Prevent Aborts from happening whilst emulating a SWI

diff --git a/sim/arm/ChangeLog b/sim/arm/ChangeLog
index ac6e453..a5820c3 100644 (file)
--- a/sim/arm/ChangeLog
+++ b/sim/arm/ChangeLog
@@ -1,3 +1,10 @@
+2001-02-13  Nick Clifton  <nickc@redhat.com>
+
+       * armos.c (in_SWI_handler): New static variable.
+       (ARMul_OSHandleSWI): Set in_SWI_handler whilst emulating a SWI.
+       (ARMul_OSException): Ignore exceptions generated whilst emulating
+       a SWI.
+
 2001-02-12  Nick Clifton  <nickc@redhat.com>
 
        * armemu.h (NEGBRANCH): Fix defintion.

diff --git a/sim/arm/armos.c b/sim/arm/armos.c
index 789a35d..6545cc8 100644 (file)
--- a/sim/arm/armos.c
+++ b/sim/arm/armos.c
@@ -139,6 +139,10 @@ static ARMword softvectorcode[] =
   0xe1a0f00e                   /* Default handler */
 };
 
+
+/* Set to prevent aborts when emulating SWI routines.  */
+static int in_SWI_handler = 0;
+
 /* Time for the Operating System to initialise itself.  */
 
 unsigned
@@ -385,10 +389,13 @@ SWIflen (ARMul_State * state, ARMword fh)
 unsigned
 ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
 {
-  ARMword addr, temp;
-  struct OSblock *OSptr = (struct OSblock *) state->OSptr;
-  ARMword saved_number = 0;
+  ARMword          addr;
+  ARMword          temp;
+  ARMword          saved_number = 0;
+  struct OSblock * OSptr = (struct OSblock *) state->OSptr;
   
+  in_SWI_handler = 1;
+
   /* Intel do not want DEMON SWI support.  */
   if (state->is_XScale)
     switch (number)
@@ -416,15 +423,15 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
     {
     case SWI_Read:
       SWIread (state, state->Reg[0], state->Reg[1], state->Reg[2]);
-      return TRUE;
+      break;
 
     case SWI_Write:
       SWIwrite (state, state->Reg[0], state->Reg[1], state->Reg[2]);
-      return TRUE;
+      break;
 
     case SWI_Open:
       SWIopen (state, state->Reg[0], state->Reg[1]);
-      return TRUE;
+      break;
 
     case SWI_Clock:
       /* Return number of centi-seconds.  */
@@ -438,46 +445,44 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
        (ARMword) (clock () / 10000);
 #endif
       OSptr->ErrorNo = errno;
-      return TRUE;
+      break;
 
     case SWI_Time:
       state->Reg[0] = (ARMword) time (NULL);
       OSptr->ErrorNo = errno;
-      return TRUE;
+      break;
 
     case SWI_Close:
       state->Reg[0] = close (state->Reg[0]);
       OSptr->ErrorNo = errno;
-      return TRUE;
+      break;
 
     case SWI_Flen:
       SWIflen (state, state->Reg[0]);
-      return TRUE;
+      break;
 
     case SWI_Exit:
       state->Emulate = FALSE;
-      return TRUE;
+      break;
 
     case SWI_Seek:
-      {
-       /* We must return non-zero for failure.  */
-       state->Reg[0] = -1 >= lseek (state->Reg[0], state->Reg[1], SEEK_SET);
-       OSptr->ErrorNo = errno;
-       return TRUE;
-      }
+      /* We must return non-zero for failure.  */
+      state->Reg[0] = -1 >= lseek (state->Reg[0], state->Reg[1], SEEK_SET);
+      OSptr->ErrorNo = errno;
+      break;
 
     case SWI_WriteC:
       (void) fputc ((int) state->Reg[0], stdout);
       OSptr->ErrorNo = errno;
-      return TRUE;
+      break;
 
     case SWI_Write0:
       SWIWrite0 (state, state->Reg[0]);
-      return TRUE;
+      break;
 
     case SWI_GetErrno:
       state->Reg[0] = OSptr->ErrorNo;
-      return TRUE;
+      break;
 
     case SWI_GetEnv:
       state->Reg[0] = ADDRCMDLINE;
@@ -487,12 +492,12 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
        state->Reg[1] = ADDRUSERSTACK;
 
       WriteCommandLineTo (state, state->Reg[0]);
-      return TRUE;
+      break;
 
     case SWI_Breakpoint:
       state->EndCondition = RDIError_BreakpointReached;
       state->Emulate = FALSE;
-      return TRUE;
+      break;
 
       /* Handle Angel SWIs as well as Demon ones.  */
     case AngelSWI_ARM:
@@ -512,6 +517,7 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
        case AngelSWI_Reason_EnterSVC:
        default:
          state->Emulate = FALSE;
+         in_SWI_handler = 0;
          return FALSE;
 
        case AngelSWI_Reason_Clock:
@@ -526,41 +532,40 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
            (ARMword) (clock () / 10000);
 #endif
          OSptr->ErrorNo = errno;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Time:
          state->Reg[0] = (ARMword) time (NULL);
          OSptr->ErrorNo = errno;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_WriteC:
          (void) fputc ((int) ARMul_ReadByte (state, addr), stdout);
          OSptr->ErrorNo = errno;
-         return TRUE;
 
        case AngelSWI_Reason_Write0:
          SWIWrite0 (state, addr);
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Close:
          state->Reg[0] = close (ARMul_ReadWord (state, addr));
          OSptr->ErrorNo = errno;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Seek:
          state->Reg[0] = -1 >= lseek (ARMul_ReadWord (state, addr),
                                       ARMul_ReadWord (state, addr + 4),
                                       SEEK_SET);
          OSptr->ErrorNo = errno;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_FLen:
          SWIflen (state, ARMul_ReadWord (state, addr));
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_GetCmdLine:
          WriteCommandLineTo (state, ARMul_ReadWord (state, addr));
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_HeapInfo:
          /* R1 is a pointer to a pointer.  */
@@ -576,7 +581,7 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
          ARMul_WriteWord (state, addr + 4, temp);      /* Heap limit */
          ARMul_WriteWord (state, addr + 8, temp);      /* Stack base */
          ARMul_WriteWord (state, addr + 12, temp);     /* Stack limit */
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_ReportException:
          if (state->Reg[1] == ADP_Stopped_ApplicationExit)
@@ -584,79 +589,84 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
          else
            state->Reg[0] = -1;
          state->Emulate = FALSE;
-         return TRUE;
+         break;
 
        case ADP_Stopped_ApplicationExit:
          state->Reg[0] = 0;
          state->Emulate = FALSE;
-         return TRUE;
+         break;
 
        case ADP_Stopped_RunTimeError:
          state->Reg[0] = -1;
          state->Emulate = FALSE;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Errno:
          state->Reg[0] = OSptr->ErrorNo;
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Open:
          SWIopen (state,
                   ARMul_ReadWord (state, addr),
                   ARMul_ReadWord (state, addr + 4));
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Read:
          SWIread (state,
                   ARMul_ReadWord (state, addr),
                   ARMul_ReadWord (state, addr + 4),
                   ARMul_ReadWord (state, addr + 8));
-         return TRUE;
+         break;
 
        case AngelSWI_Reason_Write:
          SWIwrite (state,
                    ARMul_ReadWord (state, addr),
                    ARMul_ReadWord (state, addr + 4),
                    ARMul_ReadWord (state, addr + 8));
-         return TRUE;
+         break;
        }
 
     case 0x90:
     case 0x91:
     case 0x92:
       /* These are used by the FPE code.  */
-      return TRUE;
+      break;
       
     default:
-      {
-       /* If there is a SWI vector installed use it.  */
-       if (state->is_XScale && saved_number != -1)
-         number = saved_number;
+      in_SWI_handler = 0;
+      
+      /* If there is a SWI vector installed use it.  */
+      if (state->is_XScale && saved_number != -1)
+       number = saved_number;
            
-       if (SWI_vector_installed && number != SWI_Breakpoint)
-         {
-           ARMword cpsr;
-           ARMword i_size;
+      if (SWI_vector_installed && number != SWI_Breakpoint)
+       {
+         ARMword cpsr;
+         ARMword i_size;
            
-           cpsr = ARMul_GetCPSR (state);
-           i_size = INSN_SIZE;
+         cpsr = ARMul_GetCPSR (state);
+         i_size = INSN_SIZE;
            
-           ARMul_SetSPSR (state, SVC32MODE, cpsr);
+         ARMul_SetSPSR (state, SVC32MODE, cpsr);
            
-           cpsr &= ~0xbf;
-           cpsr |= SVC32MODE | 0x80;
-           ARMul_SetCPSR (state, cpsr);
+         cpsr &= ~0xbf;
+         cpsr |= SVC32MODE | 0x80;
+         ARMul_SetCPSR (state, cpsr);
            
-           state->RegBank[SVCBANK][14] = state->Reg[14] = state->Reg[15] - i_size;
-           state->NextInstr            = RESUME;
-           state->Reg[15]              = state->pc = ARMSWIV;
-           FLUSHPIPE;
-         }
-       else
+         state->RegBank[SVCBANK][14] = state->Reg[14] = state->Reg[15] - i_size;
+         state->NextInstr            = RESUME;
+         state->Reg[15]              = state->pc = ARMSWIV;
+         FLUSHPIPE;
+       }
+      else
+       {
          fprintf (stderr, "unknown SWI encountered - %x - ignoring\n", number);
-       return TRUE;
-      }
+         return FALSE;
+       }
     }
+
+  in_SWI_handler = 0;
+  return TRUE;
 }
 
 #ifndef NOOS
@@ -672,7 +682,11 @@ ARMul_OSException (ARMul_State * state  ATTRIBUTE_UNUSED,
                   ARMword       vector ATTRIBUTE_UNUSED,
                   ARMword       pc     ATTRIBUTE_UNUSED)
 {
-  return FALSE;
+  /* If we are inside a SWI handler routine, then ignore any exceptions.
+     They could be caused by data exceptions for misaligned reads, for
+     example, but for the purposes of emulating a SWI, we do not care.  */
+   
+  return in_SWI_handler;
 }
 
 #endif