Programmable Device Image - 2020.2 English

Versal ACAP System Software Developers Guide (UG1304)

Document ID
Release Date
2020.2 English

The boot image of Versal ACAP is called a PDI, which is a Xilinx file format processed by the PLM as part of the Versal ACAP boot process or partial configuration process. The PDI data is specific to the design requirements. The Versal ACAP boot image typically involves binaries used to boot and configure the platform, these binaries can include: bootloader, firmware, hardware configuration data, OS and user applications. Examples include Adaptable engine (PL) configuration file, PLM image, ATF, U-Boot, Linux kernels, rootfs, device tree, and standalone or RTOS applications.

A PDI file is a collection of images, where an image consists of one or more partitions. A partition can include:

  • CDO file consisting of a list of commands executed in sequence
  • Loadable data ( for example, APU/RPU ELFs or data)

There can be different PDI files based the use case.

PDI for Versal ACAP start-up
Occurs during the power-on reset (POR).

The PDI contains the following information needed to boot, configure, and manage Versal ACAP:

  • A boot header
  • A PLM
    Note: The PLM is read by the BootROM executable.
  • Additional subsystem images and image partitions used to configure a specific subsystem or engine.
  • Few of these images can also be part of another PDI targeted for secondary boot.
Subsystem Restart or DFX
Occurs in some power management, warm restart, and partial reconfiguration scenarios.

This type of PDI contains the information needed to reconfigure Versal ACAP, and does not contain the boot header and PLM.