Companion Updater

Disk partitions:

• Boot - runs UBoot, The linux bootloader. This is configured to boot the companion installation first, and fall back to the recovery installation if companion fails to boot.
• Recovery - Recovery and update management installation. This (archlinux) installation runs a simple apache webserver with php. The webserver allows uploading a compressed companion installation image, stores it in the staging partition, then extracts it over the existing companion installation
• User (to be implemented) - User data for companion installation - This is for the user's files and configurations. This partition will not be affected during the recovery/update process, thus the user's files are persistent during updates.
• Staging (to be implemented) - filesystem to store compressed image to be burned
• Companion - filesystem to run the companion installation

./conf contains files to configure and run the webserver these files are located according where they should be installed (copied) on the root filesystem

./install contains scripts to install the system

Setup/Installation

1. create directories /mnt/boot and /mnt/root
2. select an sd card at least 8G in size
3. run sudo ./makearch.sh /dev/sdX to install everything on the disk (you might have to accept some proceed anyway requests during the filesystem creation)
4. put the sd card in the pi, connect it to a monitor and a keyboard (and your router if you want)
5. hold the spacebar down while the pi boots
6. at the uboot command line enter setenv brpart /dev/mmcblk0p2 or whatever partition you want to mount for root (this gets passed to the kernel as the root= option)
7. at the uboot command line enter run bootcmd
8. done!

more steps

4. more steps to come... (this can probably be done easier using chroot)
5. ssh to the pi user alarm password alarm or use root/root
6. move the initarch.sh from here to the pi
7. run the initarch.sh on the pi
8. Move files from conf here to / on the pi
9. reboot or systemctl restart httpd
10. visit pi ip address in browser to see webpage

problems

libarchive is installed forcefully and leaves behind root folders in the project

Reference

1. https://archlinuxarm.org/platforms/armv8/broadcom/raspberry-pi-3
2. http://randombio.com/linuxsetup107.html

Going further

Ways in which we may want to expand the funcionality provided here

1. uboot netconsole
2. watchdog
3. fallback support
4. network booting

Use this to back up an SD card

Create diskimage IMG of the disk DISK (eg. /dev/sdg careful!)

$ sudo bash ./copyarch.sh DISK IMG

#Things I've tried

$ p1 boot p2 arch p3 companion part results: companion part give error

/sbin/init does not exist
bailing out, you are on your own

p1 boot p2 arch p3 arch (UUIDS were the same) boot in p3: results: success!

remove uuid=3 from boot.txt results:

ERROR=device'PARTUUID=' not found. skipping fsck.

then i get logged into rootfs

sudo bash ./prepare-disk.sh /dev/sdh 2G 2G