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Configuration Profiles (BIOS Flavors) Implementation

Table of Contents

Description

This document describes the requirements, design considerations and APIs for UEFI Configuration Profiles.

Revision History

Revised by Date Changes
Oliver Smith-Denny 09/15/2022 Initial design
Oliver Smith-Denny 02/27/2023 XML Spec Update
Oliver Smith-Denny 04/14/2023 Add XML Profiles

Terms

Term Description
UEFI Unified Extensible Firmware Interface
MFCI Manufacturer Firmware Configuration Interface
FV Firmware Volume

Reference Documents

Document Link
MFCI Documentation Link
SetupVariable Flow Link

Introduction

Configuration Profiles

UEFI Configuration Profiles, historically called BIOS Flavors, are sets of defined values for UEFI configuration variables. Such profiles are useful where different owners may use the same hardware but have different requirements for UEFI configuration variables, such as one owner requiring Secure Boot enabled and SMT disabled and another owner requiring Secure Boot disabled and SMT enabled. Configuration profiles are provided by the FW as a means to allow both groups to use the same hardware and FW, but choosing different profiles with the set of configuration they require.

Design

Flow

There will be one generic profile that describes the default values for all UEFI configuration variables. This generic profile will be generated during build time from one XML configuration file specified in PlatformBuild.py as MU_SCHEMA_DIR to the directory path and MU_SCHEMA_FILE_NAME as the XML filename. Additional profiles will be represented as change files (CSV files generated by the ConfigEditor UI tool) specified by CONF_PROFILE_PATHS as a space separated string of paths in PlatformBuild.py, e.g.:

self.env.SetValue('CONF_PROFILE_PATHS',
                            self.mws.join(self.ws, 'Platforms', 'PlatformPkg', 'Config', 'Profile1.csv'),
                            self.mws.join(self.ws, 'Platforms', 'PlatformPkg', 'Config', 'Profile2.csv')
)

If MU_SCHEMA_FILE_NAME has multiple entries (see Platform Integration Steps), then there may be a semicolon delimited list of CONF_PROFILE_PATHS. UpdateConfigHdr.py will match these in the same order as the schema files, i.e. CONF_PROFILE_PATHS first entry will be applied to the first entry of MU_SCHEMA_FILE_NAME. If there is no corresponding entry, it will be assumed there is no profile override to that schema file.

Platform owners can develop a configuration profile for their use case. Following examples and the format provided in the ConfigurationFiles doc, these owners can create an XML change file describing the set of configuration variables and their values that are in the profile that differ from the generic profile. The ConfigEditor UI tool may be used to assist in loading the XML and saving the output into change files, as well as manipulating the values as necessary.

The profiles will be used as overrides to the generic profile, to be published as the config policy. The profiles will define the entire set of UEFI configuration variables.

Platform owners will need to update their PlatformConfigDataLib to include <Generated/ConfigProfilesGenerated.h> after including the client and standard headers (for definitions). The profile data is contained within this header file to be consumed by the OEM/platform config policy creator.

Profile Update

Profiles will only be added and have values updated during build time.

If a new configuration knob is required to be added to the configuration profile, it must go into the generic profile with a default value in addition to whichever profiles choose to override it.

If a configuration knob is required to change to a new value with the same structure, it can simply be updated using the Config Editor UI tool to the new value.

If a new structure is required for an existing configuration knob, then it is required that a new configuration knob be added, with the old knob being removed as soon as feasible.

Active Profile Selection

The ActiveProfileIndexSelectorLib library class is intended to be overridden by the OEM/platform to retrieve the active profile index from the relevant source of truth. If ActiveProfileIndexSelectorLib has a failure fetching the active profile index, the OEM/platform has the choice of failing to boot, defaulting to the last used profile, or defaulting to the generic profile.

This index returned is an index into the gProfileData structure contained within <Generated/ConfigProfilesGenerated.h>. This will return a KNOB_OVERRIDE structure which is a set of overrides to knobs that can be iterated through and applied to the CacheValueAddress of each overridden knob.

Alternatively, if the generic profile is chosen, ActiveProfileIndexSelectorLib will return MAX_UINT32 to indicdate the gProfileData structure is not used for this boot and instead only the defaults in gKnobData (and possibly any overrides found in variable storage) will be used.

Platform Usage Recommendations

Generate Profile CSV Files

There are 2 ways to generate the CSV files:

  • Through ConfigEditor UI tool:

  • Load the XML configuration file

  • Make any changes

  • Save the CSV file by selecting the "Save Config Changes to Change File" button. Show below:

    Profile Through ConfigEditor UI tool

  • Through the command line:

  • Run GenNCCfgData.py script with specified XML file and output CSV file, for example:

    GenNCCfgData.py GENCSV sampleschema.xml;input.bin output.csv

Add Profile CSV Files to PlatformBuild.py

If platforms would like to integrate the profile CSV files into their build, they can add the following to their build by following the statements outlined in the section above.

Provide Profile Names and IDs

Platforms also can provide a 2-character name and/or 1-byte ID for each profile. These are used to identify the profile by the selector, which could be BMC, OS, or other.

In firmware, the name and ID are auto generated and can be accessed through gProfileFlavorNames and gProfileFlavorIds, respectively. Platforms can elect to create HOBs for this meta data information and consume it in other drivers. See example here.

To integrate the name and ID into the build, platforms can add the following to their build by following the statements:

self.env.SetValue('CONF_PROFILE_NAMES', "P2,P1", "Platform Hardcoded")
self.env.SetValue('CONF_PROFILE_IDS', "2,1", "Platform Hardcoded")

Note that the profile names and IDs are optional. If they are not provided, the selector will use the profile index as the default name and ID.