Yes!
From the quoted directions:
put your phone into flashing mode
The phone needs to be in serial download mode (aka flashing mode). That is the mode that allows uuu to be used.
If you succeed in getting your phone into serial download mode and connecting to your host computer via USB then lsusb on the host computer will show the phone as:
Bus 999 Device 999: ID 1fc9:012b NXP Semiconductors i.MX 8M Dual/8M QuadLite/8M Quad Serial Downloader
(where the bus number and device number won’t match the above and will be whatever is appropriate for where you connected the phone to on your host computer).
If you see Serial Downloader then you are good to go. If you don’t then you didn’t quite do it correctly.
I am copying in here the procedure for getting the phone into serial download mode from https://developer.puri.sm/Librem5/Development_Environment/Phone/Troubleshooting/Reflashing_the_Phone.html
- Ensure that the phone is switched off.
- Turn all Hardware-Kill-Switches off
- Remove battery
- Hold volume-up
- Insert the USB-c cable: (red light blinks, no green light)
- Reinsert the battery: (red light is constantly on, the script will continue)
- Release volume-up
NB: Don’t follow the rest of the instructions from that web page since you don’t actually want to reflash your phone!