arch/m68k-all/dosboot/bootcode.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7 #include <libraries/configvars.h>
   8 #include <libraries/expansion.h>
   9 #include <libraries/expansionbase.h>
  10 #include <utility/tagitem.h>
  11 #include <dos/filehandler.h>
  12
  13 #include <proto/exec.h>
  14
  15 /*
  16  * Execute the code in the boot block.
  17  * This can be custom defined for your architecture.
  18  *
  19  * Returns 0 on success, or an error code
  20  */
  21 VOID_FUNC CallBootBlockCode(APTR bootcode, struct IOStdReq *io, struct ExpansionBase *ExpansionBase)
  22 {
  23     UBYTE oldflags = ExpansionBase->Flags & EBF_SILENTSTART;
  24     LONG retval;
  25     VOID_FUNC init;
  26
  27     D(bug("[Strap] Calling bootblock 0x%p!\n", bootcode));
  28
  29     ExpansionBase->Flags &= ~EBF_SILENTSTART;
  30
  31     /* Lovely. Double return values. What func. */
  32     asm volatile (
  33                  "move.l %2,%%a1\n"
  34                  "move.l %4,%%a0\n"
  35                  "move.l %%a6,%%sp@-\n"
  36                  "move.l %3,%%a6\n"
  37                  "jsr.l (%%a0)\n"
  38                  "move.l %%sp@+,%%a6\n"
  39                  "move.l %%d0,%0\n"
  40                  "move.l %%a0,%1\n"
  41                  : "=m" (retval), "=m" (init)
  42                  : "m" (io), "r" (SysBase),
  43                    "m" (bootcode)
  44                  : "%d0", "%d1", "%a0", "%a1");
  45     D(bug("bootblock: D0=0x%08x A0=%p\n", retval, init));
  46
  47     if (retval != 0)
  48     {
  49         D(bug("[Strap] Boot block failed to boot.\n"));
  50
  51         ExpansionBase->Flags |= oldflags;
  52         return NULL;
  53     }
  54
  55     return init;
  56 }
  57
  58 /* BootPoint booting, as describe in the Amiga Devices Manual */
  59 void dosboot_BootPoint(struct BootNode *bn)
  60 {
  61     struct DeviceNode *dn;
  62     struct FileSysStartupMsg *fssm;
  63     struct DosEnvec *de;
  64     IPTR bootblocks;
  65
  66     dn = bn->bn_DeviceNode;
  67     if (dn == NULL || dn->dn_Name == BNULL)
  68         return;
  69
  70     fssm = BADDR(dn->dn_Startup);
  71     if (fssm == NULL)
  72         return;
  73
  74     de = BADDR(fssm->fssm_Environ);
  75     if (de == NULL)
  76         return;
  77
  78     bootblocks = (de->de_TableSize < DE_BOOTBLOCKS) ? 0 : de->de_BootBlocks;
  79
  80     /* BootPoint nodes */
  81     if (bootblocks == 0 && bn->bn_Node.ln_Name != NULL)
  82     {
  83         struct ConfigDev *cd = (APTR)bn->bn_Node.ln_Name;
  84
  85         if (cd->cd_Rom.er_DiagArea != NULL)
  86         {
  87             struct DiagArea *da = cd->cd_Rom.er_DiagArea;
  88
  89             if (da->da_Config & DAC_CONFIGTIME)
  90             {
  91                 /* Yes, it's actually a BootPoint node */
  92                 void *func = (APTR)(((IPTR)da) + da->da_BootPoint);
  93
  94                 D(bug("dosboot_BootStrap: Calling %b BootPoint @%p\n", dn->dn_Name, func));
  95
  96                 /*
  97                  * Yet another crazy Amiga calling sequence.
  98                  * The ConfigDev is pushed on the stack, but
  99                  * the BootNode is in A2. Joy.
 100                  *
 101                  * Oh, and don't forget SysBase in A6!
 102                  */
 103                 asm volatile (
 104                         "move.l %0,%%a0\n"
 105                         "move.l %1,%%a1\n"
 106                         "move.l %2,%%a2\n"
 107                         "move.l %3,%%a6\n"
 108                         "move.l %%a1,%%sp@-\n"
 109                         "jsr    %%a0@\n"
 110                         "addq.l #4,%%sp\n"
 111                         :
 112                         : "d" (func), "d" (cd), "d" (bn), "d" (SysBase)
 113                         : "d0", "d1", "a0", "a1", "a2", "a6"
 114                         );
 115             }
 116         }
 117     }
 118 }