/** @file\r
This file declares SMM Base abstraction protocol.\r
- This is the base level of compatiblity for SMM drivers.\r
-\r
+ This protocol is used to install SMM handlers for support of subsequent SMI/PMI activations. This\r
+ protocol is available on both IA-32 and Itanium®-based systems.\r
+ \r
+ The EFI_SMM_BASE_PROTOCOL is a set of services that is exported by a processor device. It is\r
+ a required protocol for the platform processor. This protocol can be used in both boot services and\r
+ runtime mode. However, only the following member functions need to exist into runtime:\r
+ - InSmm()\r
+ - Communicate()\r
+ This protocol is responsible for registering the handler services. The order in which the handlers are\r
+ executed is prescribed only with respect to the MakeLast flag in the RegisterCallback()\r
+ service. The driver exports these registration and unregistration services in boot services mode, but\r
+ the registered handlers will execute through the preboot and runtime. The only way to change the\r
+ behavior of a registered driver after ExitBootServices() has been invoked is to use some\r
+ private communication mechanism with the driver to order it to quiesce. This model permits typical\r
+ use cases, such as invoking the handler to enter ACPI mode, where the OS loader would make this\r
+ call before boot services are terminated. On the other hand, handlers for services such as chipset\r
+ workarounds for the century rollover in CMOS should provide commensurate services throughout\r
+ preboot and OS runtime.\r
+ \r
Copyright (c) 2007, Intel Corporation\r
All rights reserved. This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
projects / mirror_edk2.git / blobdiff