hmm... no. that doesnt sound right.
Fastboot should prevent the usb thingy.
and also... why not do something less radical than flash
sudo fastboot getvar bootmode
just check you are connected and everything is sane before you go off writing stuff in an "unknown state"... Kinda dangerous no?
imx usb loader with a gui
Hmm I kinda remember this thing. Yeah it worked fine IIRC for me on ubuntu Mint.
why not have the usb connected. reboot the kindle (do your jkey sequence) and then try to connect. then do a sudo fasboot getvar bootmode
That's a plan, will establish connectivity, then try flash
if you get a response.