CloverBootloader/OvmfPkg/Library/QemuFwCfgS3Lib/QemuFwCfgS3Pei.c

81 lines
3.5 KiB
C

/** @file
Limited functionality QemuFwCfgS3Lib instance, for PEI phase modules.
QemuFwCfgS3Enabled() queries S3 enablement via fw_cfg. Other library APIs
will report lack of support.
Copyright (C) 2017, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/QemuFwCfgS3Lib.h>
/**
Install the client module's FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION callback for
when the production of ACPI S3 Boot Script opcodes becomes possible.
Take ownership of the client-provided Context, and pass it to the callback
function, when the latter is invoked.
Allocate scratch space for those ACPI S3 Boot Script opcodes to work upon
that the client will produce in the callback function.
@param[in] Callback FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION to invoke
when the production of ACPI S3 Boot Script
opcodes becomes possible. Callback() may be
called immediately from
QemuFwCfgS3CallWhenBootScriptReady().
@param[in,out] Context Client-provided data structure for the
Callback() callback function to consume.
If Context points to dynamically allocated
memory, then Callback() must release it.
If Context points to dynamically allocated
memory, and
QemuFwCfgS3CallWhenBootScriptReady() returns
successfully, then the caller of
QemuFwCfgS3CallWhenBootScriptReady() must
neither dereference nor even evaluate Context
any longer, as ownership of the referenced area
has been transferred to Callback().
@param[in] ScratchBufferSize The size of the scratch buffer that will hold,
in reserved memory, all client data read,
written, and checked by the ACPI S3 Boot Script
opcodes produced by Callback().
@retval RETURN_UNSUPPORTED The library instance does not support this
function.
@retval RETURN_NOT_FOUND The fw_cfg DMA interface to QEMU is
unavailable.
@retval RETURN_BAD_BUFFER_SIZE ScratchBufferSize is too large.
@retval RETURN_OUT_OF_RESOURCES Memory allocation failed.
@retval RETURN_SUCCESS Callback() has been installed, and the
ownership of Context has been transferred.
Reserved memory has been allocated for the
scratch buffer.
A successful invocation of
QemuFwCfgS3CallWhenBootScriptReady() cannot
be rolled back.
@return Error codes from underlying functions.
**/
RETURN_STATUS
EFIAPI
QemuFwCfgS3CallWhenBootScriptReady (
IN FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION *Callback,
IN OUT VOID *Context OPTIONAL,
IN UINTN ScratchBufferSize
)
{
return RETURN_UNSUPPORTED;
}