In this section, you will create the boot images to be loaded through a USB using the DFU utility. Device firmware upgrade (DFU) is intended to download and upload firmware to/from devices connected over USB. In this boot mode, the boot loader (FSBL) and the PMU firmware which are loaded by bootROM are copied to Zynq UltraScale+ on-chip memory (OCM) from the host machine USB port using the DFU utility. The size of the OCM (256 KB) limits the size of the boot image downloaded by bootROM in USB boot mode. Considering this, and subject to the size requirement being met, only FSBL and PMU firmware are stitched into the first boot.bin, which is copied to the OCM. The remaining boot partitions will be stitched in another boot image and copied to DDR to be loaded by the FSBL which is already loaded and running at this stage. Follow these steps to create boot images for this boot mode.
In the Vitis IDE, select Vitis → Create Boot Image.
Select
fsbl_usb_boot.elfandpmufw.elfpartitions and set them as shown in the following figure.Ensure that the PMU partition is set to be loaded by bootROM.
Click Create Image to generate
BOOT.bin.