How to install Kali Linux on a USB for the RaspberryPi?

Question

Boot stuck at "random: crng init done" while using balenaEtcher or Win32 Disk Imager to flash Kali onto a USB.

Device: Raspberry Pi 3B+
Image: kali-linux-2019.4-rpi3-nexmon.img.xz from offensive-security.com

Answer 1

Easy Fix:

• Update root in cmdline.txt to /dev/sda2 (the correct partition in your case) Eg: root=/dev/sda2

• Update /etc/fstab to update the partitions from /dev/mmcblk0p1 and /dev/mmcblk0p2 to your usb device partitions

Full guide to what worked for me to get Kali up and running from the USB drive:

• Make sure your pi board is USB bootable. Should work out of the box for 3B+ (https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md)
• Download the official image for your pi model from offensive-security.com
• Use balenaEtcher or win32DiskImager to flash the image onto a USB Pendrive/HDD
• If you try booting now you will be stuck at "random: crng init done"
• To fix this, open the cmdline.txt on the Pendrive from a PC and change root to /dev/sda2 or whichever partition is relevant to your device. You can do some guesswork but sda2 should work in most cases: root=/dev/sda2
• You should now be able to boot but you will get stuck with some scripts. Press Ctrl + D when you are prompted. Enter the password which by default should be 'toor' and now you should have access to the terminal
• Next, you'll have to modify /etc/fstab. For this change directory to /etc and vim fstab

It should look something like this:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults          0       0
/dev/mmcblk0p1  /boot           vfat    defaults          0       2
/dev/mmcblk0p2  /               ext4    defaults,noatime  0       1

And needs to be updated to something like this:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults          0       0
/dev/sda1       /boot           vfat    defaults          0       2
/dev/sda2       /               ext4    defaults,noatime  0       1

Note: we only change the path /dev/mmcblk0p1 to /dev/sda1 and likewise for the other depending on your device.

• Reboot and you should be good to go.