What are the failsafe modes?

[mbo2o]

Set a tftp server on your PC

Download or build the appropriate initramfs image

From boot use the tftpboot command to fetch the initramfs image and boot it.

Note, what I called ramdisk image is refered to as initramfs image in the openwrt downloads.

Booting an initramfs image

I'd like to test an OpenWrt 19.07.0-rc2 image I've built for the GL.iNet GL-MV1000. I'd like to test it without potentially bricking the device by booting the initramfs image. So noob question, how do I do this? Can I upload it using the uboot web UI? If so will it then reboot to my image (in RAM) - and then after the next reboot go back to flash? Thanks.