This adds a XenIoMmioLib declaration and implementation that can
be invoked to install the XENIO_PROTOCOL and a corresponding
grant table address on a EFI handle.
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16979 6f19259b-4bc3-4df7-8a09-765794883524
On non-PCI Xen guests (such as ARM), the XenBus root is not a PCI
device but an abstract 'platform' device. Add a dedicated Vendor
Hardware device path GUID to identify this node.
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16978 6f19259b-4bc3-4df7-8a09-765794883524
This introduces the abstract XENIO_PROTOCOL that will be used to
communicate the Xen grant table address to drivers supporting this
protocol. Primary purpose is allowing us to change the XenBusDxe
implementation so that it can support non-PCI Xen implementations
such as Xen on ARM.
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16971 6f19259b-4bc3-4df7-8a09-765794883524
This moves all of the Xen hypercall code that was private to XenBusDxe
to a new library class XenHypercallLib. This will allow us to reimplement
it for ARM, and to export the Xen hypercall functionality to other parts
of the code, such as a Xen console SerialPortLib driver.
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16970 6f19259b-4bc3-4df7-8a09-765794883524
The TranslateMmioOfwNodes() function recognizes the following OpenFirmware
device paths:
virtio-blk: /virtio-mmio@000000000a003c00/disk@0,0
virtio-scsi disk: /virtio-mmio@000000000a003a00/channel@0/disk@2,3
virtio-net NIC: /virtio-mmio@000000000a003e00/ethernet-phy@0
The new translation can be enabled with the
"PcdQemuBootOrderMmioTranslation" Feature PCD. This PCD also controls if
the "survival policy" covers unselected boot options that start with the
virtio-mmio VenHw() node.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16575 6f19259b-4bc3-4df7-8a09-765794883524
Soon there will be more than one modules (in separate packages) that need
to have an understanding about the GUID used in the VenHw() device path
nodes that describe virtio-mmio transports. Define such a GUID explicitly.
Preserve the current value (which happens to be the FILE_GUID of
ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf) for
compatibility with external users.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16572 6f19259b-4bc3-4df7-8a09-765794883524
In preparation for adding OpenFirmware-to-UEFI translation for "MMIO-like"
OFW device path fragments, let's turn the currently exclusive "PCI-like"
translation into "just one" of the possible translations.
- Rename TranslateOfwNodes() to TranslatePciOfwNodes(), because it is
tightly coupled to "PCI-like" translations.
- Rename REQUIRED_OFW_NODES to REQUIRED_PCI_OFW_NODES, because this macro
is specific to TranslatePciOfwNodes().
- Introduce a new wrapper function under the original TranslateOfwNodes()
name. This function is supposed to try translations in some order until
a specific translation returns a status different from
RETURN_UNSUPPORTED.
- Introduce a new Feature PCD that controls whether PCI translation is
attempted at all.
- The boot option "survival policy" in BootOrderComplete() must take into
account if the user was able to select PCI-like boot options. If the
user had no such possibility (because the Feature PCD was off for
PCI-like translation), then we ought to keep any such unselected boot
options.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16571 6f19259b-4bc3-4df7-8a09-765794883524
and rebase OvmfPkg's PlatformBdsLib on the standalone library.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16570 6f19259b-4bc3-4df7-8a09-765794883524
Set from PEI, this PCD allows subsequent stages (specifically
DXE_DRIVER and DXE_RUNTIME_DRIVER) to infer the underlying platform
type (e.g. PIIX4 or Q35/MCH) without the need to further query the
Host Bridge for its Device ID.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16374 6f19259b-4bc3-4df7-8a09-765794883524
This protocol will be used for communication between a PV driver (like a
PV block driver) and the XenBus/XenStore.
Change in V5:
- Replace the license by the commonly used file header text.
Change in V3:
- Add disclaimer about the volatile nature of the protocol.
- Add a description on the two introduced members to the protocol.
Change in V2:
- Comment, file header
- Protocol License
- Declare xen interface version earlier
- Rename protocol from Xenbus to XenBus
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16262 6f19259b-4bc3-4df7-8a09-765794883524
OVMF's SecMain is unique in the sense that it links against the following
two libraries *in combination*:
- IntelFrameworkModulePkg/Library/LzmaCustomDecompressLib/
LzmaCustomDecompressLib.inf
- MdePkg/Library/BaseExtractGuidedSectionLib/
BaseExtractGuidedSectionLib.inf
The ExtractGuidedSectionLib library class allows decompressor modules to
register themselves (keyed by GUID) with it, and it allows clients to
decompress file sections with a registered decompressor module that
matches the section's GUID.
BaseExtractGuidedSectionLib is a library instance (of type BASE) for this
library class. It has no constructor function.
LzmaCustomDecompressLib is a compatible decompressor module (of type
BASE). Its section type GUID is
gLzmaCustomDecompressGuid == EE4E5898-3914-4259-9D6E-DC7BD79403CF
When OVMF's SecMain module starts, the LzmaCustomDecompressLib constructor
function is executed, which registers its LZMA decompressor with the above
GUID, by calling into BaseExtractGuidedSectionLib:
LzmaDecompressLibConstructor() [GuidedSectionExtraction.c]
ExtractGuidedSectionRegisterHandlers() [BaseExtractGuidedSectionLib.c]
GetExtractGuidedSectionHandlerInfo()
PcdGet64 (PcdGuidedExtractHandlerTableAddress) -- NOTE THIS
Later, during a normal (non-S3) boot, SecMain utilizes this decompressor
to get information about, and to decompress, sections of the OVMF firmware
image:
SecCoreStartupWithStack() [OvmfPkg/Sec/SecMain.c]
SecStartupPhase2()
FindAndReportEntryPoints()
FindPeiCoreImageBase()
DecompressMemFvs()
ExtractGuidedSectionGetInfo() [BaseExtractGuidedSectionLib.c]
ExtractGuidedSectionDecode() [BaseExtractGuidedSectionLib.c]
Notably, only the extraction depends on full-config-boot; the registration
of LzmaCustomDecompressLib occurs unconditionally in the SecMain EFI
binary, triggered by the library constructor function.
This is where the bug happens. BaseExtractGuidedSectionLib maintains the
table of GUIDed decompressors (section handlers) at a fixed memory
location; selected by PcdGuidedExtractHandlerTableAddress (declared in
MdePkg.dec). The default value of this PCD is 0x1000000 (16 MB).
This causes SecMain to corrupt guest OS memory during S3, leading to
random crashes. Compare the following two memory dumps, the first taken
right before suspending, the second taken right after resuming a RHEL-7
guest:
crash> rd -8 -p 1000000 0x50
1000000: c0 00 08 00 02 00 00 00 00 00 00 00 00 00 00 00 ................
1000010: d0 33 0c 00 00 c9 ff ff c0 10 00 01 00 88 ff ff .3..............
1000020: 0a 6d 57 32 0f 00 00 00 38 00 00 01 00 88 ff ff .mW2....8.......
1000030: 00 00 00 00 00 00 00 00 73 69 67 6e 61 6c 6d 6f ........signalmo
1000040: 64 75 6c 65 2e 73 6f 00 00 00 00 00 00 00 00 00 dule.so.........
vs.
crash> rd -8 -p 1000000 0x50
1000000: 45 47 53 49 01 00 00 00 20 00 00 01 00 00 00 00 EGSI.... .......
1000010: 20 01 00 01 00 00 00 00 a0 01 00 01 00 00 00 00 ...............
1000020: 98 58 4e ee 14 39 59 42 9d 6e dc 7b d7 94 03 cf .XN..9YB.n.{....
1000030: 00 00 00 00 00 00 00 00 73 69 67 6e 61 6c 6d 6f ........signalmo
1000040: 64 75 6c 65 2e 73 6f 00 00 00 00 00 00 00 00 00 dule.so.........
The "EGSI" signature corresponds to EXTRACT_HANDLER_INFO_SIGNATURE
declared in
MdePkg/Library/BaseExtractGuidedSectionLib/BaseExtractGuidedSectionLib.c.
Additionally, the gLzmaCustomDecompressGuid (quoted above) is visible at
guest-phys offset 0x1000020.
Fix the problem as follows:
- Carve out 4KB from the 36KB gap that we currently have between
PcdOvmfLockBoxStorageBase + PcdOvmfLockBoxStorageSize == 8220 KB
and
PcdOvmfSecPeiTempRamBase == 8256 KB.
- Point PcdGuidedExtractHandlerTableAddress to 8220 KB (0x00807000).
- Cover the area with an EfiACPIMemoryNVS type memalloc HOB, if S3 is
supported and we're not currently resuming.
The 4KB size that we pick is an upper estimate for
BaseExtractGuidedSectionLib's internal storage size. The latter is
calculated as follows (see GetExtractGuidedSectionHandlerInfo()):
sizeof(EXTRACT_GUIDED_SECTION_HANDLER_INFO) + // 32
PcdMaximumGuidedExtractHandler * (
sizeof(GUID) + // 16
sizeof(EXTRACT_GUIDED_SECTION_DECODE_HANDLER) + // 8
sizeof(EXTRACT_GUIDED_SECTION_GET_INFO_HANDLER) // 8
)
OVMF sets PcdMaximumGuidedExtractHandler to 16 decimal (which is the
MdePkg default too), yielding 32 + 16 * (16 + 8 + 8) == 544 bytes.
Regarding the lifecycle of the new area:
(a) when and how it is initialized after first boot of the VM
The library linked into SecMain finds that the area lacks the signature.
It initializes the signature, plus the rest of the structure. This is
independent of S3 support.
Consumption of the area is also limited to SEC (but consumption does
depend on full-config-boot).
(b) how it is protected from memory allocations during DXE
It is not, in the general case; and we don't need to. Nothing else links
against BaseExtractGuidedSectionLib; it's OK if DXE overwrites the area.
(c) how it is protected from the OS
When S3 is enabled, we cover it with AcpiNVS in InitializeRamRegions().
When S3 is not supported, the range is not protected.
(d) how it is accessed on the S3 resume path
Examined by the library linked into SecMain. Registrations update the
table in-place (based on GUID matches).
(e) how it is accessed on the warm reset path
If S3 is enabled, then the OS won't damage the table (due to (c)), hence
see (d).
If S3 is unsupported, then the OS may or may not overwrite the
signature. (It likely will.) This is identical to the pre-patch status.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15433 6f19259b-4bc3-4df7-8a09-765794883524
This GUID should become a new "namespace" for UEFI variables that are
specific to OVMF configuration (as opposed to standard UEFI global
variables). We'll also use it as the GUID of the related HII form-set (ie.
the interactive user interface).
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15363 6f19259b-4bc3-4df7-8a09-765794883524
The S3 suspend/resume infrastructure depends on the LockBox library class.
The edk2 tree currently contains Null and SMM instances. The Null instance
is useless, and the SMM instance would require SMM emulation by including
the SMM core and adding several new drivers, which is deemed too complex.
Hence add a simple LockBoxLib instance for OVMF.
jordan.l.justen@intel.com:
* use PCDs instead of EmuNvramLib
- clear memory in PlatformPei on non S3 boots
* allocate NVS memory and store a pointer to that memory
- reduces memory use at fixed locations
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15301 6f19259b-4bc3-4df7-8a09-765794883524
This 32k section of RAM will be declared to the PEI Core on
S3 resume to allow memory allocations during S3 resume PEI.
If the boot mode is BOOT_ON_S3_RESUME, then we publish
the pre-reserved PcdS3AcpiReservedMemory range to PEI.
If the boot mode is not BOOT_ON_S3_RESUME, then we reserve
this range as ACPI NVS so the OS will not use it.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15294 6f19259b-4bc3-4df7-8a09-765794883524
By splitting the PEI and DXE phases into separate FVs,
we can only reserve the PEI FV for ACPI S3 support.
This should save about 7MB.
Unfortunately, this all has to happen in a single commit.
DEC:
* Remove PcdOvmfMemFv(Base|Size)
* Add PcdOvmfPeiMemFv(Base|Size)
* Add PcdOvmfDxeMemFv(Base|Size)
FDF:
* Add new PEIFV. Move PEI modules here.
* Remove MAINFV
* Add PEIFV and DXEFV into FVMAIN_COMPACT
- They are added as 2 sections of a file, and compressed
together so they should retain good compression
* PcdOvmf(Pei|Dxe)MemFv(Base|Size) are set
SEC:
* Find both the PEI and DXE FVs after decompression.
- Copy them separately to their memory locations.
Platform PEI driver:
* Fv.c: Publish both FVs as appropriate
* MemDetect.c: PcdOvmfMemFv(Base|Size) =>
PcdOvmfDxeMemFv(Base|Size)
OVMF.fd before:
Non-volatile data storage
FVMAIN_COMPACT uncompressed
FV FFS file LZMA compressed
MAINFV uncompressed
individual PEI modules uncompressed
FV FFS file compressed with PI_NONE
DXEFV uncompressed
individual DXE modules uncompressed
SECFV uncompressed
OVMF.fd after:
Non-volatile data storage
FVMAIN_COMPACT uncompressed
FV FFS file LZMA compressed
PEIFV uncompressed
individual PEI modules uncompressed
DXEFV uncompressed
individual DXE modules uncompressed
SECFV uncompressed
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15151 6f19259b-4bc3-4df7-8a09-765794883524
Note: The Temporary RAM memory size is being reduced from
64KB to 32KB. This still appears to be more than
adequate for OVMF's early PEI phase. We will be adding
another 32KB range of RAM just above this range for
use on S3 resume.
The range is declared as part of MEMFD, so it is easier
to identify the memory range.
We also now assign PCDs to the memory range.
The PCDs are used to set the initial SEC/PEI stack in
SEC's assembly code.
The PCDs are also used in the SEC C code to setup
the Temporary RAM PPI.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15147 6f19259b-4bc3-4df7-8a09-765794883524
To help consolidate OVMF fixed memory uses, we declare this
range in MEMFD and thereby move it to 8MB.
We also now declare the table range in the FDF to set
PCDs. This allows us to ASSERT that CR3 is set as expected
in OVMF SEC.
OvmfPkgIa32.fdf and OvmfPkgIa32X64.fdf are updated simply
for consistency.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15146 6f19259b-4bc3-4df7-8a09-765794883524
This protocol introduces an abstraction to access the VirtIo
Configuration and Device spaces.
The registers in these spaces are located at a different offset and have
a different width whether the transport layer is either PCI or MMIO. This
protocol would also allow to support VirtIo PCI devices with MSI-X
capability in a transparent way (Device space is at a different offset
when a PCIe device has MSI-X capability).
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
v5:
- add disclaimer (two instances) about the protocol being work in progress
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14963 6f19259b-4bc3-4df7-8a09-765794883524
PcdFlashNvStorageVariableBase64 is used to arbitrate between
QemuFlashFvbServicesRuntimeDxe and EmuVariableFvbRuntimeDxe, but even the
latter driver sets it if we fall back to it.
Allow code running later than the startup of these drivers to know about
the availability of flash variables, through a dedicated PCD.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14843 6f19259b-4bc3-4df7-8a09-765794883524
This patch adds support for a debug console on the same port that is used
by SeaBIOS. This makes it easier to debug OVMF, because it does not mix
debug and serial output on the same device. It also makes it easier to
leave some of the debug messages on even in release builds.
To enable it, pass "-debugcon stdio -global isa-debugcon.iobase=0x402" to
QEMU.
The new mechanism is enabled by default, but a regular serial console can
be chosen by adding -D DEBUG_ON_SERIAL_PORT to the build options.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
[jordan.l.justen@intel.com: MAX_DEBUG_MESSAGE_LENGTH=>0x100, p=>Ptr]
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13562 6f19259b-4bc3-4df7-8a09-765794883524
XenInfo HOB is used to pass XenInfo from PEI to DXE.
Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Reviewed-by: gavinguan
Reviewed-by: jljusten
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12059 6f19259b-4bc3-4df7-8a09-765794883524
1) Remove section header comment blocks that do not provide any information
2) Combine PCDs listed in multiple sections into a single section that supports multiple PCD types to reduce maintenance overhead
3) Remove ModuleTypeList comments from [Includes], [Protocols], [Ppis], and [Guids] sections that do not properly describe the module type restrictions.
4) Clean up formatting of GUID structure declarations
5) Remove ".common" from section names if they are not required.
6) Order sections consistently as [Defines], [Includes], [LibraryClasses], [Guid], [Ppis], [Protocols], [PcdsFeatureFlag], [PcdsFixedAtBuild], [PcdsPatchableInModule], [PcdsDynamic], and [PcdsDynamicEx]
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11633 6f19259b-4bc3-4df7-8a09-765794883524
This library provides an interface for converting the system
variables into a binary and also restoring the system variables
from that binary.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11284 6f19259b-4bc3-4df7-8a09-765794883524
This protocol is similar to the standard UEFI BlockIo protocol,
except it has no function calls and simply defines a base address
in memory where reads & writes for the block device should occur.
One planned usage is to fill a memory region with a small disk
image, and allow it to be used as a normal disk by the
standard drivers.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10295 6f19259b-4bc3-4df7-8a09-765794883524
* Only SEC is uncompressed now
* The MAIN FV with PEI & DXE can easily shrink and grow as needed
* The final output will now be OVMF.Fv rather than OVMF.fd
* The final output size will be a multiple of 64kb
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9672 6f19259b-4bc3-4df7-8a09-765794883524
This library provides an interface where variables can be saved and restored
using a file in a file system accessible to the firmware. It is expected
that a platform BDS library will use this library. The platform BDS
implementation can decide which devices to connect and then to attempt to use
for saving and restoring NV variables.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9272 6f19259b-4bc3-4df7-8a09-765794883524