arch/.unmaintained/arm-all/exec/preparecontext.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <exec/types.h>
   7 #include <aros/libcall.h>
   8 #include <exec/execbase.h>
   9 #include <exec/tasks.h>
  10 #include <exec/memory.h>
  11 #include <exec/ptrace.h>
  12
  13 #include "exec_util.h"
  14
  15 #define DEBUG 1
  16 #include <aros/debug.h>
  17
  18 #error "PrepareContext() has been changed. Additional tagList param, etc."
  19 #error "This one here needs to be rewritten!"
  20
  21 BOOL PrepareContext(struct Task *task, APTR entryPoint, APTR fallBack,
  22                     struct TagItem *tagList, struct ExecBase *SysBase)
  23 {
  24     struct pt_regs *regs;
  25
  26     ULONG *sp = (ULONG *)task->tc_SPReg;
  27     ULONG * armregs;
  28     ULONG i = 0;
  29
  30     if (!(task->tc_Flags & TF_ETASK)) {
  31         return FALSE;
  32     }
  33
  34     task->tc_UnionETask.tc_ETask->et_RegFrame = AllocTaskMem (task, SIZEOF_ALL_REGISTERS,
  35                                                               MEMF_PUBLIC|MEMF_CLEAR);
  36
  37     if (!(regs  = (struct pt_regs *)task->tc_UnionETask.tc_ETask->et_RegFrame))
  38         return FALSE;
  39
  40     /*
  41      * Fill the registers r0-r3 with the arguments on the stack -
  42      * if there are any...
  43      */
  44     armregs = &regs->r0;
  45 #if 0
  46     D(bug("sp=%x, task->tc_SPUpper=%x, name=%s\n",
  47           sp,
  48           task->tc_SPUpper,
  49           task->tc_Node.ln_Name));
  50 #endif
  51     if (sp < (ULONG *)task->tc_SPUpper) {
  52         while (sp < (ULONG *)task->tc_SPUpper && i < 4) {
  53 //          D(bug("before: armregs=%x, sp=%x\n",armregs,sp));
  54             *armregs = *sp;
  55             armregs++;
  56             sp++;
  57             i++;
  58 //          D(bug("after: armregs=%x, sp=%x\n",armregs,sp));
  59         }
  60         sp--;
  61     }
  62
  63     /*
  64      * Initialize initial registers. Only sp and lr_svc
  65      * are important. lr_svc represents the entry point of
  66      * the process plus 4. The 4 will be subtracted automatically
  67      * when the process is started. It must be done that way
  68      * due to how the ARM processor works when handling *interrupts*!
  69      * Also set the processor for User Mode.
  70      */
  71     regs->sp      = sp;
  72     regs->lr_svc  = (ULONG)entryPoint+4;
  73     regs->cpsr    = (ULONG)0x10;
  74
  75     /*
  76      * Now I am not sure whether this is going to work.
  77      * In the *startup* code I will need to make sure
  78      * that the fallback can be executed!
  79      * Note that no '4' needs to be added in this case!
  80      */
  81     regs->lr      = (ULONG)fallBack;
  82
  83     return TRUE;
  84 }