mirror of https://github.com/acidanthera/audk.git
97 lines
2.5 KiB
C
97 lines
2.5 KiB
C
/** @file
|
|
|
|
Stateless fw_cfg library implementation.
|
|
|
|
Clients must call QemuFwCfgIsAvailable() first.
|
|
|
|
Copyright (C) 2013, Red Hat, Inc.
|
|
Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
|
|
|
|
This program and the accompanying materials are licensed and made available
|
|
under the terms and conditions of the BSD License which accompanies this
|
|
distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
|
|
WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
**/
|
|
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/QemuFwCfgLib.h>
|
|
|
|
#include "QemuFwCfgLibInternal.h"
|
|
|
|
/**
|
|
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
|
|
)
|
|
{
|
|
UINT32 Signature;
|
|
UINT32 Revision;
|
|
|
|
QemuFwCfgSelectItem (QemuFwCfgItemSignature);
|
|
Signature = QemuFwCfgRead32 ();
|
|
DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));
|
|
QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
|
|
Revision = QemuFwCfgRead32 ();
|
|
DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));
|
|
if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||
|
|
(Revision < 1)
|
|
) {
|
|
DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));
|
|
return FALSE;
|
|
}
|
|
|
|
DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));
|
|
return TRUE;
|
|
}
|
|
|
|
|
|
/**
|
|
Returns a boolean indicating if the firmware configuration interface is
|
|
available for library-internal purposes.
|
|
|
|
This function never changes fw_cfg state.
|
|
|
|
@retval TRUE The interface is available internally.
|
|
@retval FALSE The interface is not available internally.
|
|
**/
|
|
BOOLEAN
|
|
InternalQemuFwCfgIsAvailable (
|
|
VOID
|
|
)
|
|
{
|
|
//
|
|
// We always return TRUE, because the consumer of this library ought to have
|
|
// called QemuFwCfgIsAvailable before making other calls which would hit this
|
|
// path.
|
|
//
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
Returns a boolean indicating whether QEMU provides the DMA-like access method
|
|
for fw_cfg.
|
|
|
|
@retval TRUE The DMA-like access method is available.
|
|
@retval FALSE The DMA-like access method is unavailable.
|
|
**/
|
|
BOOLEAN
|
|
InternalQemuFwCfgDmaIsAvailable (
|
|
VOID
|
|
)
|
|
{
|
|
return FALSE;
|
|
}
|