arch/x86/boot/compressed/mkpiggy.c

   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;
  40
  41         if (argc < 2) {
  42                 fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
  43                 return 1;
  44         }
  45
  46         /* Get the information for the compressed kernel image first */
  47
  48         f = fopen(argv[1], "r");
  49         if (!f) {
  50                 perror(argv[1]);
  51                 return 1;
  52         }
  53
  54
  55         if (fseek(f, -4L, SEEK_END)) {
  56                 perror(argv[1]);
  57         }
  58
  59         if (fread(&olen, sizeof(olen), 1, f) != 1) {
  60                 perror(argv[1]);
  61                 return 1;
  62         }
  63
  64         ilen = ftell(f);
  65         olen = get_unaligned_le32(&olen);
  66         fclose(f);
  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         return 0;
  95 }