Primary Boot Device
The primary boot device is a QSPI device located on the SOM. The necessary elements are
packaged in a Zynq
®
Ult™ MPSoC specific format and file captured as
BOOT.BIN
. The
BOOT.BIN
file contains the board-specific boot firmware that consists of the following elements:
• FSBL: First-stage boot-loader firmware
• PMU: Platform management unit firmware
• ATF: Arm
®
trusted firmware
• U-Boot: Second-stage boot loader
U-Boot provides the functionality for the hand-off between the primary boot device and the
secondary boot device. It will search for both the SD card and eMMC secondary boot devices; if
both are detected it will provide a menu interface to you to select the desired Linux boot target.
The primary boot device provides a redundant copy of boot firmware arranged in an A/B
configuration. The A/B configuration provides a dynamic primary and secondary image operation
with corresponding update mechanisms. On boot, the system automatically boots from the
defined primary image, and, if boot fails, it falls back to the previously known good boot image.
Secondary Boot Device
The secondary boot device on the KV260 Starter Kit is the SD card. It contains the operating
system image and associated application files. The KV260 Starter Kit accelerated application
references are built on the Linux operating system. The
web page provides a pre-
built reference image that can be written to a microSD card for out-of-the-box functionality.
SOM board support packages (BSPs) are also available if you want to customize your OS.
RECOMMENDED: The SOM is designed to use SDHC standard microSD cards.
Chapter 3: Boot Devices and Firmware Overview
UG1089 (v1.2) July 26, 2022
KV260 Starter Kit
13
