bsd/kern/mach_fat.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1991 NeXT Computer, Inc.  All rights reserved.
  23  *
  24  *      File:   kern/mach_fat.c
  25  *      Author: Peter King
  26  *
  27  *      Fat file support routines.
  28  *
  29  */
  30
  31 #include <sys/param.h>
  32 #include <sys/types.h>
  33 #include <sys/uio.h>
  34 #include <sys/vnode.h>
  35 #include <vm/vm_kern.h>
  36 #include <mach/kern_return.h>
  37 #include <mach/vm_param.h>
  38 #include <kern/cpu_number.h>
  39 #include <mach-o/fat.h>
  40 #include <kern/mach_loader.h>
  41 #include <architecture/byte_order.h>
  42
  43
  44 /**********************************************************************
  45  * Routine:     fatfile_getarch()
  46  *
  47  * Function:    Locate the architecture-dependant contents of a fat
  48  *              file that match this CPU.
  49  *
  50  * Args:        vp:             The vnode for the fat file.
  51  *              header:         A pointer to the fat file header.
  52  *              archret (out):  Pointer to fat_arch structure to hold
  53  *                              the results.
  54  *
  55  * Returns:     KERN_SUCCESS:   Valid architecture found.
  56  *              KERN_FAILURE:   No valid architecture found.
  57  **********************************************************************/
  58 load_return_t
  59 fatfile_getarch(
  60         struct vnode            *vp,
  61         vm_offset_t     data_ptr,
  62         struct fat_arch         *archret)
  63 {
  64         /* vm_pager_t           pager; */
  65         vm_offset_t             addr;
  66         vm_size_t               size;
  67         kern_return_t           kret;
  68         load_return_t           lret;
  69         struct machine_slot     *ms;
  70         struct fat_arch         *arch;
  71         struct fat_arch         *best_arch;
  72         int                     grade;
  73         int                     best_grade;
  74         int                     nfat_arch;
  75         int                     end_of_archs;
  76         struct fat_header       *header;
  77         off_t filesize;
  78
  79         /*
  80          *      Get the pager for the file.
  81          */
  82
  83         header = (struct fat_header *)data_ptr;
  84
  85         /*
  86          *      Map portion that must be accessible directly into
  87          *      kernel's map.
  88          */
  89         nfat_arch = NXSwapBigLongToHost(header->nfat_arch);
  90
  91         end_of_archs = sizeof(struct fat_header)
  92                 + nfat_arch * sizeof(struct fat_arch);
  93 #if 0
  94         filesize = ubc_getsize(vp);
  95         if (end_of_archs > (int)filesize) {
  96                 return(LOAD_BADMACHO);
  97         }
  98 #endif
  99
 100         /* This is beacuse we are reading only 512 bytes */
 101
 102         if (end_of_archs > 512)
 103                 return(LOAD_BADMACHO);
 104         /*
 105          *      Round size of fat_arch structures up to page boundry.
 106          */
 107         size = round_page(end_of_archs);
 108         if (size <= 0)
 109                 return(LOAD_BADMACHO);
 110
 111         /*
 112          * Scan the fat_arch's looking for the best one.
 113          */
 114         addr = data_ptr;
 115         ms = &machine_slot[cpu_number()];
 116         best_arch = NULL;
 117         best_grade = 0;
 118         arch = (struct fat_arch *) (addr + sizeof(struct fat_header));
 119         for (; nfat_arch-- > 0; arch++) {
 120
 121                 /*
 122                  *      Check to see if right cpu type.
 123                  */
 124                 if(NXSwapBigIntToHost(arch->cputype) != ms->cpu_type)
 125                         continue;
 126
 127                 /*
 128                  *      Get the grade of the cpu subtype.
 129                  */
 130                 grade = grade_cpu_subtype(
 131                             NXSwapBigIntToHost(arch->cpusubtype));
 132
 133                 /*
 134                  *      Remember it if it's the best we've seen.
 135                  */
 136                 if (grade > best_grade) {
 137                         best_grade = grade;
 138                         best_arch = arch;
 139                 }
 140         }
 141
 142         /*
 143          *      Return our results.
 144          */
 145         if (best_arch == NULL) {
 146                 lret = LOAD_BADARCH;
 147         } else {
 148                 archret->cputype        =
 149                             NXSwapBigIntToHost(best_arch->cputype);
 150                 archret->cpusubtype     =
 151                             NXSwapBigIntToHost(best_arch->cpusubtype);
 152                 archret->offset         =
 153                             NXSwapBigLongToHost(best_arch->offset);
 154                 archret->size           =
 155                             NXSwapBigLongToHost(best_arch->size);
 156                 archret->align          =
 157                             NXSwapBigLongToHost(best_arch->align);
 158
 159                 lret = LOAD_SUCCESS;
 160         }
 161
 162         /*
 163          * Free the memory we allocated and return.
 164          */
 165         return(lret);
 166 }
 167
 168