[edk2-devel] [PATCH v3 2/6] OvmfPkg: Add QemuFwCfgLibNull
Laszlo Ersek
lersek at redhat.com
Thu Apr 23 08:21:53 UTC 2020
On 04/21/20 05:09, Rebecca Cran wrote:
> Add a null implementation library for QemuFwCfgLib, in order to
> support building PciHostBridgeLib for bhyve.
>
> Signed-off-by: Rebecca Cran <rebecca at bsdio.com>
> ---
> .../Library/QemuFwCfgLib/QemuFwCfgLibNull.inf | 37 ++++
> OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c | 209 ++++++++++++++++++
> 2 files changed, 246 insertions(+)
> create mode 100644 OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibNull.inf
> create mode 100644 OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c
>
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibNull.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibNull.inf
> new file mode 100644
> index 0000000000..09f86c2b02
> --- /dev/null
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibNull.inf
> @@ -0,0 +1,37 @@
> +## @file
> +#
> +# Stateful, implicitly initialized fw_cfg library.
(1) This comment should be updated -- it should say (for example):
"Null implementation of the fw_cfg library".
(I could update this for you myself, but below there is another change
that I cannot do for you.)
> +#
> +# Copyright (C) 2013, Red Hat, Inc.
> +# Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
> +# Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
(2) This is a new file; you should add your (C) on top (like you do in
patch#1). I can't add this for you.
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 0x00010005
> + BASE_NAME = QemuFwCfgLibNull
> + FILE_GUID = B9D1A1F2-01E2-4732-982D-C7F9ED51AC6B
> + MODULE_TYPE = BASE
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = QemuFwCfgLib
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#
> +# VALID_ARCHITECTURES = IA32 X64
> +#
(3) Technically speaking, the null instance is suitable for all
architectures supported by edk2. I suggest simply dropping the
VALID_ARCHITECTURES comment block.
> +
> +[Sources]
> + QemuFwCfgLibInternal.h
(4) We don't depend on this header file, please don't list it here.
> + QemuFwCfgNull.c
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + MdeModulePkg/MdeModulePkg.dec
(5) I *think* MdeModulePkg.dec is not needed, as we don't consume any
content from MdeModulePkg. (The DebugLib class comes from MdePkg.)
> + OvmfPkg/OvmfPkg.dec
Yes, this is necessary (because the lib class header that we'll include
comes from OvmfPkg).
> +
> +[LibraryClasses]
> + DebugLib
> diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c
> new file mode 100644
> index 0000000000..e2cc5f3406
> --- /dev/null
> +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgNull.c
> @@ -0,0 +1,209 @@
> +/** @file
> +
> + Stateful and implicitly initialized fw_cfg library implementation.
(6) Same as (1).
> +
> + Copyright (C) 2013, Red Hat, Inc.
> + Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
> + Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>
> +
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
(7) Same as (2).
> +
> +#include <Uefi.h>
> +#include <Library/DebugLib.h>
> +#include <IndustryStandard/QemuFwCfg.h>
> +
(8) I believe <Uefi.h> and <IndustryStandard/QemuFwCfg.h> can be dropped.
In exchange, <Library/QemuFwCfgLib.h> should be included. That's because
the lib class header declares the functions that this lib instance will
define (= implement). The lib class header also pulls in all
dependencies that are needed for the API declarations.
When you include <Library/QemuFwCfgLib.h>, please add it under
DebugLib.h, to keep the #include list sorted.
> +/**
> + Returns a boolean indicating if the firmware configuration interface
> + is available or not.
> +
> + This function may change fw_cfg state.
> +
> + @retval TRUE The interface is available
> + @retval FALSE The interface is not available
> +
> +**/
> +BOOLEAN
> +EFIAPI
> +QemuFwCfgIsAvailable (
> + VOID
> + )
> +{
> + return FALSE;
> +}
> +
> +
> +/**
> + Selects a firmware configuration item for reading.
> +
> + Following this call, any data read from this item will start from
> + the beginning of the configuration item's data.
> +
> + @param[in] QemuFwCfgItem - Firmware Configuration item to read
> +
> +**/
> +VOID
> +EFIAPI
> +QemuFwCfgSelectItem (
> + IN FIRMWARE_CONFIG_ITEM QemuFwCfgItem
> + )
> +{
> + ASSERT (FALSE);
> +}
> +
> +
> +/**
> + Reads firmware configuration bytes into a buffer
> +
> + If called multiple times, then the data read will
> + continue at the offset of the firmware configuration
> + item where the previous read ended.
> +
> + @param[in] Size - Size in bytes to read
> + @param[in] Buffer - Buffer to store data into
> +
> +**/
> +VOID
> +EFIAPI
> +QemuFwCfgReadBytes (
> + IN UINTN Size,
> + IN VOID *Buffer OPTIONAL
> + )
> +{
> + ASSERT (FALSE);
> +}
> +
> +
> +/**
> + Writes firmware configuration bytes from a buffer
> +
> + If called multiple times, then the data written will
> + continue at the offset of the firmware configuration
> + item where the previous write ended.
> +
> + @param[in] Size - Size in bytes to write
> + @param[in] Buffer - Buffer to read data from
> +
> +**/
> +VOID
> +EFIAPI
> +QemuFwCfgWriteBytes (
> + IN UINTN Size,
> + IN VOID *Buffer
> + )
> +{
> + ASSERT (FALSE);
> +}
> +
> +
> +/**
> + Skip bytes in the firmware configuration item.
> +
> + Increase the offset of the firmware configuration item without transferring
> + bytes between the item and a caller-provided buffer. Subsequent read, write
> + or skip operations will commence at the increased offset.
> +
> + @param[in] Size Number of bytes to skip.
> +**/
> +VOID
> +EFIAPI
> +QemuFwCfgSkipBytes (
> + IN UINTN Size
> + )
> +{
> + ASSERT (FALSE);
> +}
> +
> +
> +/**
> + Reads a UINT8 firmware configuration value
> +
> + @return Value of Firmware Configuration item read
> +
> +**/
> +UINT8
> +EFIAPI
> +QemuFwCfgRead8 (
> + VOID
> + )
> +{
> + ASSERT (FALSE);
> + return 0;
> +}
> +
> +
> +/**
> + Reads a UINT16 firmware configuration value
> +
> + @return Value of Firmware Configuration item read
> +
> +**/
> +UINT16
> +EFIAPI
> +QemuFwCfgRead16 (
> + VOID
> + )
> +{
> + ASSERT (FALSE);
> + return 0;
> +}
> +
> +
> +/**
> + Reads a UINT32 firmware configuration value
> +
> + @return Value of Firmware Configuration item read
> +
> +**/
> +UINT32
> +EFIAPI
> +QemuFwCfgRead32 (
> + VOID
> + )
> +{
> + ASSERT (FALSE);
> + return 0;
> +}
> +
> +
> +/**
> + Reads a UINT64 firmware configuration value
> +
> + @return Value of Firmware Configuration item read
> +
> +**/
> +UINT64
> +EFIAPI
> +QemuFwCfgRead64 (
> + VOID
> + )
> +{
> + ASSERT (FALSE);
> + return 0;
> +}
> +
> +
> +/**
> + Find the configuration item corresponding to the firmware configuration file.
> +
> + @param[in] Name - Name of file to look up.
> + @param[out] Item - Configuration item corresponding to the file, to be passed
> + to QemuFwCfgSelectItem ().
> + @param[out] Size - Number of bytes in the file.
> +
> + @return RETURN_SUCCESS If file is found.
> + RETURN_NOT_FOUND If file is not found.
> + RETURN_UNSUPPORTED If firmware configuration is unavailable.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +QemuFwCfgFindFile (
> + IN CONST CHAR8 *Name,
> + OUT FIRMWARE_CONFIG_ITEM *Item,
> + OUT UINTN *Size
> + )
> +{
> + return RETURN_UNSUPPORTED;
> +}
> +
>
These parts are fine.
Thanks!
Laszlo
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