Skip to content

Latest commit

 

History

History
122 lines (85 loc) · 6.4 KB

add_new_attribute.md

File metadata and controls

122 lines (85 loc) · 6.4 KB
Raw

Add a new attribute

The power system device tree will maintain two types of attributes (HWP's (Hardware Procedure) and Non-HWP's attribute) for each target based on needs to init and boot POWER server. So, Please refer respective sub-section for steps.

  • To add hwp (hardware procedure) attribute, please refer here.

  • To add non-hwp attribute, please refer here.

  • To preserve the attribute value, please refer here.

Note: The steps will point to many files and a few will be POWER10 specific so, please refer and update the respective files based on your requirement if you are looking for another POWER processor version.

HWP's Attribute:

The attribute which is consumed by pub-ekb hardware procedure to init hardware units are called the hwp attribute.

  1. If the required new attribute defined in any of existing pub-ekb hwp's attributes xml's list then just adding that new attribute name into attribute filter list is sufficient. So, Please refer format for hwp attribute in attribute filter list to add i.e. prefix should be FA: along with attribute name (e.g. FA:ATTR_NAME).

    E.g.: FA:ATTR_NAME in new line.

    Tips to check:

    # Clone pub-ekb repository
git clone https://github.com/open-power/pub-ekb/

cd pub-ekb

# Checkout required branch i.e. git checkout branch_name

find . -name "*.xml" | xargs grep -l "<id>ATTR_CP_REFCLOCK_SELECT"
O/P:  ./chips/p10/procedures/xml/attribute_info/p10_clock_attributes.xml

# Just check above xml file path is present in hwp's attributes XML's list

  2. If the xml file path is not present in hwp's attributes xml's list then follow below steps.

    1. Add the xml file path in hwp's attributes xml's list to consider required attributes xml files from given pub-ekb repo path during build time.

    2. Add the xml file path into EKB_HWP_ATTRS_XML_FILES variable which is present in op-build ekb package to install required attributes xml files into staging directory instead of all files to consume by pdata for add new attribute into power system device tree during op-build.

    3. Add the xml file path into the REQ_ATTRS_XMLS variable which is present in openbmc ekb recipe to install required attributes xml files into staging directory instead of all files to consume by pdata for add new attribute into metadata files (attributes_info.H and attributes_info.db) during openbmc build.

    4. Add the attribute name into attribute filter list to get only required attributes from hwp's attributes xml file. Please refer format in attribute filter list to add i.e. prefix should be FA: along with attribute name (e.g. FA:ATTR_NAME).

  3. If the default value of attribute wants to change into the platform specific then follow below steps.

    1. Add the HWP attribute with default value in the custom ekb attributes file.

    E.g.:

        <attribute>
        <id>ATTR_NAME</id>
        <default>value</default>
    </attribute>

    Note: The attribute must be defined in any of the pub-ekb attributes xml files.

  4. To preserve the attribute value, please refer here.

Non-HWP's Attribute:

The attribute which is consumed by the platform (openBMC apps and openPOWER Hostboot) to init and boot the POWER server is called a non-hwp attribute.

  1. Add attribute definition (information about the type and other fields) based on needs in attributes definition xml file.

    Note: attribute definition should be in MRW format. Please refer here.

  2. Add attribute information for required target based on needs in target definition xml file.

    1. If the target is already present then add attribute information alone in xml as like other attributes (default value also can give).

    2. If the required attribute is want to add to more than one target then add attribute information into all require targets. Targets attributes are added based on inheritance approach (each target will have parent tag) so, adding attribute into parent target will apply to all its child targets.

    3. If the target is not present then add it as a new target (please refer to the format of the existing target definition in xml file). Also, please check whether that target is present in the required files by looking here.

  3. Add the attribute name into attribute filter list to get only required attributes from attributes xml file. Please refer format in attribute filter list to add i.e. prefix should be CA: along with attribute name (e.g. CA:ATTR_NAME).

  4. To preserve the attribute value, please refer here.

Preserve Attribute:

The service processor platform may be need to preserve the device tree attributes value in the different scenarios based on the needs.

  1. Add the attribute name in the preserved attributes list if wants to preserve during the service package update (aka, code update).

  2. Add the attribute name in the reinit attributes list if wants to reinit the attribute value during the cold boot based on the previous boot attribute value.