Re: EmulatorPkg Unix Host Segmentation fault.

[Andrew Fish <afish@apple.com>]

> On Feb 15, 2019, at 11:40 PM, Ni, Ray <ray.ni@Intel.com <mailto:ray.ni@Intel.com>> wrote:
> 
> I also met this issue.
> I found three solutions:
> 1. Forcing PeiMain CC flag to "-O0" works.
> 2. Changing EmulatorPkg/Sec to not produce TemporaryRamSupportPpi also works.
> 3. Implement the temporary migration routine as below in EmulatorPkg/Sec module.
> 
> EFI_STATUS
> EFIAPI
> SecTemporaryRamSupport (
>  IN CONST EFI_PEI_SERVICES   **PeiServices,
>  IN EFI_PHYSICAL_ADDRESS     TemporaryMemoryBase,
>  IN EFI_PHYSICAL_ADDRESS     PermanentMemoryBase,
>  IN UINTN                    CopySize
>  )
> {
>  VOID                             *OldHeap;
>  VOID                             *NewHeap;
>  VOID                             *OldStack;
>  VOID                             *NewStack;
>  UINTN                            StackMigrateOffset;
>  BASE_LIBRARY_JUMP_BUFFER         JumpBuffer;
> 
>  DEBUG ((EFI_D_INFO,
>    "TemporaryRamMigration(0x%Lx, 0x%Lx, 0x%Lx)\n",
>    TemporaryMemoryBase,
>    PermanentMemoryBase,
>    (UINT64)CopySize
>    ));
> 
>  //
>  // Assume Host prepare the stack and heap in the temprary ram that stack
>  // is below heap (stack is in smaller address).
>  // Stack/heap migration depends on the stack/heap location information
>  // in the temporary ram.
>  //
>  OldStack = (VOID*)(UINTN)TemporaryMemoryBase;
>  NewStack = (VOID*)((UINTN)PermanentMemoryBase);
> 
>  OldHeap = (VOID*)((UINTN)TemporaryMemoryBase + (CopySize >> 1));
>  NewHeap = (VOID*)((UINTN)PermanentMemoryBase + (CopySize >> 1));
> 
>  StackMigrateOffset = (UINTN)NewStack - (UINTN)OldStack;
> 
>  //
>  // Migrate Heap and Stack
>  //
>  CopyMem (NewHeap, OldHeap, CopySize >> 1);
>  CopyMem (NewStack, OldStack, CopySize >> 1);
> 
>  //
>  // Use SetJump()/LongJump() to switch to a new stack.
>  //
>  if (SetJump (&JumpBuffer) == 0) {
> #if defined (MDE_CPU_IA32)
>    JumpBuffer.Esp = JumpBuffer.Esp + StackMigrateOffset;
>    JumpBuffer.Ebp = JumpBuffer.Ebp + StackMigrateOffset;
> #endif
> #if defined (MDE_CPU_X64)
>    JumpBuffer.Rsp = JumpBuffer.Rsp + StackMigrateOffset;
>    JumpBuffer.Rbp = JumpBuffer.Rbp + StackMigrateOffset;
> #endif
>    LongJump (&JumpBuffer, (UINTN)-1);
>  }
> 
>  ZeroMem ((VOID *)(UINTN) TemporaryMemoryBase, CopySize);
> 
>  return EFI_SUCCESS;
> }
> 
> 
> Andrew,
> I'd like to know why you chose to produce the migration PPI from
> EmulatorPkg/Sec module.
> Based on PI spec and current PeiCore implementation, PeiCore can do the migration when PPI is absent.
> 

Ray,

Sorry I don't remember if it was due to the code being so old, or if I was trying to better emulate a real platform.

Thanks,

Andrew Fish

> 
> 
> -- 
> Thanks,
> Ray
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