I'm trying to root my KF 6.3 following this article. http://forum.xda-developers.com/showthread.php?t=1568340&page=1
Now I'm in Kindle Fire screen (fastboot mode) but fastboot is missing.
hieund@hieund:~/Downloads/KF/RestoreRootFor6.3$ fastboot -i 0x1949 flash bootloader u-boot.bin fastboot: command not found
I am on Ubuntu 12.04 and have adb installed.