Add support for disabling alignment checks when performing GDB interface

calls or SWI emulaiton routines.  (Alignment checking code has not yet been
contributed).

8 files changed, 95 insertions, 44 deletions

diff --git a/sim/arm/ChangeLog b/sim/arm/ChangeLog
index 7ed494d19ab..fd11ec17cf2 100644
--- a/sim/arm/ChangeLog
+++ b/sim/arm/ChangeLog
@@ -1,3 +1,33 @@
+2001-02-27  Nick Clifton  <nickc@redhat.com>
+
+	* armvirt.c (GetWord): Add new parameter - check - to enable or
+	disable the alignment checking.
+	(PutWord):  Add new parameter - check - to enable or disable the
+	alignment checking.
+	(ARMul_ReLoadInstr): Pass extra parameter to GetWord.
+	(ARMul_ReadWord): Pass extra parameter to GetWord.
+	(ARMul_WriteWord): Pass extra parameter to PutWord.
+	(ARMul_StoreHalfWord): Pass extra parameter to PutWord.
+	(ARMul_WriteByte): Pass extra parameter to GetWord.
+	(ARMul_SwapWord): Pass extra parameter to PutWord.
+	(ARMul_SafeReadByte): New Function: Read a byte but do not abort.
+	(ARMul_SafeWriteByte): New Function: Write a byte but do not abort.
+	
+	* armdefs.h: Add prototypes for ARMul_SafeReadByte and
+	ARMul_SafeWriteByte.
+	
+	* wrapper.c (sim_write): Use ARMul_SafeWriteByte.
+	(sim_read): Use ARMul_SafeReadByte.
+
+	* armos.c (in_SWI_handler): Remove.
+	(SWIWrite0): Use ARMul_SafeReadByte.
+	(WriteCommandLineTo): Use ARMul_SafeWriteByte.
+	(SWIopen): Use ARMul_SafeReadByte.
+	(SWIread): Use ARMul_SafeWriteByte.
+	(SWIwrite): Use ARMul_SafeReadByte.
+	(ARMul_OSHandleSWI): Remove use of is_SWI_handler.
+	(ARMul_OSException): Remove use of is_SWI_handler.
+	
 2001-02-16  Nick Clifton  <nickc@redhat.com>
 
 	* armemu.c: Remove Prefetch abort for breakpoints.  Instead set
diff --git a/sim/arm/armcopro.c b/sim/arm/armcopro.c
index db7ee60d69c..8605dcfbeec 100644
--- a/sim/arm/armcopro.c
+++ b/sim/arm/armcopro.c
@@ -16,6 +16,7 @@
     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
 
 #include "armdefs.h"
+#include "armos.h"
 #include "armemu.h"
 #include "ansidecl.h"
 
@@ -211,7 +212,7 @@ check_cp15_access (ARMul_State * state,
 /* Store a value into one of coprocessor 15's registers.  */
 
 void
-write_cp15_reg (unsigned reg, unsigned opcode_2, unsigned CRm, ARMword value)
+write_cp15_reg (ARMul_State * state, unsigned reg, unsigned opcode_2, unsigned CRm, ARMword value)
 {
   if (opcode_2)
     {
@@ -324,9 +325,9 @@ write_cp15_reg (unsigned reg, unsigned opcode_2, unsigned CRm, ARMword value)
   return;
 }
 
-/* Return the value in a cp13 register.  */
+/* Return the value in a cp15 register.  */
 
-static ARMword
+ARMword
 read_cp15_reg (unsigned reg, unsigned opcode_2, unsigned CRm)
 {
   if (opcode_2 == 0)
@@ -364,7 +365,7 @@ XScale_cp15_LDC (ARMul_State * state, unsigned type, ARMword instr, ARMword data
   result = check_cp15_access (state, reg, 0, 0, 0);
   
   if (result == ARMul_DONE && type == ARMul_DATA)
-    write_cp15_reg (reg, 0, 0, data);
+    write_cp15_reg (state, reg, 0, 0, data);
 
   return result;
 }
@@ -416,7 +417,7 @@ XScale_cp15_MCR (ARMul_State * state,
   result = check_cp15_access (state, reg, CRm, BITS (21, 23), opcode_2);
   
   if (result == ARMul_DONE)
-    write_cp15_reg (reg, opcode_2, CRm, value);
+    write_cp15_reg (state, reg, opcode_2, CRm, value);
   
   return result;
 }
@@ -440,7 +441,7 @@ XScale_cp15_write_reg (ARMul_State * state ATTRIBUTE_UNUSED,
 {
   /* FIXME: Not sure what to do about the alternative register set
      here.  For now default to just accessing CRm == 0 registers.  */
-  write_cp15_reg (reg, 0, 0, value);
+  write_cp15_reg (state, reg, 0, 0, value);
   
   return TRUE;
 }
diff --git a/sim/arm/armdefs.h b/sim/arm/armdefs.h
index 204dc6bee3d..4ad5c5f07ae 100644
--- a/sim/arm/armdefs.h
+++ b/sim/arm/armdefs.h
@@ -317,10 +317,13 @@ extern void ARMul_Ccycles (ARMul_State * state, unsigned number,
 
 extern ARMword ARMul_ReadWord (ARMul_State * state, ARMword address);
 extern ARMword ARMul_ReadByte (ARMul_State * state, ARMword address);
+extern ARMword ARMul_SafeReadByte (ARMul_State * state, ARMword address);
 extern void ARMul_WriteWord (ARMul_State * state, ARMword address,
 			     ARMword data);
 extern void ARMul_WriteByte (ARMul_State * state, ARMword address,
 			     ARMword data);
+extern void ARMul_SafeWriteByte (ARMul_State * state, ARMword address,
+			     ARMword data);
 
 extern ARMword ARMul_MemAccess (ARMul_State * state, ARMword, ARMword,
 				ARMword, ARMword, ARMword, ARMword, ARMword,
diff --git a/sim/arm/armemu.c b/sim/arm/armemu.c
index 6b963c72c6f..dcc505fa3be 100644
--- a/sim/arm/armemu.c
+++ b/sim/arm/armemu.c
@@ -1369,8 +1369,8 @@ ARMul_Emulate26 (register ARMul_State * state)
 				  value |= 0xc;
 				  
 				  write_cp14_reg (10, value);
-				  write_cp15_reg (5, 0, 0, 0x200);  /* Set FSR.  */
-				  write_cp15_reg (6, 0, 0, pc);     /* Set FAR.  */
+				  write_cp15_reg (state, 5, 0, 0, 0x200);  /* Set FSR.  */
+				  write_cp15_reg (state, 6, 0, 0, pc);     /* Set FAR.  */
 				}
 			      else
 				break;
diff --git a/sim/arm/armemu.h b/sim/arm/armemu.h
index 4d4406d2254..009e9c8771a 100644
--- a/sim/arm/armemu.h
+++ b/sim/arm/armemu.h
@@ -491,6 +491,6 @@ extern void     ARMul_CoProAttach (ARMul_State *, unsigned, ARMul_CPInits *, ARM
 				   ARMul_LDCs *, ARMul_STCs *, ARMul_MRCs *, ARMul_MCRs *,
 				   ARMul_CDPs *, ARMul_CPReads *, ARMul_CPWrites *);
 extern void     ARMul_CoProDetach (ARMul_State *, unsigned);
-extern void     write_cp15_reg (unsigned, unsigned, unsigned, ARMword);
+extern void     write_cp15_reg (ARMul_State *, unsigned, unsigned, unsigned, ARMword);
 extern void     write_cp14_reg (unsigned, ARMword);
 extern ARMword  read_cp14_reg  (unsigned);
diff --git a/sim/arm/armos.c b/sim/arm/armos.c
index 678f177f5e1..93dcbd89345 100644
--- a/sim/arm/armos.c
+++ b/sim/arm/armos.c
@@ -139,9 +139,6 @@ 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
@@ -260,7 +257,7 @@ SWIWrite0 (ARMul_State * state, ARMword addr)
   ARMword temp;
   struct OSblock *OSptr = (struct OSblock *) state->OSptr;
 
-  while ((temp = ARMul_ReadByte (state, addr++)) != 0)
+  while ((temp = ARMul_SafeReadByte (state, addr++)) != 0)
     (void) fputc ((char) temp, stdout);
 
   OSptr->ErrorNo = errno;
@@ -277,7 +274,7 @@ WriteCommandLineTo (ARMul_State * state, ARMword addr)
   do
     {
       temp = (ARMword) * cptr++;
-      ARMul_WriteByte (state, addr++, temp);
+      ARMul_SafeWriteByte (state, addr++, temp);
     }
   while (temp != 0);
 }
@@ -290,7 +287,7 @@ SWIopen (ARMul_State * state, ARMword name, ARMword SWIflags)
   int flags;
   int i;
 
-  for (i = 0; (dummy[i] = ARMul_ReadByte (state, name + i)); i++)
+  for (i = 0; (dummy[i] = ARMul_SafeReadByte (state, name + i)); i++)
     ;
 
   /* Now we need to decode the Demon open mode.  */
@@ -329,7 +326,7 @@ SWIread (ARMul_State * state, ARMword f, ARMword ptr, ARMword len)
   res = read (f, local, len);
   if (res > 0)
     for (i = 0; i < res; i++)
-      ARMul_WriteByte (state, ptr + i, local[i]);
+      ARMul_SafeWriteByte (state, ptr + i, local[i]);
 
   free (local);
   state->Reg[0] = res == -1 ? -1 : len - res;
@@ -352,7 +349,7 @@ SWIwrite (ARMul_State * state, ARMword f, ARMword ptr, ARMword len)
     }
 
   for (i = 0; i < len; i++)
-    local[i] = ARMul_ReadByte (state, ptr + i);
+    local[i] = ARMul_SafeReadByte (state, ptr + i);
 
   res = write (f, local, len);
   state->Reg[0] = res == -1 ? -1 : len - res;
@@ -393,8 +390,6 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
   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)
@@ -516,7 +511,6 @@ 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:
@@ -539,7 +533,7 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
 	  break;
 
 	case AngelSWI_Reason_WriteC:
-	  (void) fputc ((int) ARMul_ReadByte (state, addr), stdout);
+	  (void) fputc ((int) ARMul_SafeReadByte (state, addr), stdout);
 	  OSptr->ErrorNo = errno;
 	  /* Fall thgrough.  */
 
@@ -633,8 +627,6 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
       break;
       
     default:
-      in_SWI_handler = 0;
-
       /* If there is a SWI vector installed use it.  */
       if (state->is_XScale && saved_number != -1)
 	number = saved_number;
@@ -665,7 +657,6 @@ ARMul_OSHandleSWI (ARMul_State * state, ARMword number)
 	}
     }
 
-  in_SWI_handler = 0;
   return TRUE;
 }
 
@@ -682,11 +673,7 @@ ARMul_OSException (ARMul_State * state  ATTRIBUTE_UNUSED,
 		   ARMword       vector ATTRIBUTE_UNUSED,
 		   ARMword       pc     ATTRIBUTE_UNUSED)
 {
-  /* 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;
+  return FALSE;
 }
 
 #endif
diff --git a/sim/arm/armvirt.c b/sim/arm/armvirt.c
index b9a018b997a..cca6aa0a415 100644
--- a/sim/arm/armvirt.c
+++ b/sim/arm/armvirt.c
@@ -24,6 +24,7 @@ freed as they might be needed again. A single area of memory may be
 defined to generate aborts. */
 
 #include "armopts.h"
+#include "armos.h"
 #include "armdefs.h"
 #include "ansidecl.h"
 
@@ -56,7 +57,7 @@ int SWI_vector_installed = FALSE;
 \***************************************************************************/
 
 static ARMword
-GetWord (ARMul_State * state, ARMword address)
+GetWord (ARMul_State * state, ARMword address, int check)
 {
   ARMword page;
   ARMword offset;
@@ -89,7 +90,7 @@ GetWord (ARMul_State * state, ARMword address)
 \***************************************************************************/
 
 static void
-PutWord (ARMul_State * state, ARMword address, ARMword data)
+PutWord (ARMul_State * state, ARMword address, ARMword data, int check)
 {
   ARMword page;
   ARMword offset;
@@ -191,8 +192,8 @@ ARMul_ReLoadInstr (ARMul_State * state, ARMword address, ARMword isize)
   if ((isize == 2) && (address & 0x2))
     {
       /* We return the next two halfwords: */
-      ARMword lo = GetWord (state, address);
-      ARMword hi = GetWord (state, address + 4);
+      ARMword lo = GetWord (state, address, TRUE);
+      ARMword hi = GetWord (state, address + 4, TRUE);
 
       if (state->bigendSig == HIGH)
 	return (lo << 16) | (hi >> 16);
@@ -200,7 +201,7 @@ ARMul_ReLoadInstr (ARMul_State * state, ARMword address, ARMword isize)
 	return ((hi & 0xFFFF) << 16) | (lo >> 16);
     }
 
-  return GetWord (state, address);
+  return GetWord (state, address, TRUE);
 }
 
 /***************************************************************************\
@@ -250,7 +251,7 @@ ARMword ARMul_ReadWord (ARMul_State * state, ARMword address)
     }
 #endif
 
-  return GetWord (state, address);
+  return GetWord (state, address, TRUE);
 }
 
 /***************************************************************************\
@@ -335,7 +336,7 @@ ARMul_WriteWord (ARMul_State * state, ARMword address, ARMword data)
     }
 #endif
 
-  PutWord (state, address, data);
+  PutWord (state, address, data, TRUE);
 }
 
 /***************************************************************************\
@@ -388,7 +389,8 @@ ARMul_StoreHalfWord (ARMul_State * state, ARMword address, ARMword data)
   offset = (((ARMword) state->bigendSig * 2) ^ (address & 2)) << 3;	/* bit offset into the word */
 
   PutWord (state, address,
-	   (temp & ~(0xffffL << offset)) | ((data & 0xffffL) << offset));
+	   (temp & ~(0xffffL << offset)) | ((data & 0xffffL) << offset),
+	   TRUE);
 }
 
 /***************************************************************************\
@@ -404,7 +406,8 @@ ARMul_WriteByte (ARMul_State * state, ARMword address, ARMword data)
   offset = (((ARMword) state->bigendSig * 3) ^ (address & 3)) << 3;	/* bit offset into the word */
 
   PutWord (state, address,
-	   (temp & ~(0xffL << offset)) | ((data & 0xffL) << offset));
+	   (temp & ~(0xffL << offset)) | ((data & 0xffL) << offset),
+	   TRUE);
 }
 
 /***************************************************************************\
@@ -444,7 +447,7 @@ ARMword ARMul_SwapWord (ARMul_State * state, ARMword address, ARMword data)
 
   state->NumNcycles++;
 
-  PutWord (state, address, data);
+  PutWord (state, address, data, TRUE);
 
   return temp;
 }
@@ -484,3 +487,30 @@ ARMul_Ccycles (ARMul_State * state, unsigned number, ARMword address ATTRIBUTE_U
   state->NumCcycles += number;
   ARMul_CLEARABORT;
 }
+
+
+/* Read a byte.  Do not check for alignment or access errors.  */
+
+ARMword
+ARMul_SafeReadByte (ARMul_State * state, ARMword address)
+{
+  ARMword temp, offset;
+
+  temp = GetWord (state, address, FALSE);
+  offset = (((ARMword) state->bigendSig * 3) ^ (address & 3)) << 3;
+
+  return (temp >> offset & 0xffL);
+}
+
+void
+ARMul_SafeWriteByte (ARMul_State * state, ARMword address, ARMword data)
+{
+  ARMword temp, offset;
+
+  temp = GetWord (state, address, FALSE);
+  offset = (((ARMword) state->bigendSig * 3) ^ (address & 3)) << 3;
+
+  PutWord (state, address,
+	   (temp & ~(0xffL << offset)) | ((data & 0xffL) << offset),
+	   FALSE);
+}
diff --git a/sim/arm/wrapper.c b/sim/arm/wrapper.c
index 242f0bbe2d2..877f7fbfd6f 100644
--- a/sim/arm/wrapper.c
+++ b/sim/arm/wrapper.c
@@ -1,5 +1,5 @@
 /* run front end support for arm
-   Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1997, 2000, 2001 Free Software Foundation, Inc.
 
 This file is part of ARM SIM.
 
@@ -126,7 +126,7 @@ sim_write (sd, addr, buffer, size)
   init ();
 
   for (i = 0; i < size; i++)
-    ARMul_WriteByte (state, addr + i, buffer[i]);
+    ARMul_SafeWriteByte (state, addr + i, buffer[i]);
 
   return size;
 }
@@ -139,11 +139,11 @@ sim_read (sd, addr, buffer, size)
      int size;
 {
   int i;
+
   init ();
   for (i = 0; i < size; i++)
-    {
-      buffer[i] = ARMul_ReadByte (state, addr + i);
-    }
+    buffer[i] = ARMul_SafeReadByte (state, addr + i);
+
   return size;
 }