Send a firmware image

After invoking the bootloader, a menu is sent out the UART at 115200 baud. To upload a firmware image through the UART interface:

Look for the bootloader prompt BL > to ensure the bootloader is active.
Send an ASCII 1 character to initiate a firmware update.
After sending a 1, the device waits for an XModem CRC upload of a .gbl image over the serial line at 115200 baud. Send the .gbl file to the device using standard XMODEM-CRC.

If the firmware image is successfully loaded, the bootloader outputs a “complete” string. Invoke the newly loaded firmware by sending a 2 to the device.

If the firmware image is not successfully loaded, the bootloader outputs an "aborted string". It returns to the main bootloader menu. Some causes for failure are:

Over 1 minute passes after the command to send the firmware image and the first block of the image has not yet been sent.
A power cycle or reset event occurs during the firmware load.
A file error or a flash error occurs during the firmware load. The following table contains errors that could occur during the XMODEM transfer.

Error	Cause	Workaround
0x18	This error is observed when a serial upload attempt has been abruptly discontinued by invoking Ctrl+C and subsequently another attempt is made to upload a gbl by pressing 1 on the bootloader menu.	Press 2 on the bootloader menu. The bootloader performs a reboot and the menu gets displayed again. Now press 1 and begin uploading the gbl.