Imx uuu

Booting from USB using UUU utility

Introduction

UUU is an open source utility by NXP that allows downloading and executing code on NXP i.MX6/i.MX7/i.MX8 SoCs through the Serial Download Protocol (SDP).
It is the next generation of NXP's MFGTOOL used to load SPL and U-Boot via the USB OTG port and optionally program the internal storage of the SOM.
For more details please visit https://github.com/NXPmicro/mfgtools

Note:
All Variscite SOMs are shipped with U-Boot pre-programmed on the internal storage.
In addition, all Variscite carrier boards have an SD card slot, and even in the unlikely event of the U-Boot being erased from the internal storage, the SOM can always be booted from an SD card (like our recovery SD card, for example).
This utility can be used to program full software image to internal storage when SD and network boot options are not available.

Step by step usage instructions

Download and build the UUU utility:

$ sudo apt-get install libusb-1.0-0-dev libzip-dev libbz2-dev pkg-config cmake
$ cd ~
$ git clone https://github.com/NXPmicro/mfgtools.git
$ cd mfgtools
$ cmake .
$ make

Build U-Boot:

• Build U-Boot using the defconfig for SD card/eMMC. You can follow the "Build U-Boot from source code" instructions here.
  
• Copy the U-Boot image to uuu directory:

$ cp -v imx-boot-sd.bin ~/mfgtools/uuu
$ cd ~/mfgtools/uuu 
$ ln -fs imx-boot-sd.bin _flash.bin

Boot the board into serial download mode:

• Set the board boot mode to SD card, while not having an actual card inserted in its slot.
  
• Alternatively, set the board boot mode to eMMC/NAND flash, when the eMMC/NAND flash does not contain a bootloader.
  
• Connect the board to your host PC via the USB OTG port, and power on the board.
  
• Make sure the board is recognized on the host by running lsusb command and looking for the following output:

Bus 001 Device 021: ID 1fc9:013e NXP Semiconductors

Note:
If your board only has a regular USB type-A connector and doesn't have a USB Micro-AB or Type-C receptacle, you can use a "male USB type-A to male USB type-A" cable

Run uuu to load U-Boot on the board:

 $ sudo ./uuu ./spl_boot.lst

The board should now run U-Boot.
You can see its output on the console via the debug port, as always.

Note:
The default boot command when booting from USB is bootcmd_mfg. It is defined in the board's default environment.
By default it runs fastboot but can be redefined or made empty.