to be an ELF file\n", av
[0]);
162 fprintf(stderr
, "sorry, I can't find space in %s to put the note\n",