Dual booting Linux with ChromiumOS using "boot floppy"

[Wizzard]

Not really a guide, just want to share my findings with dual booting using SD card.

I have installed Ubuntu Linux and wanted to install Chromium OS on eMMC too.

So, download Chromium OS from ayufan's github: https://github.com/ayufan-rock64/chromiu...8d6.img.xz

Unzip it using unxz and write to SD card.

Code:

unxz chromiumos-rockpro64-R77-12371.7.104.g78f88d6.img.xz
sudo dd if=chromiumos-rockpro64-R77-12371.7.104.g78f88d6.img of=/dev/mmcblk0 bs=4M status=progress

Copy the partitions ROOT-A and STATE from SD card to eMMC in Gparted. If your Linux partition takes whole eMMC, first resize it when booted Linux from SD card.

Mount original ROOT-A partition on SD card and edit /boot/extlinux/extlinux.conf: replace "${bootdevice}p${bootdevice_part}" by the location of copied ROOT-A partition on your eMMC, in my case it was "mmcblk1p8".

Mount copied ROOT-A partition on your eMMC and edit /sbin/chromeos_startup: replace the line 212: STATE_DEV="${ROOTDEV_TYPE}${PARTITION_NUM_STATE}" by the partition number of your STATE partition on your eMMC, in my case it was 9, so my line is STATE_DEV="${ROOTDEV_TYPE}9"

That is all. Now you should be able to boot Chromium OS from eMMC using booting SD card or default Linux without SD card.

Similar way works for booting Recalbox from eMMC (confirmed).

[TDC_PBP]

Thank you for this AMAZING tutorial! I only have one problem: the default allocation for files in chromium OS is 1.95 GB.  I can expand the partition in Gparted while in Bionic Mate, but chromium doesn't recognize the added space.  I also can't put the download folder in a different location because even when I create a partition for it on the EMMC or the microSD card it doesn't recognize it. Please help!

[Wizzard]

That is really interesting, but I dont understand why it does not detect those space. I do not have CrOS installed now, but I remember that I could resize the CrOS partition on another PC and it worked, as far as I remember.

[TDC_PBP]

I have looked this up online a little bit, and it seems like once a chromebook turns on, it remembers the amount of storage for its life. It seems like these people on reddit are having similar struggles: https://www.reddit.com/r/chromeos/commen...s/e4dyqi0/. Do you think if I deleted my current Chromium partitions and did the guide again, but resized the STATE partition before I booted into Chromium OS for the first time it would recognize the expanded storage? 

[Wizzard]

I really do not know, but I think you should try it.

[TDC_PBP]

I really do not know, but I think you should try it.

I think I figured it out! I deleted the partitions and followed the guide again, and discovered I hadn't changed all all of the   "${bootdevice}p${bootdevice_part}" references-just the first one aka I was still booting from the microsd card. When I was trying to resize the partition on the emmc it wasn't working because Chromium OS wasn't using it but the partition on the Microsd card! Thanks for your prompt reply anyway...