1 /** @file 2 Variable Architectural Protocol as defined in PI Specification VOLUME 2 DXE 3 4 This provides the services required to get and set environment variables. This 5 protocol must be produced by a runtime DXE driver and may be consumed only by 6 the DXE Foundation. The DXE driver that produces this protocol must be a runtime 7 driver. This driver is responsible for initializing the GetVariable(), 8 GetNextVariableName(), and SetVariable() fields of the UEFI Runtime Services Table. 9 10 After the three fields of the UEFI Runtime Services Table have been initialized, 11 the driver must install the EFI_VARIABLE_ARCH_PROTOCOL_GUID on a new handle with 12 a NULL interface pointer. The installation of this protocol informs the DXE Foundation 13 that the read-only and the volatile environment variable related services are 14 now available and that the DXE Foundation must update the 32-bit CRC of the UEFI 15 Runtime Services Table. The full complement of environment variable services are 16 not available until both this protocol and EFI_VARIABLE_WRITE_ARCH_PROTOCOL are 17 installed. DXE drivers that require read-only access or read/write access to volatile 18 environment variables must have this architectural protocol in their dependency 19 expressions. DXE drivers that require write access to nonvolatile environment 20 variables must have the EFI_VARIABLE_WRITE_ARCH_PROTOCOL in their dependency 21 expressions. 22 23 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR> 24 SPDX-License-Identifier: BSD-2-Clause-Patent 25 26 **/ 27 28 #ifndef __ARCH_PROTOCOL_VARIABLE_ARCH_H__ 29 #define __ARCH_PROTOCOL_VARIABLE_ARCH_H__ 30 31 /// 32 /// Global ID for the Variable Architectural Protocol 33 /// 34 #define EFI_VARIABLE_ARCH_PROTOCOL_GUID \ 35 { 0x1e5668e2, 0x8481, 0x11d4, {0xbc, 0xf1, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81 } } 36 37 extern EFI_GUID gEfiVariableArchProtocolGuid; 38 39 #endif 40