in this approach we do not dump the image file onto the emmc but instead simply sync the contents of the running system onto newly created filesystems on the emmc. the advantages over legacy dd installation are:

- internet not required - no network connection required and the running system has everything required

- ability to preconfigure - the running image can already be a bit preconfigured and all changes to it will also be synced to emmc (maybe useful when installing on multiple identical systems)

- no uuid conflict - the filesystems on the emmc will get new filesystem uuids and also the labels of the filesystems can be easily adjusted, so no risk of a conflict with a booted rescue system from sd card/usb

Warning. if you don't want you system becoming unbootable in the future, before proceeding with installation it is recommended to first set gbb flags (you can't do this after the installation)

Remember. these steps have to be done from linux booted from usb, not chromeos

0. gaining root access

sudo -i

Note. password is same as for your user account

1. start by listing all available disks

lsblk

the output should look like this

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS mtdblock0 31:0 0 8M 0 disk sda 179:0 0 116,5G 0 disk <- this is the booted drive ├─sda1 179:1 0 64M 0 part <- this is a partition ├─sda2 179:2 0 64M 0 part ├─sda3 179:3 0 512M 0 part /boot ├─sda4 179:4 0 107,9G 0 part / <- it has current root partition └─sda5 179:5 0 8G 0 part mmcblk1 179:0 0 116,5G 0 disk <- this is an internal disk ├─mmcblk1p1 179:1 0 64M 0 part <- this is a partition ├─mmcblk1p2 179:2 0 64M 0 part ├─mmcblk1p3 179:3 0 512M 0 part ├─mmcblk1p4 179:4 0 107,9G 0 part └─mmcblk1p5 179:5 0 8G 0 part mmcblk1boot0 179:32 0 4M 1 disk mmcblk1boot1 179:64 0 4M 1 disk

Tip. the chromebook partition will be the one without partition with "/"

emmc disks can usually easily identified by the fact that there are also the following two (not to be used) devices for them as well: mmcblkxboot0, mmcblkxboot1

Note. the internal memory is often (but not always) mmcblk1 or mmcblk0 but don't be thrown off if it's something else

2. Export the target disk

if you want to install onto mmcblk0 or mmcblk1 (number is different on different chromebooks)

export disk=mmcblk0 export part=mmcblk0p

or

export disk=mmcblk1 export part=mmcblk1p

respecitively

if you want to install on sda or similar

export disk=sda export part=sda

3. Export the source disk

if the booted device is mmcblk0 or mmcblk1 (number is diffent on diffrent chromebooks)

export srcPart=mmcblk0p

or

export srcPart=mmcblk1p

respecitively

if the booted device is sda or similar

export srcPart=sda

4. Wipe the partition table on the target disk

sgdisk -Z /dev/$disk partprobe /dev/$disk sgdisk -C -e -G /dev/$disk partprobe /dev/$disk

5. Create a new partition table

cgpt create /dev/$disk

6. Create the two kernel partitions

cgpt add -i 1 -t kernel -b 8192 -s 65536 -l KernelA -S 1 -T 2 -P 10 /dev/$disk cgpt add -i 2 -t kernel -b 73728 -s 65536 -l KernelB -S 0 -T 2 -P 5 /dev/$disk

For veyron ONLY the following four lines should be used instead of the two above

cgpt add -i 1 -t kernel -b 73728 -s 32768 -l KernelA -S 1 -T 2 -P 10 /dev/$disk cgpt repair /dev/$disk cgpt add -i 2 -t kernel -b 106496 -s 32768 -l KernelB -S 0 -T 2 -P 5 /dev/$disk cgpt repair /dev/$disk

7. Create remaining partitions

wget https://raw.githubusercontent.com/hexdump0815/imagebuilder/main/systems/chromebook_veyron/gpt-partitions.txt

Note. but in theory all arm chromebooks should use the same setup here

fdisk /dev/$disk < gpt-partitions.txt

8. Create the boot and root filesystems and mount them

mkfs -t ext4 -O ^has_journal -m 0 -L bootemmc /dev/${part}3 mkfs -t btrfs -m single -L rootemmc /dev/${part}4 mount -o ssd,compress-force=zstd,noatime,nodiratime /dev/${part}4 /mnt mkdir -p /mnt/boot mount /dev/${part}3 /mnt/boot

Note: If deploying for the 3.10 kernel for the early Chromebook Snow releases, you must add `-O ^extref,^skinny-metadata,^no-holes,^zoned -R ^free-space-tree` to mkfs to disable features not supported by Linux 3.10. You also must omit `compress-force=zstd` when mounting.

9. copy the kernel partition to the target emmc

dd if=/dev/${srcPart}1 of=/dev/${part}1 bs=1024k status=progress

Note. the second kernel partition is by default unused initially

10. sync over the boot and root filesystems

rsync -axADHSX --no-inc-recursive --delete /boot/ /mnt/boot rsync -axADHSX --no-inc-recursive --delete --exclude='/swap/*' / /mnt

11. create a new 2gb swapfile (optional)

rm -rf /mnt/swap btrfs subvolume create /mnt/swap chmod 755 /mnt/swap chattr -R +C /mnt/swap btrfs property set /mnt/swap compression none cd /mnt/swap truncate -s 0 ./file.0; btrfs property set ./file.0 compression none; fallocate -l 2G file.0; chmod 600 ./file.0; mkswap -L file.0 ./file.0

Note. you can also create a swap partition

12. adjust the filesystem labels in the new etc/fstab

sed -i 's,bootpart,bootemmc,g;s,rootpart,rootemmc,g' /mnt/etc/fstab

13. do the same in the u-boot config file if it exists (on 32bit arm chromebooks only)

sed -i 's,rootpart,rootemmc,g' /mnt/boot/extlinux/extlinux.conf

14. umount everything

umount /mnt/boot /mnt

now after a shutdown the sd card/usb can be taken out/diconnected and the system should boot into linux from emmc on the next boot.

now after the system is installed onto memory you might want to tweak it a lil bit