Re: [DistroKit] [PATCH 4/5] v8a: barebox: enable loading kernel, dtb and initrd via fastboot

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 06.06.23 16:54, Johannes Zink wrote:
> Hi Ahmad,
> 
> On 6/6/23 16:44, Ahmad Fatoum wrote:
>> On 06.06.23 16:31, Johannes Zink wrote:
>>> This allows to load kernel, dtb and initrd as sparse images to
>>> RAM-files.
>>>
>>> While at it, also enable the acm gadget, which exposes the barebox shell
>>> as an USB gadget and autostart the usb gadgets.
>>>
>>> Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
>>> ---
>>>   configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.acm        | 1 +
>>>   configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.bbu        | 1 +
>>>   configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.partitions | 1 +
>>>   configs/platform-v8a/barebox-common-defaultenv/nv/usbgadget.autostart | 1 +
>>>   4 files changed, 4 insertions(+)
>>>
>>> diff --git a/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.acm b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.acm
>>> new file mode 100644
>>> index 000000000000..d00491fd7e5b
>>> --- /dev/null
>>> +++ b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.acm
>>> @@ -0,0 +1 @@
>>> +1
>>> diff --git a/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.bbu b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.bbu
>>> new file mode 100644
>>> index 000000000000..d00491fd7e5b
>>> --- /dev/null
>>> +++ b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.bbu
>>> @@ -0,0 +1 @@
>>> +1
>>> diff --git a/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.partitions b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.partitions
>>> new file mode 100644
>>> index 000000000000..a67f90305dd6
>>> --- /dev/null
>>> +++ b/configs/platform-v8a/barebox-common-defaultenv/nv/fastboot.partitions
>>> @@ -0,0 +1 @@
>>> +/dev/mmc0(sd)o,/dev/mmc1(emmc)o,/tmp/kernel(kernel)c,/tmp/initramfs(initramfs)c,/tmp/oftree(oftree)c
>>
>> 1) Why not export the barebox update handler?
> 
> simple: I forgot to add it... will add it in v2.

You didn't. I now see fastboot.bbu above, which I missed the first time.

> 
>> 2) Is sd also mmc0 and emmc mmc1 on the i.MX8M boards? Because those use the
>>     same environment
> 
> not in general, no. Maybe use /dev/mmc0(mmc0)o,/dev/mmc1(mmc1)o,/dev/mmc2(mmc2)o instead?

Yes, this should do for now. Generally, I think barebox should just support exporting all
devices a user might be interested in. I submitted a patch for that:

https://lore.barebox.org/barebox/20230608072418.3275633-2-a.fatoum@pengutronix.de/T/#u

We could switch over to using this, once the patch is accepted and DistroKit is
updated to a release that has it (unless you want to pick it earlier).


Keep in mind that with either approach, only devices are functional
that barebox has detected. If you boot from SD, barebox might
not need to eMMC at all and thus it would not be detected unless you
(i.e. some init script) do 

  detect mmc0 mmc1 mmc2

Cheers,
Ahmad

>
> Johannes
> 
>>
>>> diff --git a/configs/platform-v8a/barebox-common-defaultenv/nv/usbgadget.autostart b/configs/platform-v8a/barebox-common-defaultenv/nv/usbgadget.autostart
>>> new file mode 100644
>>> index 000000000000..d00491fd7e5b
>>> --- /dev/null
>>> +++ b/configs/platform-v8a/barebox-common-defaultenv/nv/usbgadget.autostart
>>> @@ -0,0 +1 @@
>>> +1
>>>
>>
> 

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