SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The USB boot mode is used to read the boot image from external USB host .
See Section 4.3.13, USB Boot Device Configuration and Section 4.4.7, USB Boot Parameter Table for the available configuration options.
More information about USB DFU protocol can be found at http://www.usb.org/developers/docs/devclass_docs/DFU_1.1.pdf.
After successful enumeration, the ROM Code will start reading from the external host as specified by the BOOTMODE pins. It will continue reading data from the memory and storing it in internal RAM until a complete image has been read. When the complete image has been read and found in good integrity, the ROM Code will branch to the address defined in the Boot Info field of the boot header.