OvmfPkg/PlatformInitLib: Add memory functions

Below functions are introduced in PlatformInitLib:
 - PlatformGetFirstNonAddress
 - PlatformAddressWidthInitialization
 - PlatformGetSystemMemorySizeBelow4gb
 - PlatformQemuUc32BaseInitialization
 - PlatformInitializeRamRegions

They correspond to the below functions in OvmfPkg/PlatformPei:
 - GetFirstNonAddress
 - AddressWidthInitialization
 - GetSystemMemorySizeBelow4gb
 - QemuUc32BaseInitialization
 - InitializeRamRegions

Note: PlatformInitLib will not determine whether SMM or S3 is supported
or not. Instead the caller of these functions should input SMM / S3
support as the IN parameter by themselves. This is to reduce the
complexity of PlatformInitLib. Another reason is that some PCDs cannot
be declared as FixedAtBuild while PlatformInitLib is designed to be used
in both SEC and PEI phase.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

OvmfPkg/Include/Library/PlatformInitLib.h

@@ -63,6 +63,84 @@ PlatformDebugDumpCmos (
   VOID
   );
 
+/**
+ * Return the highest address that DXE could possibly use, plus one.
+ *
+ * @param Pci64Base   The 64-bit PCI host aperture base address.
+ * @param Pci64Size   The 64-bit PCI host aperture size.
+ * @param DefaultPciMmio64Size  The default 64-bit PCI host aperture size.
+ *
+ * @return  The highest address that DXE could possibly use, plus one.
+ */
+UINT64
+EFIAPI
+PlatformGetFirstNonAddress (
+  OUT UINT64  *Pci64Base,
+  OUT UINT64  *Pci64Size,
+  IN  UINT64  DefaultPciMmio64Size
+  );
+
+/**
+ * Initialize the PhysMemAddressWidth variable, based on guest RAM size.
+ *
+ * @param   FirstNonAddress   The highest address that DXE could possibly use, plus one.
+ *
+ * @return  The physical memory address width based on the guest RAM size.
+ */
+UINT8
+EFIAPI
+PlatformAddressWidthInitialization (
+  IN UINT64  FirstNonAddress
+  );
+
+/**
+ * Get the memory size below 4GB.
+ *
+ * @return UINT32 The lower memory size.
+ */
+UINT32
+EFIAPI
+PlatformGetSystemMemorySizeBelow4gb (
+  VOID
+  );
+
+/**
+ * Initializatoin of Qemu UC32Base.
+ *
+ * @param HostBridgeDevId   The host bridge Dev Id.
+ * @param LowerMemorySize   The lower memory size (under 4G).
+ * @return UINT32   The Qemu UC32 base address.
+ */
+UINT32
+EFIAPI
+PlatformQemuUc32BaseInitialization (
+  IN UINT16  HostBridgeDevId,
+  IN UINT32  LowerMemorySize
+  );
+
+/**
+  Publish system RAM and reserve memory regions.
+
+  @param  Uc32Base
+  @param  HostBridgeDevId
+  @param  SmmSmramRequire
+  @param  BootMode
+  @param  S3Supported
+  @param  LowerMemorySize
+  @param  Q35TsegMbytes
+**/
+VOID
+EFIAPI
+PlatformInitializeRamRegions (
+  IN UINT32         Uc32Base,
+  IN UINT16         HostBridgeDevId,
+  IN BOOLEAN        SmmSmramRequire,
+  IN EFI_BOOT_MODE  BootMode,
+  IN BOOLEAN        S3Supported,
+  IN UINT32         LowerMemorySize,
+  IN UINT16         Q35TsegMbytes
+  );
+
 VOID
 EFIAPI
 PlatformAddIoMemoryBaseSizeHob (