xref: /openbmc/linux/arch/x86/boot/compressed/mkpiggy.c (revision 12eb4683)
1 /* ----------------------------------------------------------------------- *
2  *
3  *  Copyright (C) 2009 Intel Corporation. All rights reserved.
4  *
5  *  This program is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU General Public License version
7  *  2 as published by the Free Software Foundation.
8  *
9  *  This program is distributed in the hope that it will be useful,
10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *  GNU General Public License for more details.
13  *
14  *  You should have received a copy of the GNU General Public License
15  *  along with this program; if not, write to the Free Software
16  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  *  02110-1301, USA.
18  *
19  *  H. Peter Anvin <hpa@linux.intel.com>
20  *
21  * ----------------------------------------------------------------------- */
22 
23 /*
24  * Compute the desired load offset from a compressed program; outputs
25  * a small assembly wrapper with the appropriate symbols defined.
26  */
27 
28 #include <stdlib.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include <inttypes.h>
32 #include <tools/le_byteshift.h>
33 
34 int main(int argc, char *argv[])
35 {
36 	uint32_t olen;
37 	long ilen;
38 	unsigned long offs;
39 	FILE *f = NULL;
40 	int retval = 1;
41 
42 	if (argc < 2) {
43 		fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
44 		goto bail;
45 	}
46 
47 	/* Get the information for the compressed kernel image first */
48 
49 	f = fopen(argv[1], "r");
50 	if (!f) {
51 		perror(argv[1]);
52 		goto bail;
53 	}
54 
55 
56 	if (fseek(f, -4L, SEEK_END)) {
57 		perror(argv[1]);
58 	}
59 
60 	if (fread(&olen, sizeof(olen), 1, f) != 1) {
61 		perror(argv[1]);
62 		goto bail;
63 	}
64 
65 	ilen = ftell(f);
66 	olen = get_unaligned_le32(&olen);
67 
68 	/*
69 	 * Now we have the input (compressed) and output (uncompressed)
70 	 * sizes, compute the necessary decompression offset...
71 	 */
72 
73 	offs = (olen > ilen) ? olen - ilen : 0;
74 	offs += olen >> 12;	/* Add 8 bytes for each 32K block */
75 	offs += 64*1024 + 128;	/* Add 64K + 128 bytes slack */
76 	offs = (offs+4095) & ~4095; /* Round to a 4K boundary */
77 
78 	printf(".section \".rodata..compressed\",\"a\",@progbits\n");
79 	printf(".globl z_input_len\n");
80 	printf("z_input_len = %lu\n", ilen);
81 	printf(".globl z_output_len\n");
82 	printf("z_output_len = %lu\n", (unsigned long)olen);
83 	printf(".globl z_extract_offset\n");
84 	printf("z_extract_offset = 0x%lx\n", offs);
85 	/* z_extract_offset_negative allows simplification of head_32.S */
86 	printf(".globl z_extract_offset_negative\n");
87 	printf("z_extract_offset_negative = -0x%lx\n", offs);
88 
89 	printf(".globl input_data, input_data_end\n");
90 	printf("input_data:\n");
91 	printf(".incbin \"%s\"\n", argv[1]);
92 	printf("input_data_end:\n");
93 
94 	retval = 0;
95 bail:
96 	if (f)
97 		fclose(f);
98 	return retval;
99 }
100