[U-Boot] [PATCH] ARM: mx6: Enable MMC FS boot support

[Marek Vasut]

On 04/28/2016 09:02 PM, Tom Rini wrote:
> On Thu, Apr 28, 2016 at 08:29:47PM +0200, Marek Vasut wrote:
>> On 04/28/2016 08:06 PM, Tom Rini wrote:
>>> On Thu, Apr 28, 2016 at 03:40:45PM +0200, Marek Vasut wrote:
>>>> On 04/28/2016 03:36 PM, Stefano Babic wrote:
>>>>> Hi Marek,
>>>>>
>>>>> On 28/04/2016 13:03, Marek Vasut wrote:
>>>>>> On 04/28/2016 07:59 AM, Stefano Babic wrote:
>>>>>>> Hi Marek,
>>>>>>>
>>>>>>> On 28/04/2016 04:24, Peng Fan wrote:
>>>>>>>> Hi Marek,
>>>>>>>>
>>>>>>>> On Thu, Apr 28, 2016 at 01:06:07AM +0200, Marek Vasut wrote:
>>>>>>>>> Enable support for booting U-Boot image from filesystem instead of some
>>>>>>>>> random offset on the SD card. This makes the board usable by putting the
>>>>>>>>> u-boot.img to first partition of the SD card and writing the SPL this way:
>>>>>>>>> $ dd if=u-boot-with-spl.imx of=/dev/sdX seek=2 bs=512
>>>>>>>>
>>>>>>>> I once want to enable this for i.MX6UL, but was rejected.
>>>>>>>> Anyway I prefer load u-boot.img from filesystem.
>>>>>>>>
>>>>>>>
>>>>>>> Right - we have this discussion some times ago. The agreement we reach
>>>>>>> was to maintain SPL loading only from a raw image.
>>>>>>>
>>>>>>> https://www.mail-archive.com/u-boot@lists.denx.de/msg185432.html
>>>>>>
>>>>>> The feeling I get from the discussion you linked above and the
>>>>>> discussion here is that because user can be an idiot and delete
>>>>>> files at random, we should move back to the 80s 
>>>>>
>>>>> No U-Boot in the 80s.
>>>>>
>>>>>> and store files
>>>>>> like on the casette tapes, at random offset. User can also delete
>>>>>> kernel image and yet, we store it on the filesystem. Maybe we should
>>>>>> also store the kernel image at another raw offset ... and hey, maybe
>>>>>> we should ditch filesystem altogether, just tar everything up and
>>>>>> store it at yet another offset, since user might delete files at
>>>>>> random, just imaging he'd delete libc ...
>>>>>
>>>>> wandboard has a market quite similar to the Raspi and yes, there is a
>>>>> lot of inexperienced people using it.
>>>>
>>>> Shall I prepare a patch which places kernel to yet another ad-hoc
>>>> location on the SD card then and tweak bootargs to use cramfs then?
>>>
>>> Users bricking their devices is a real problem.  I don't object to
>>> adding support for many ways of doing things (we have it on TI boards
>>> today) enabled, but saying there's no use case nor reason to do non-FS
>>> installs is also missing the mark.
>>
>> I am convinced this patch does not remove the "fallback to legacy
>> behavior" though.
> 
> Good.  Then you need to shove this up and over to the right common
> location since all of the offsets are, or better be (or we have a
> problem here..) the same for all imx6 and probably falling back a while
> too.  I know on TI parts the "magic" locations go back farther than
> U-Boot still supports.  And I know that might take a little time which
> is fine, this isn't a patch that needs to be in for v2016.05.
> 
Hm, grumble, the thing is falling apart the more I drill into it. There
will be a few more patches needed to deal with this raw legacy. Sigh ...

-- 
Best regards,
Marek Vasut