Image Store - 2022.1 English

Versal ACAP System Software Developers Guide (UG1304)

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2022.1 English

The PLM supports storing of images in the DDR memory during boot time so that the images can be used later in cases like delay load, subsystem restart, and suspend/resume. This helps in reducing the load times because loading images from the DDR memory is faster than loading them from other boot devices. In bif of a Boot PDI, copy attribute can be used to specify the DDR memory address at which a particular image needs to be stored.

You can also create or upgrade the image store during run time by using partial PDIs. The address of the partial PDI loaded in the DDR memory can be passed to PLM using an IPI command and the PLM adds it into a PDI list. So, the PLM maintains a PDI list whose first entry is Boot PDI and rest of them are the PDI Addresses added during run time. During any of these use cases where a image has to be restarted, the PLM goes through the PDI list from the latest entry and checks if the required image is present in the PDI and loads it. If an image is not found or if the loading fails, the PLM performs a fallback to the next entry of the list until it reaches the Boot PDI.