if you have the UART port, you can set AT!MAPUART=16,1, and then after reboot, there will be linux console terminal in this UART port.
After that you can use the flash_eraseall command to erase the userapp partition.
if you have the UART port, you can set AT!MAPUART=16,1, and then after reboot, there will be linux console terminal in this UART port.
After that you can use the flash_eraseall command to erase the userapp partition.