workbench/devs/networks/atheros5000/hal/public/wackelf.c

   1 /*
   2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
   3  * Copyright (c) 2002-2008 Atheros Communications, Inc.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  *
  17  * $Id$
  18  */
  19
  20 /*
  21  * Program to zap flags field in the ELF header of an object
  22  * file so that it appears to use VFP soft floating point.
  23  * This is done because there is no standard way to specify
  24  * this on the command line to gcc/binutils.
  25  *
  26  * Derived from code by Olivier Houchard <cognet@freebsd.org>
  27  */
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <elf.h>
  31 #include <fcntl.h>
  32 #include <err.h>
  33
  34 #ifdef __linux__
  35 #include <endian.h>
  36 #include <byteswap.h>
  37 #define _LITTLE_ENDIAN  __LITTLE_ENDIAN
  38 #define _BIG_ENDIAN     __BIG_ENDIAN
  39 #if __BYTE_ORDER == __LITTLE_ENDIAN
  40 #define htobe16(x)      __bswap_16((x))
  41 #define htobe32(x)      __bswap_32((x))
  42 #define htole16(x)      ((uint16_t)(x))
  43 #define htole32(x)      ((uint32_t)(x))
  44 #else /* _BYTE_ORDER != _LITTLE_ENDIAN */
  45 #define htobe16(x)      ((uint16_t)(x))
  46 #define htobe32(x)      ((uint32_t)(x))
  47 #define htole16(x)      __bswap_16((x))
  48 #define htole32(x)      __bswap_32((x))
  49 #endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
  50 #else
  51 #include <sys/endian.h>
  52 #endif
  53
  54 int
  55 main(int argc, char *argv[])
  56 {
  57         int fd, endian, oflags;
  58         int format = 0x400;             /* default to VFP */
  59         Elf32_Ehdr ehdr;
  60
  61         if (argc > 2) {
  62                 if (strcmp(argv[1], "-fpa") == 0) {
  63                         format = 0x200;
  64                         argc--, argv++;
  65                 } else if (strcmp(argv[1], "-vfp") == 0) {
  66                         format = 0x400;
  67                         argc--, argv++;
  68                 } else if (strcmp(argv[1], "-none") == 0) {
  69                         format = 0;
  70                         argc--, argv++;
  71                 }
  72         }
  73         if (argc != 2) {
  74                 fprintf(stderr, "usage: %s [-fpa|-vfp|-none] file\n", argv[0]);
  75                 exit(-1);
  76         }
  77         fd = open(argv[1], O_RDWR);
  78         if (fd < 0)
  79                 err(1, "could not open %s", argv[1]);
  80         if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
  81                 err(1, "could not read the ELF header");
  82         if (ehdr.e_machine == htole16(EM_ARM))
  83                 endian = _LITTLE_ENDIAN;
  84         else if (ehdr.e_machine == htobe16(EM_ARM))
  85                 endian = _BIG_ENDIAN;
  86         else
  87                 errx(1, "not an ARM ELF object (machine 0x%x)", ehdr.e_machine);
  88         oflags = ehdr.e_flags;
  89         if (endian == _BIG_ENDIAN) {
  90                 ehdr.e_flags &= ~htobe32(0x600); /* Remove FPA Soft float */
  91                 ehdr.e_flags |= htobe32(format); /* VFP Soft Float */
  92         } else {
  93                 ehdr.e_flags &= ~htole32(0x600); /* Remove FPA Soft float */
  94                 ehdr.e_flags |= htole32(format); /* VFP Soft Float */
  95         }
  96         printf("%s: e_flags 0x%x => 0x%x\n", argv[1], oflags, ehdr.e_flags);
  97         if (lseek(fd, (off_t) 0, SEEK_SET) != 0)
  98                 err(1, "lseek");
  99         if (write(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
 100                 err(1, "yow, elf header write failed");
 101         close(fd);
 102         return 0;
 103 }