UART Upgrade¶

UART upgrade is an empty-chip upgrade method. Through the PC tool UartBurn.exe, upgrade firmware is transmitted to the board. After the device enters U-Boot, firmware is flashed via U-Boot commands.

1. Tool Preparation¶

1.1 Obtain UartBurnTool¶

The UART upgrade tool is located at:

SDK/Tools/UartBurnTool/

2. Firmware Acquisition¶

UART upgrade requires the following firmware files:

IPL
TF_A
IPL_CUST
U-Boot

2.1 Compile to Generate Firmware¶

Execute the following command in the project directory to compile and generate firmware:

# Compile to generate all firmware
make image -j16

2.2 Firmware Location¶

After compilation, the firmware required for UART upgrade is located in the following directories:

Firmware	Location
IPL	`project/board/mhera/boot/uart/upgrade`
IPL_CUST	`project/board/mhera/boot/uart/upgrade`
TF_A	`project/board/mhera/boot/uart/upgrade/tf_a/`
U-Boot	`boot/`

2.3 Confirm Upgrade Process¶

Different chips may have different startup processes, which can be confirmed by checking the nor/nand boot log.

For example, the mhera process is: IPL -> TFA -> IPL_CUST -> U-Boot

Please import images in sequence according to the actual startup process.

Note:

U-Boot firmware must use xz compression format, not sz compression format

3. Switch Boot Mode¶

Select UART boot mode by changing the jumpers.

4. Upgrade Steps¶

4.1 Open UART Upgrade Tool¶

Note: UartBurn software will occupy the serial port, please close xshell or Flash Tool connections first.

Enter the UartBurnTool/ directory
Double-click to run UartBurn.exe

4.2 Select Serial Port and Connect¶

Select the corresponding COM port
Click the "Connect" button

4.3 Import Image¶

After Connect is successful, click the "Transfer" button to select firmware files for transmission in sequence.

4.4 Enter U-Boot¶

After U-Boot transmission is complete, the device will automatically enter the U-Boot command line interface.

Entering the U-Boot command line indicates the UART upgrade process was successful. Then use U-Boot commands to flash the firmware to flash.

5. Firmware Flashing¶

After entering the U-Boot command line, use the following commands for firmware flashing:

5.1 Upgrade via Ethernet¶

# estar

5.2 Upgrade via USB Drive¶

# usbstar

5.3 Upgrade via SD Card¶

# sdstar

After the upgrade is complete, the device will automatically reboot. At this point, switch the dial back to the flash boot mode corresponding to the firmware.