VariableWrite.h File Reference

Macros
#define	EFI_VARIABLE_WRITE_ARCH_PROTOCOL_GUID   { 0x6441f818, 0x6362, 0x4e44, {0xb5, 0x70, 0x7d, 0xba, 0x31, 0xdd, 0x24, 0x53 } }

Variables
EFI_GUID	gEfiVariableWriteArchProtocolGuid

Detailed Description

Variable Write Architectural Protocol as defined in PI Specification VOLUME 2 DXE

This provides the services required to set nonvolatile environment variables. This protocol must be produced by a runtime DXE driver and may be consumed only by the DXE Foundation.

The DXE driver that produces this protocol must be a runtime driver. This driver may update the SetVariable() field of the UEFI Runtime Services Table.

After the UEFI Runtime Services Table has been initialized, the driver must install the EFI_VARIABLE_WRITE_ARCH_PROTOCOL_GUID on a new handle with a NULL interface pointer. The installation of this protocol informs the DXE Foundation that the write services for nonvolatile environment variables are now available and that the DXE Foundation must update the 32-bit CRC of the UEFI Runtime Services Table. The full complement of environment variable services are not available until both this protocol and EFI_VARIABLE_ARCH_PROTOCOL are installed. DXE drivers that require read-only access or read/write access to volatile environment variables must have the EFI_VARIABLE_WRITE_ARCH_PROTOCOL in their dependency expressions. DXE drivers that require write access to nonvolatile environment variables must have this architectural protocol in their dependency expressions.

Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Macro Definition Documentation

#define EFI_VARIABLE_WRITE_ARCH_PROTOCOL_GUID   { 0x6441f818, 0x6362, 0x4e44, {0xb5, 0x70, 0x7d, 0xba, 0x31, 0xdd, 0x24, 0x53 } }

Global ID for the Variable Write Architectural Protocol

Variable Documentation

EFI_GUID gEfiVariableWriteArchProtocolGuid