Re: EmulatorPkg Unix Host Segmentation fault.

["Ni, Ray" <ray.ni@Intel.com>]

Jordan,
 > Study the PeiCore migration logic a bit more, I found since PeiCore
 > knows the exact size of new stack in permanent memory, it migrates
 > old stack to the top of new stack.
 > But the migration logic in above C code (since it doesn't know the
 > size of new stack, CopySize is the size of temporary memory) may copy 
 > the old stack to the middle in new stack.

Maybe your new RamMigration2 PPI needs to carry both the old and new 
stack/heap location and size.
It helps:
1. migrate the old stack to top of new stack (instead of middle of new 
stack).
2. potentially reduce the size of memory that needs to be copied.

TemporaryRamMigration (
   IN CONST EFI_PEI_SERVICES             **PeiServices,
   IN EFI_PHYSICAL_ADDRESS               TemporaryStackBase,
   IN EFI_PHYSICAL_ADDRESS               PermanentStackSize,
   IN EFI_PHYSICAL_ADDRESS               TemporaryHeapBase,
   IN EFI_PHYSICAL_ADDRESS               PermanentHeapSize,
   IN TEMPORARY_RAM_MIGRATION_CALLBACK   Callback,
   IN VOID                               *Context
   )


Before the finalize of PI spec change regarding the RamMigration2 
change, I prefer to fix the EmulatorPkg boot crash ASAP using the
OVMF-like solution.
If you agree, I will send out the patch to let you review.

-- 
Thanks,
Ray