U-Boot recovery for i.MX6 Q/D/DL/S/ULL via JTAG
Technically all JTAG-adapter listed by OpenOCD should work, but DH electronics recommends the Olimex Arm-USB-OCD-Tiny-H. All tests and Documents were made in use of this one.
Needed Hardware
- JTAG Debugger: Olimex Arm-USB-OCD-Tiny-H.
- DHCOM JTAG adapter for FFC connection: Article number FD00037
- Wuerth FFC cable: 687610050002
- Note: One cable is included with the DHCOM JTAG adapter.
Installation
This installation was made on the Virtual Machine for Application Development. All console expressions refer to this Debian system, but any other debian based system should also work.
OpenOCD from Debian repositories (i.MX6 Q/D/DL/S)
- Install OpenOCD from Debian repositories
sudo apt-get install openocd
OpenOCD from master branch (i.MX6 ULL)
- Install needed libraries and tools
sudo apt-get install git build-essential pkg-config autoconf automake libtool libusb-dev libusb-1.0-0-dev libhidapi-dev libftdi-dev
- Clone git repository to local directory
git clone https://repo.or.cz/openocd.git
- Prepare source directory and submodules (when building from the git repository)
./bootstrap
- Generate the Makefiles to build OpenOCD
./configure
- Build OpenOCD from source
make -j4
- Install OpenOCD to /usr/local
sudo make install
U-Boot Programing
There are two ways for doing this. The easy way is an automatic Bash-script, which handles all the commands needed for the programing process. In this case you need a specified folder-structure so that the automatic script can find all its needed files. The other one is to type in the required commands. In a few cases this fails then you need to go the other way and program the uBoot manually.
- Download the needed files here: Programing Files
- Here you get the "dhcom_olimex_arm_usb_tiny_h.cfg" and the "u-boot-spl-prog"
- Download newest uBoot here: uBoot_iMX6
- Here you get the "uBoot.imx"
- Connecting everything
- Connect the JTAG-Adapter with your PC and the Debian VM (Player - Removeable Devices)
- Connect the JTAG interface via the DHCOM JTAG adapter to the i.MX6 module (If you don't have a JTAG adapter, please ask DH electronics)
- Connect the board with a serial COM-port: Enter Bootloader Console
- Automatic Script
- Create a new folder (it isn't necessary where the folder is located, you just need to keep the folder structure)
- The needed folder structure looks like this:
- DHcom_uBoot_Programmer
- bin_File (here are the uBoot files)
- uBoot_Programmer (here are the Programing scripts)
- Paste the "dhcom_olimex_arm_usb_tiny_h.cfg"-file in the OpenOCD folder at
/usr/share/openocd/scripts/board
- The "uBoot_Programmer_Olimex_arm_usb_tiny_h.sh"-file needs to be in the uBoot_Programmer folder
- In the bin_Folder belongs the "u-boot-spl-prog.bin" and your own uBoot file
- You need to adjust the "uBoot_Programmer_Olimex_arm_usb_tiny_h.sh" in terms of the name of your uBoot-file. Paste the name instead of the term "Your uBoot File"
- DHcom_uBoot_Programmer
- Open a Linux terminal and navigate into the folder e.g.
cd DHcom_uBoot_Programmer/uBoot_Programmer
- Power up the i.MX6 board and have a look at the serial output (COM-port). There must not be any output (no uBoot starting) else go to Delete uBoot
- Start the programing script:
./uBoot_Programmer_Olimex_arm_usb_tiny_h.sh
- Note: If some error occures you can try the Manual Programing method below
- Manual Programming (Only needed if automatic script is not used!!!)
- Power up the board and have a look at the serial output. If there is any uBoot starting:Delete uBoot
- You need two terminals, one for GDB the other for OpenOCD an a Com-Port to get the serial output
- OpenOCD
openocd –f board/dhcom_olimex_arm_usb_tiny_h.cfg
- If OpenOCD does not open like in the picture then close and open it again
- GDB
- Open second terminal window
gdb --quiet
target remote localhost:3333
mon load_image /path/to/the/u-boot-spl-prog/file 0x908000
mon reg pc 0x908000
mon reset
mon resume
- Wait until the message "Searching for IVT header at DDR address 0x18000000" is on the serial output
mon halt
mon load_image /path/to/the/u-boot-with-spl/file 0x18000000
mon resume
Trouble shooting
If there is a U-Boot starting, the OpenOCD procedure may not work properly. There are two solutions to prevent the start of U-Boot from the SPI-NOR-Flash.
SDP Boot (i.MX6 ULL)
- Boot in Serial Download Mode to prevent booting the broken U-Boot from SPI-NOR-Flash
- Go on with your procedure
Delete U-Boot (i.MX6 Q/D/DL/S)
sf probe
sf erase 0 f0000
- Restart the board
- Go on with your procedure