rom/dos/isbootable.c

   1 /*
   2     Copyright © 1995-2016, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Can this disk boot on your architecture?
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10 #include <exec/alerts.h>
  11 #include <proto/exec.h>
  12 #include <proto/dos.h>
  13
  14 #include "dos_intern.h"
  15
  16 /* Signature file, contains (for example) 'pc-i386' */
  17 #define AROS_BOOT_CHECKSIG ":AROS.boot"
  18 /* Alternate variant: check if Shell is loadable
  19 #define AROS_BOOT_CHECKEXEC ":C/Shell" */
  20
  21 BOOL __dos_IsBootable(struct DosLibrary * DOSBase, BPTR lock)
  22 {
  23 #if defined(AROS_BOOT_CHECKSIG)
  24     BPTR fh;
  25     STRPTR buffer;
  26     LONG bufferLength;
  27     struct FileInfoBlock *abfile_fib;
  28     BOOL result = FALSE;
  29
  30     D(bug("[__dos_IsBootable] __dos_IsBootable('%s')\n", AROS_BOOT_CHECKSIG));
  31
  32     CurrentDir(lock);
  33     fh = Open(AROS_BOOT_CHECKSIG, MODE_OLDFILE);
  34     if (!fh)
  35     {
  36 #ifdef __mc68000
  37         /*
  38          * Original Amiga disks don't contain this signature. They are obviously bootable on m68k.
  39          * However if the disk DOES contain a signature, we should check it. This can happen to be
  40          * a disk for another architecture. Attempting to boot from it will cause crash.
  41          */
  42         return TRUE;
  43 #else
  44         return FALSE;
  45 #endif
  46     }
  47
  48     D(bug("[__dos_IsBootable] Opened successfully\n"));
  49
  50     abfile_fib = AllocDosObject(DOS_FIB, NULL);
  51     if (abfile_fib)
  52     {
  53         if (ExamineFH(fh, abfile_fib))
  54         {
  55             LONG readsize;
  56
  57             bufferLength = abfile_fib->fib_Size + 1;
  58
  59             buffer = AllocMem(bufferLength, MEMF_ANY);
  60             D(bug("[__dos_IsBootable] Allocated %d bytes for Buffer @ %p\n", bufferLength, buffer));
  61
  62             if (!buffer)
  63             {
  64                 Alert(AT_DeadEnd | AG_NoMemory | AN_DOSLib);
  65             }
  66
  67             readsize = Read(fh, buffer, bufferLength - 1);
  68             if (readsize > 0)
  69             {
  70                 char *sigptr = NULL;
  71
  72                 buffer[readsize] = '\0';
  73                 D(bug("[__dos_IsBootable] Buffer contains '%s'\n", buffer));
  74
  75                 if ((sigptr = strstr(buffer, AROS_CPU)) != 0)
  76                 {
  77                     D(bug("[__dos_IsBootable] Signature '%s' found\n", AROS_CPU));
  78                     result = TRUE;
  79                 }
  80                 else
  81                 {
  82                     /* Something to more or less reflect "This disk is not bootable" */
  83                     SetIoErr(ERROR_OBJECT_WRONG_TYPE);
  84                 }
  85             }
  86         }
  87         FreeDosObject(DOS_FIB, abfile_fib);
  88     }
  89
  90     Close(fh);
  91
  92     D(bug("[__dos_IsBootable] returned %d\n", result));
  93     return result;
  94
  95 #elif defined(AROS_BOOT_CHECKEXEC)
  96     BPTR seg;
  97
  98     D(bug("[__dos_IsBootable]: Trying to load '%s' as an executable\n", AROS_BOOT_CHECKEXEC));
  99
 100     CurrentDir(lock);
 101     if ((seg = LoadSeg(AROS_BOOT_CHECKEXEC)))
 102     {
 103         UnLoadSeg(seg);
 104
 105         D(bug("[__dos_IsBootable] Success!\n"));
 106         return TRUE;
 107     }
 108
 109 #else
 110     return TRUE;
 111 #endif
 112 }