ArmPkg,ArmPkg/ArmExceptionLib: drop vector relocation variant/support

There were several bugs in the vector table relocation code which means
it can't really have been used by anyone on AArch64 in the last decade or
so. So delete the support code from the library, as well as the
ArmRelocateExceptionLib.inf file.

This gets rid of PcdDebuggerExceptionSupport (including a duff reference
in CpuDxe), PcdCpuVectorBaseAddress and PcdRelocateVectorTable.

Signed-off-by: Leif Lindholm <leif.lindholm@oss.qualcomm.com>

9 files changed, 21 insertions, 252 deletions

diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
index 525a72015c..79d7cc2ff7 100644
--- a/ArmPkg/ArmPkg.dec
+++ b/ArmPkg/ArmPkg.dec
@@ -134,15 +134,6 @@
 [PcdsFeatureFlag.common]

   gArmTokenSpaceGuid.PcdCpuDxeProduceDebugSupport|FALSE|BOOLEAN|0x00000001

 

-  # On ARM Architecture with the Security Extension, the address for the

-  # Vector Table can be mapped anywhere in the memory map. It means we can

-  # point the Exception Vector Table to its location in CpuDxe.

-  # By default we copy the Vector Table at  PcdGet64(PcdCpuVectorBaseAddress)

-  gArmTokenSpaceGuid.PcdRelocateVectorTable|TRUE|BOOLEAN|0x00000022

-  # Set this PCD to TRUE if the Exception Vector is changed to add debugger support before

-  # it has been configured by the CPU DXE

-  gArmTokenSpaceGuid.PcdDebuggerExceptionSupport|FALSE|BOOLEAN|0x00000032

-

   # Whether to remap all unused memory NX before installing the CPU arch

   # protocol driver. This is needed on platforms that map all DRAM with RWX

   # attributes initially, and can be disabled otherwise.

@@ -161,7 +152,6 @@
   # Using a FeaturePcd make a '(BOOLEAN) casting for its value which is not understood by the preprocessor.

   gArmTokenSpaceGuid.PcdVFPEnabled|0|UINT32|0x00000024

 

-  gArmTokenSpaceGuid.PcdCpuVectorBaseAddress|0xffff0000|UINT64|0x00000004

   gArmTokenSpaceGuid.PcdCpuResetAddress|0x00000000|UINT32|0x00000005

 

   #

diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index b8817b4d7e..061d9d60dc 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -120,7 +120,6 @@
   ArmPkg/Library/SemiHostingSerialPortLib/SemiHostingSerialPortLib.inf

   ArmPkg/Library/SemihostLib/SemihostLib.inf

   ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.inf

-  ArmPkg/Library/ArmExceptionLib/ArmRelocateExceptionLib.inf

 

   ArmPkg/Drivers/CpuDxe/CpuDxe.inf

   ArmPkg/Drivers/CpuPei/CpuPei.inf

diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
index 1d6e2f99e1..deb4bad8d7 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
@@ -69,7 +69,6 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdDxeNxMemoryProtectionPolicy

 

 [FeaturePcd.common]

-  gArmTokenSpaceGuid.PcdDebuggerExceptionSupport

   gArmTokenSpaceGuid.PcdRemapUnusedMemoryNx

 

 [Depex]

diff --git a/ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c b/ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c
index b0c2e39cd9..1ae16ae3e4 100644
--- a/ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c
+++ b/ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c
@@ -14,11 +14,9 @@
 #include <Library/MemoryAllocationLib.h>

 #include <Protocol/DebugSupport.h> // for MAX_AARCH64_EXCEPTION

 

-UINTN                   gMaxExceptionNumber                                   = MAX_AARCH64_EXCEPTION;

-EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1]         = { 0 };

-EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };

-PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask                         = ARM_VECTOR_TABLE_ALIGNMENT;

-UINTN                   gDebuggerNoHandlerValue                               = 0; // todo: define for AArch64

+UINTN                   gMaxExceptionNumber                           = MAX_AARCH64_EXCEPTION;

+EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };

+PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask                 = ARM_VECTOR_TABLE_ALIGNMENT;

 

 #define EL0_STACK_SIZE  EFI_PAGES_TO_SIZE(2)

 STATIC UINTN  mNewStackBase[EL0_STACK_SIZE / sizeof (UINTN)];

diff --git a/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S b/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S
index 5dc6899773..714ead608f 100644
--- a/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S
+++ b/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S
@@ -109,12 +109,7 @@ GCC_ASM_EXPORT(CommonCExceptionHandler)
 // exception vector initialization method is used.

 //

 

-#if defined(ARM_RELOCATE_VECTORS)

-GCC_ASM_EXPORT(ExceptionHandlersStart)

-ASM_PFX(ExceptionHandlersStart):

-#else

 VECTOR_BASE(ExceptionHandlersStart)

-#endif

 

   .macro  ExceptionEntry, val, sp=SPx

   //

@@ -168,13 +163,7 @@ VECTOR_BASE(ExceptionHandlersStart)
   mov       x0, #\val

 

   // Jump to our general handler to deal with all the common parts and process the exception.

-#if defined(ARM_RELOCATE_VECTORS)

-  ldr       x1, =ASM_PFX(CommonExceptionEntry)

-  br        x1

-  .ltorg

-#else

   b         ASM_PFX(CommonExceptionEntry)

-#endif

   .endm

 

 //

diff --git a/ArmPkg/Library/ArmExceptionLib/Arm/ArmException.c b/ArmPkg/Library/ArmExceptionLib/Arm/ArmException.c
index 7652b97b43..ddff3e8f32 100644
--- a/ArmPkg/Library/ArmExceptionLib/Arm/ArmException.c
+++ b/ArmPkg/Library/ArmExceptionLib/Arm/ArmException.c
@@ -17,14 +17,9 @@
 

 #include <Protocol/DebugSupport.h> // for MAX_ARM_EXCEPTION

 

-UINTN                   gMaxExceptionNumber                               = MAX_ARM_EXCEPTION;

-EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1]         = { 0 };

-EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1] = { 0 };

-PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask                     = ARM_VECTOR_TABLE_ALIGNMENT;

-

-// Exception handler contains branch to vector location (jmp $) so no handler

-// NOTE: This code assumes vectors are ARM and not Thumb code

-UINTN  gDebuggerNoHandlerValue = 0xEAFFFFFE;

+UINTN                   gMaxExceptionNumber                       = MAX_ARM_EXCEPTION;

+EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1] = { 0 };

+PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask             = ARM_VECTOR_TABLE_ALIGNMENT;

 

 RETURN_STATUS

 ArchVectorConfig (

diff --git a/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c b/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c
index 03ed24794a..9832aba4b3 100644
--- a/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c
+++ b/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c
@@ -21,19 +21,6 @@
 #include <Library/DebugLib.h>

 #include <Library/DefaultExceptionHandlerLib.h>

 

-STATIC

-RETURN_STATUS

-CopyExceptionHandlers (

-  IN  PHYSICAL_ADDRESS  BaseAddress

-  );

-

-EFI_STATUS

-EFIAPI

-RegisterExceptionHandler (

-  IN EFI_EXCEPTION_TYPE         ExceptionType,

-  IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler

-  );

-

 VOID

 ExceptionHandlersStart (

   VOID

@@ -52,21 +39,7 @@ ArchVectorConfig (
 // these globals are provided by the architecture specific source (Arm or AArch64)

 extern UINTN                   gMaxExceptionNumber;

 extern EFI_EXCEPTION_CALLBACK  gExceptionHandlers[];

-extern EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[];

 extern PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask;

-extern UINTN                   gDebuggerNoHandlerValue;

-

-// A compiler flag adjusts the compilation of this library to a variant where

-// the vectors are relocated (copied) to another location versus using the

-// vectors in-place.  Since this effects an assembly .align directive we must

-// address this at library build time.  Since this affects the build of the

-// library we cannot represent this in a PCD since PCDs are evaluated on

-// a per-module basis.

-#if defined (ARM_RELOCATE_VECTORS)

-STATIC CONST BOOLEAN  gArmRelocateVectorTable = TRUE;

-#else

-STATIC CONST BOOLEAN  gArmRelocateVectorTable = FALSE;

-#endif

 

 /**

 Initializes all CPU exceptions entries and provides the default exception handlers.

@@ -90,107 +63,26 @@ InitializeCpuExceptionHandlers (
   IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL

   )

 {

-  RETURN_STATUS  Status;

-  UINT64         VectorBase;

-

-  Status = EFI_SUCCESS;

+  UINT64  VectorBase;

 

-  // if we are requested to copy exception handlers to another location

-  if (gArmRelocateVectorTable) {

-    VectorBase = PcdGet64 (PcdCpuVectorBaseAddress);

-    Status     = CopyExceptionHandlers (VectorBase);

-  } else {

-    // use VBAR to point to where our exception handlers are

+  // use VBAR to point to where our exception handlers are

 

-    // The vector table must be aligned for the architecture.  If this

-    // assertion fails ensure the appropriate FFS alignment is in effect,

-    // which can be accomplished by ensuring the proper Align=X statement

-    // in the platform packaging rules.  For ARM Align=32 is required and

-    // for AArch64 Align=4K is required.  Align=Auto can be used but this

-    // is known to cause an issue with populating the reset vector area

-    // for encapsulated FVs.

-    ASSERT (((UINTN)ExceptionHandlersStart & gExceptionVectorAlignmentMask) == 0);

+  // The vector table must be aligned for the architecture.  If this

+  // assertion fails ensure the appropriate FFS alignment is in effect,

+  // which can be accomplished by ensuring the proper Align=X statement

+  // in the platform packaging rules.  For ARM Align=32 is required and

+  // for AArch64 Align=4K is required.  Align=Auto can be used but this

+  // is known to cause an issue with populating the reset vector area

+  // for encapsulated FVs.

+  ASSERT (((UINTN)ExceptionHandlersStart & gExceptionVectorAlignmentMask) == 0);

 

-    // We do not copy the Exception Table at PcdGet64(PcdCpuVectorBaseAddress). We just set Vector

-    // Base Address to point into CpuDxe code.

-    VectorBase = (UINT64)(UINTN)ExceptionHandlersStart;

+  VectorBase = (UINT64)(UINTN)ExceptionHandlersStart;

 

-    Status = RETURN_SUCCESS;

-  }

+  // call the architecture-specific routine to prepare for the new vector

+  // configuration to take effect

+  ArchVectorConfig ((UINTN)VectorBase);

 

-  if (!RETURN_ERROR (Status)) {

-    // call the architecture-specific routine to prepare for the new vector

-    // configuration to take effect

-    ArchVectorConfig ((UINTN)VectorBase);

-

-    ArmWriteVBar ((UINTN)VectorBase);

-  }

-

-  return RETURN_SUCCESS;

-}

-

-/**

-Copies exception handlers to the specified address.

-

-Caller should try to get an array of interrupt and/or exception vectors that are in use and need to

-persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.

-If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.

-If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.

-

-@param[in]  VectorInfo    Pointer to reserved vector list.

-

-@retval EFI_SUCCESS           CPU Exception Entries have been successfully initialized

-with default exception handlers.

-@retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.

-@retval EFI_UNSUPPORTED       This function is not supported.

-

-**/

-STATIC

-RETURN_STATUS

-CopyExceptionHandlers (

-  IN  PHYSICAL_ADDRESS  BaseAddress

-  )

-{

-  RETURN_STATUS  Status;

-  UINTN          Length;

-  UINTN          Index;

-  UINT32         *VectorBase;

-

-  // ensure that the destination value specifies an address meeting the vector alignment requirements

-  ASSERT ((BaseAddress & gExceptionVectorAlignmentMask) == 0);

-

-  //

-  // Copy an implementation of the exception vectors to PcdCpuVectorBaseAddress.

-  //

-  Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;

-

-  VectorBase = (UINT32 *)(UINTN)BaseAddress;

-

-  if (FeaturePcdGet (PcdDebuggerExceptionSupport) == TRUE) {

-    // Save existing vector table, in case debugger is already hooked in

-    CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (EFI_EXCEPTION_CALLBACK)* (gMaxExceptionNumber+1));

-  }

-

-  // Copy our assembly code into the page that contains the exception vectors.

-  CopyMem ((VOID *)VectorBase, (VOID *)(UINTN)ExceptionHandlersStart, Length);

-

-  //

-  // Initialize the C entry points for interrupts

-  //

-  for (Index = 0; Index <= gMaxExceptionNumber; Index++) {

-    if (!FeaturePcdGet (PcdDebuggerExceptionSupport) ||

-        (gDebuggerExceptionHandlers[Index] == 0) || (gDebuggerExceptionHandlers[Index] == (VOID *)gDebuggerNoHandlerValue))

-    {

-      Status = RegisterExceptionHandler (Index, NULL);

-      ASSERT_EFI_ERROR (Status);

-    } else {

-      // If the debugger has already hooked put its vector back

-      VectorBase[Index] = (UINT32)(UINTN)gDebuggerExceptionHandlers[Index];

-    }

-  }

-

-  // Flush Caches since we updated executable stuff

-  InvalidateInstructionCacheRange ((VOID *)(UINTN)BaseAddress, Length);

+  ArmWriteVBar ((UINTN)VectorBase);

 

   return RETURN_SUCCESS;

 }

@@ -239,33 +131,6 @@ RegisterCpuInterruptHandler (
   return RETURN_SUCCESS;

 }

 

-/**

-Register exception handler.

-

-@param  This                  A pointer to the SMM_CPU_SERVICE_PROTOCOL instance.

-@param  ExceptionType         Defines which interrupt or exception to hook. Type EFI_EXCEPTION_TYPE and

-the valid values for this parameter are defined in EFI_DEBUG_SUPPORT_PROTOCOL

-of the UEFI 2.0 specification.

-@param  InterruptHandler      A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER

-that is called when a processor interrupt occurs.

-If this parameter is NULL, then the handler will be uninstalled.

-

-@retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.

-@retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was previously installed.

-@retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not previously installed.

-@retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.

-

-**/

-EFI_STATUS

-EFIAPI

-RegisterExceptionHandler (

-  IN EFI_EXCEPTION_TYPE         ExceptionType,

-  IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler

-  )

-{

-  return RegisterCpuInterruptHandler (ExceptionType, InterruptHandler);

-}

-

 VOID

 EFIAPI

 CommonCExceptionHandler (

diff --git a/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.inf b/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.inf
index 68ed1c5c59..611b49b99c 100644
--- a/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.inf
+++ b/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.inf
@@ -7,12 +7,6 @@
 # alignment must be propagated into the parent FFS/FV through FDF build rules

 # for the relevant module types (i.e. Align=Auto).

 #

-# Note that using this library instance can cause growth to the size of the FV

-# due to the padding added by the build tools to meet the vector alignment

-# requirements and may not be desirable for space-sensitive FVs (uncompressed /

-# XIP components).  The alternative library instance, ArmRelocateExceptionLib

-# should be considered for these applications.

-#

 #  Copyright (c) 2011-2012, ARM Limited. All rights reserved.

 #  Copyright (c) 2016 HP Development Company, L.P.

 #

@@ -53,5 +47,3 @@
   MemoryAllocationLib

 

 [Pcd]

-  gArmTokenSpaceGuid.PcdDebuggerExceptionSupport

-  gArmTokenSpaceGuid.PcdCpuVectorBaseAddress

diff --git a/ArmPkg/Library/ArmExceptionLib/ArmRelocateExceptionLib.inf b/ArmPkg/Library/ArmExceptionLib/ArmRelocateExceptionLib.inf
deleted file mode 100644
index ca70daa284..0000000000
--- a/ArmPkg/Library/ArmExceptionLib/ArmRelocateExceptionLib.inf
+++ /dev/null
@@ -1,58 +0,0 @@
-## @file

-# Instance of CpuExceptionHandlerLib Library for ARM/AArch64 architectures

-#

-# This library instance is used when exception vectors must be relocated to

-# a specific address.  The address is specified by PcdCpuVectorBaseAddress.

-# Since the alignment requirement for in-place exception handlers causes

-# image size to increase, this instance is useful for modules that need to

-# minimize space used in their FV (like XIP modules).  See ArmExceptionLib.inf

-# for the in-place exception handler alternative.

-#

-#  Copyright (c) 2011-2012, ARM Limited. All rights reserved.

-#  Copyright (c) 2016 HP Development Company, L.P.

-#

-#  SPDX-License-Identifier: BSD-2-Clause-Patent

-#

-#

-

-[Defines]

-  INF_VERSION                    = 0x00010005

-  BASE_NAME                      = ArmRelocateExceptionLib

-  FILE_GUID                      = 62AA447A-1FBA-429E-9E0D-CE0D2D8DCF58

-  MODULE_TYPE                    = BASE

-  VERSION_STRING                 = 1.0

-  LIBRARY_CLASS                  = CpuExceptionHandlerLib

-

-[Sources.common]

-  ArmExceptionLib.c

-

-[Sources.Arm]

-  Arm/ArmException.c

-  Arm/ExceptionSupport.S   | GCC

-

-[Sources.AARCH64]

-  AArch64/AArch64Exception.c

-  AArch64/ExceptionSupport.S

-

-[Packages]

-  MdePkg/MdePkg.dec

-  MdeModulePkg/MdeModulePkg.dec

-  ArmPkg/ArmPkg.dec

-

-[LibraryClasses]

-  ArmLib

-  DebugLib

-  DefaultExceptionHandlerLib

-  BaseMemoryLib

-  CacheMaintenanceLib

-

-[Pcd]

-  gArmTokenSpaceGuid.PcdDebuggerExceptionSupport

-  gArmTokenSpaceGuid.PcdCpuVectorBaseAddress

-

-[BuildOptions]

-  # We must pass a define to specify that we are relocating vectors so the

-  # vector alignment is relaxed (space savings); note that this must be done

-  # as a define and not a PCD since it affects assembly directives.

-  *_*_*_PP_FLAGS = -DARM_RELOCATE_VECTORS

-  *_*_*_CC_FLAGS = -DARM_RELOCATE_VECTORS