How to change rootfs from official RPI3 image

Ricky Zhang zhangchaowang at gmail.com
Sat Aug 24 10:15:40 UTC 2019


Hi Ronald,

After migrating to UFS, I read from BSD Journal May/2019 (https://www.freebsdfoundation.org/past-issues/freebsd-for-makers/). RPI3 can boot from ZFS rootfs.

So I tried it on my own (see the step details below in method 2):

https://github.com/rickyzhang82/FreeBSDWiki/wiki/1.-Migrate-SD-card-rootfs-to-SSD-for-RPI3#method-2-sd-card-kernel-boot--ssd-zfs-rootfs

Unfortunately, it hangs when try to mount root from dataset tank/rootfs. 

I read between lines that the the author in the BSD Journal only mount /var and /usr from ZFS dataset. The rest of rootfs still comes from SD card ufs partition.

My way moved the whole rootfs and home to tank/rootfs and tank/home dataset. When it boots, I saw my USB SSD LED is flashing periodically. The screen prints “Try to mount root from tank/roofs[]...". It seems to me that the kernel struggled to find the zpool from SSD. I saw that zfs module gets loaded properly from the screen. I have added two module in /boot/loader.conf as Internet suggest:

...
opensolaris_load="YES"
zfs_load="YES”
...

If I unplug USB SSD without any settings change, hit Ctrl-C. I can override mount root from command line at run time with "ufs:ufs/rootfs” rathe than “zfs:tank/rootfs". Then I can boot from SD card as before. Once I login, I can run zfs list and show both tank/rootfs and tank/home data set. So that confirmed my ZFS pool can be found. But somehow the boot process messed up somewhere.

Do you have any suggestion?

thanks
Ricky


> On Aug 21, 2019, at 8:15 AM, Ronald Klop <ronald-lists at klop.ws> wrote:
> 
> Thanks. I will not take the credits for the idea though. :-)
> The FreeBSD wiki has some more examples of similar setups:
> https://wiki.freebsd.org/ZFSOnRoot describes how to do /boot on UFS and the rest on ZFS, which is similar to /boot on SD-card and the rest on SSD.
> https://wiki.freebsd.org/RootOnZFS/UFSBoot
> 
> Nice that you made a write up also. More exposure for FreeBSD is always a good thing. :-)
> 
> Good luck and keep hacking.
> 
> Ronald.
> Van: Ricky Zhang <zhangchaowang at gmail.com>
> Datum: woensdag, 21 augustus 2019 13:16
> Aan: Ronald Klop <ronald-lists at klop.ws>
> CC: freebsd-arm at freebsd.org
> Onderwerp: Re: How to change rootfs from official RPI3 image
> 
> Your idea is brilliant. It solved the dilemma. 
>  
> Ricky at router ~ $ sudo cat /etc/fstab
> # Custom /etc/fstab for FreeBSD embedded images
> /dev/ufs/rootfs   /bootdir       ufs     rw      1       1
> /dev/label/gpt/ssdrootfs   /       ufs     rw      1       1
> /dev/msdosfs/MSDOSBOOT /boot/msdos msdosfs rw,noatime 0 0
> tmpfs /tmp tmpfs rw,mode=1777,size=50m 0 0
>  
> Ricky at router ~ $ mount
> /dev/label/gpt/ssdrootfs on / (ufs, local, soft-updates)
> devfs on /dev (devfs, local, multilabel)
> /dev/ufs/rootfs on /bootdir (ufs, local, soft-updates)
> /dev/msdosfs/MSDOSBOOT on /bootdir/boot/msdos (msdosfs, local, noatime)
> tmpfs on /tmp (tmpfs, local)
>  
> I wrote the whole thing down in my wiki: https://github.com/rickyzhang82/FreeBSDWiki/wiki/1.-Migrate-SD-card-rootfs-to-SSD-for-RPI3
>  
> Thanks
>  
> Ricky
>  
> On Aug 21, 2019, at 5:56 AM, Ronald Klop <ronald-lists at klop.ws> wrote:
>  
> Sorry, I did only reply to the mailinglist. I will use reply-all now.
> 
> You are right about uboot finding /boot/kernel and /boot/loader.conf.
> 
> What you need to do is mount the SD-card on /bootdir; in fstab:
> /dev/yoursdcard /bootdir ufs rw,noatime 1 2
> 
> And a symlink from /boot -> /bootdir/boot on your SSD.
> 
> Then installworld/installkernel will do the proper thing.
> So the complete /boot stays on the SD-card.
> 
> Regards,
> 
> Ronald.
> Van: Ricky Zhang <zhangchaowang at gmail.com>
> Datum: woensdag, 21 augustus 2019 04:58
> Aan: freebsd-arm at freebsd.org
> Onderwerp: Re: How to change rootfs from official RPI3 image
> 
> > BTW: Yes, u-boot is opensource: /usr/ports/sysutils/u-boot-rpi3
> > There are sysutils/u-boot-* ports for different system. With sysutils/u-boot-master as the main part of it.
> >
> > https://www.freshports.org/sysutils/u-boot-rpi3 <https://www.freshports.org/sysutils/u-boot-rpi3>
> > http://www.denx.de/wiki/U-Boot <http://www.denx.de/wiki/U-Boot>
> >
> > Regards,
> > Ronald.
> 
> 
> Hi Ronald,
> 
> Sorry, if I messed up the mailing list thread. I didn’t receive your email directly. Instead, I got your reply from daily digest. I have to copy subject and quote your reply manually in my email client. I have no idea how to fix it after reading all FAQ (https://www.freebsd.org/doc/en_US.ISO8859-1/articles/mailing-list-faq/article.html#etiquette <https://www.freebsd.org/doc/en_US.ISO8859-1/articles/mailing-list-faq/article.html#etiquette>). Any other mailing list I subscribed didn’t work this way...
> 
> In any case, the magic works. I did rsync:
> 
> rsync -aAXvr --progress --delete /* /mnt/USB \
>     --exclude='/boot/msdos/*' \
>     --exclude='/dev/*' \
>     --exclude='/proc/*' \
>     --exclude='/net/*' \
>     --exclude='/tmp/*' \
>     --exclude='/mnt/*' \
>     --exclude='/media/*'
> 
> I confirmed that it mount ssd as rootfs:
> 
> Ricky at router ~ $ df -h
> Filesystem                  Size    Used   Avail Capacity  Mounted on
> /dev/label/gpt/ssdrootfs    407G    5.5G    369G     1%    /
> devfs                       1.0K    1.0K      0B   100%    /dev
> /dev/msdosfs/MSDOSBOOT       50M     13M     37M    26%    /boot/msdos
> tmpfs                        50M    4.0K     50M     0%    /tmp
> 
> As you said, kernel still comes from SD card. I don’t fully understand the FreeBSD boot process. Neither am I familiar with UEFI.
> 
> - I guess /boot/msdos/uboot.bin finds the SD card roofs system. Load the kernel from /boot/kernel in SD card and scan /boot/loader.conf to find the rootfs. Please correct me if I’m wrong.
> - Should I remove /boot folder from SSD to avoid confusion?
> - Are there any guide how to compile and deploy kernel?
> 
> 
> 
> 
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