[PATCH 4/5] Add filetype and detection for squashfs images

[Yegor Yefremov]

Hi Enrico,

On Thu, Oct 6, 2016 at 4:10 PM, Enrico Joerns <ejo at pengutronix.de> wrote:
> Hi Yegor,
>
> On 10/06/2016 03:55 PM, Yegor Yefremov wrote:
>>
>> On Tue, Oct 4, 2016 at 12:10 PM, Enrico Jorns <ejo at pengutronix.de> wrote:
>>>
>>> This adds `filetype_squashfs` to the list of known filetypes and adds a
>>> detection for squashfs files to file_detect_type(). This currently
>>> matches on the `hsqs` start sequence of an image file.
>>>
>>> Additionally, the newly introduced filetype is registered as the type of
>>> the squashfs_driver which allows, for example, to mount squashfs without
>>> the need to specify a type parameter.
>>>
>>> This changes enable booting a squashfs with the simple `boot` command
>>> pointing to the location (device) that holds the squashfs.
>>>
>>> Note that booting with blspec is limited as the current squashfs driver
>>> is not capable of handling symbolic links.
>>
>>
>> Glad to see SquashFS will be used not only by myself :-)
>
>
> glad to see that, too ;)
>
>> Could you explain how one can write a rootfs.sqaushfs to a ubiblock
>> from Linux and then what steps are needed in barebox?
>>
>> So far I've only found this info about ubiblock:
>> http://www.linux-mtd.infradead.org/doc/ubi.html#L_ubiblock, but it
>> doesn't say much.
>
>
> Yes, the informations provided are a bit sparse..
>
>> My actions were:
>>
>> ubiattach -p /dev/mtd5
>> ubiblock --create /dev/ubi0_0
>> ubiupdatevol /dev/ubi0_0 rootfs.squashfs
>>
>> Can I mount /dev/ubi0_0 via mount? If yes, what parameters I should use?
>
>
> The above commands look pretty similar to what I did. Mounting the ubiblock
> device does work too, with a little pitfall, mount will be confused by
> having a read-only file system but nobody told it before.
> So you must do
>
>   mount -o ro /dev/ubiblock0_0 /mnt/test
>
>> How can I mount this volume in barebox step-by-step?
>
>
> Using it in barebox is pretty easy, as the ubiblock layer is not required
> there:
>
>   ubiattach /dev/nand0.root
>   ubiupdatevol /dev/nand0.root.ubi.ubivolname rootfs.squashfs
>   mkdir /mnt/test
>   mount /dev/nand0.root.ubi.ubivolname /mnt/test
>
>
> To boot via bootspec form a ubi containing a squashfs, you simply need to
>
>   boot /dev/nand0.root.ubi.ubivolname
>
>
> Hope that helps.

Everything is working like a charm. I just had a problem with my
ccache and hence both my kernel and barebox got compiled without
squashfs support :-)

So here is my:

Tested-by: Yegor Yefremov <yegorslists at googlemail.com>

Thanks.

Yegor