UefiCpuPkg: S3Resume2Pei: align return stacks	explicitly

S3RestoreConfig2() can optionally stack-switch to the SMM S3 Resume Entry
Point and ask it to transfer to S3ResumeExecuteBootScript().

Similarly, S3ResumeExecuteBootScript() stack-switches explicitly to the
boot script executor, and asks it to transfer to S3ResumeBootOs().

Currently the stack pointers specified for the SMM S3 Resume Entry Point
and the boot script executor to use for returning are derived from
addresses of the first local variables in S3RestoreConfig2() and
S3ResumeExecuteBootScript(), respectively.

Since (theoretically) the stack grows down as local variables are defined
and functions are called, the idea is presumably to allow the respective
callee to overwrite the caller's local variables. (The callees in
question can never return normally, only by explicit stack switching.)

Taking the address of "Status" is less portable than optimal however.
Compilers are free to juggle local variables at build time as they
please, including order and alignment on the stack. For example, when the
code is built for 64-bit PEI with gcc-4.8.2, the address of "Status"
trips up the alignment assertion in SwitchStack().

Let's align the address of "Status" down to CPU_STACK_ALIGNMENT
explicitly. If a compiler ensures such alignment and places "Status" at
the highest address automatically, then this change has no effect.
Otherwise, we'll prepare ReturnStackPointer values that (a) are correctly
aligned, (b) preserve the same amount or more (but never less) from the
caller's local variables than before, which should be safe.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed by: Jiewen Yao <Jiewen.Yao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14977 6f19259b-4bc3-4df7-8a09-765794883524
Fix meta file issue.

Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Hesheng Chen <hesheng.chen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14978 6f19259b-4bc3-4df7-8a09-765794883524
Check Context before use it.

Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14979 6f19259b-4bc3-4df7-8a09-765794883524
ArmPlatformPkg/ArmVExpressPkg: Added the empty 'ArmFvpDxe' platform UEFI driver

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>

v5:
- For uniformity, add the empty driver to
  ArmVExpress-RTSM-AEMv8Ax4-foundation.* too in this patch, not just
  ArmVExpress-RTSM-AEMv8Ax4.*. V4 added the empty driver to
  ArmVExpress-RTSM-AEMv8Ax4-foundation.* not sooner than the next patch,
  fusing it with other (= virtio) functionality. Let's split these changes
  cleanly.

Change-Id: I7d635011c8d3ac59097c728b7c7786d8677c80cb
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14980 6f19259b-4bc3-4df7-8a09-765794883524
ArmPlatformPkg/ArmFvpDxe: Added Virtio Block support

Right now the ARM Platform driver does not do much, but
I expect to move most platform specific code into platform
specific driver in the future.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>

v5:
- ensure / document that the VIRTIO_BLK_DEVICE_PATH structure must be
  packed
- fix whitespace damage in definition of "mVirtioBlockDevicePath"
- the platform driver is added to all platform DSC and FDF files in the
  previous patch; this patch focuses on virtio only

Change-Id: I3505bfc5b31085b8017bd9e6895a155bd7a2eee9
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14981 6f19259b-4bc3-4df7-8a09-765794883524
Merge branch 'master' of https://github.com/tianocore/edk2