Re: [RAUC] Query regarding rauc

[Enrico Joerns <ejo@pengutronix.de>]

Hi Abhishek,

On 12/4/18 12:12 PM, Abhishek Kumar Rai wrote:
> Hi Team,
> 
> 
> To achieve a specific requirement for us the "rauc install" command won't work i.e due to a configuration that we have the rauc install would fail. Though we would still like to go ahead and flashload to that partition. We would like to know if the approach below is correct
> 
> 
> Our understanding of rauc install suggests that it does the following things:
> 
>  1. Verify signature of the bundle
>  2. Run partition selection algorithm
>  3. Extract the tar balls from the bundle
>  4. Create new ext4 FS on the selected partition
>  5. Write appropriate tar ball to the partition
> 
> 
> Since "rauc install" would give us errors due to our configuration we plan to achieve this using the steps below:
> 
>  1. Verify signature of the bundle (rauc info ...)
>  2. Partition selection algorithm (we would like to skip this)
>  3. Extract the tar balls from the bundle (rauc extract ..)
>  4. Create new ext4 FS on the selected partition + Write appropriate tar ball to the partition (rauc write-slot ... ....)

how do you trigger the custom installation? Do you use the full-custom RAUC install handler?

Extracting the tar's should not be required in all cases. With the full-custom handler you
will already have it mounted, otherwise you can simply mount the bundle after verification
as it is basically a squashfs.

For rauc write-slot you also rely on parts of the system.conf, but not in the fixed scheme.
If that is where your issue resides, you should be fine with that.


Could you give me a hint what forces you to do this kind of manual handling?
Maybe then we can think about a possible solution more targeted.

But basically it should work as described above, yes.
One thing will miss, depending on what you actually try to do.
The key for atomic updates is to deactivate the bootable slot you
write your image to before writing and set it as primary after successful writing.

You can achieve this behavior with

   rauc status mark-bad <slot-to-update>

   [ perform update ]

   rauc status mark-active <slot-to-update>


Best regards, Enrico

-- 
Pengutronix e.K.                           | Enrico Jörns                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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