[OpenWrt-Devel] [PATCH] brcm2708: add squashfs rootfs image

Stijn Tintel stijn at linux-ipv6.be
Tue Apr 24 13:56:38 EDT 2018

On 24-04-18 19:17, Stijn Tintel wrote:
> On 24-04-18 17:59, Christian Lamparter wrote:
>> On Dienstag, 24. April 2018 13:29:17 CEST Stijn Tintel wrote:
>>> On 27-03-18 20:42, Christian Lamparter wrote:
>>>> This patch adds a image with squashfs as the root filesystem.
>>>> A rootfs_data partition will be generated on the first boot
>>>> and placed inside the rootfs partition (just after the squashfs
>>>> image).
>>>> advantages:
>>>>  - it is possible to migrate from an existing -ext4
>>>>    installation and back via sysupgrade.
>>>>  - existing partition layout will not be lost.
>>>>  - slightly smaller image size.
>>>>  - support for attendedsysupgrade
>>>> disadvantages:
>>>>  - needs f2fs + tools as well. This is because fs-tools decides on the
>>>>    blocksize of the sdcard. So either f2fs or ext4 can get choosen as
>>>>    the rootfs_data filesystem (depends on the size of the root partition).
>>>>  - rootfs_data is placed into the rootfs partition. This makes
>>>>    it difficult for tools that expect a /dev/mmc0pX device.
>>>>    It also makes it difficult for data recovery tools since they
>>>>    might not expect to find a embedded partition or will be
>>>>    confused.
>>>> For people with existing build configurations: make sure to include mkf2fs
>>>> and f2fsck package into the image... Otherwise the new -squashfs image will
>>>> boot of a ram-overlay and won't keep the configurations after a reboot.
>>> Tried to sysupgrade one of my RPi0W from ext4 to squashfs, and it
>>> appeared to work at first, until I rebooted it again. Apparently the
>>> overlay is completely missing, the SD card only has /boot (FAT32) and /
>>> (squashfs). Can you please look into this?
>> I think know the problem. The commit-message mentions it and the symptoms
>> you are describing would fit. But just in case: can you please provide the
>> image's diffconfig (or full-config ... and I guess a bootlog wouldn't
>> hurt either - but it would be optional) to confirm?
> Please find diffconfig attached. The machine was running headless so I
> don't have a bootlog.
>> (I also tested it again on an uptodate "OpenWrt SNAPSHOT, r6759+2-9e848f901c"
>> with my rpi-b - which should be in the same family/subtarget as your RPi0W so
>> I can try your generated images as well.)
>>> If you can get it resolved I will merge the patch.
>> The original issue [0] has been addressed by this patch [1]. And indeed
>> the luci-app will now successfully generate a image (currently, only for the 
>> rpi-3 though!):
>> "openwrt-dbbb09d2658d5c2-brcm2708-bcm2710-rpi-3-ext4-sdcard.img.gz"
>> and install it.
>> this patch is therefore no longer necessary since it the existing ext4
>> images work as well. :) ... Plus the ext4 images don't confuse tools and
>> brains as much.
> I still find it useful, I've had way too many corrupted ext4 filesystems
> on my RPis, and I'm hoping squashfs + f2fs would be more reliable than
> ext4 on SD cards...
Read the commit message again, and I see what you mean. Must have
misread CONFIG_DEFAULT_mkf2fs=y as CONFIG_PACKAGE_mkf2fs=y. Too bad make
defconfig doesn't enable DEFAULT_PACKAGES. Sorry for the noise, I'll do
some more testing and accept this patch.

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