[U-Boot] [PATCH 4/9] ARM: socfpga: Bundle U-Boot fitImage into SFP on Arria10

[Marek Vasut]

On 11/28/2018 03:43 PM, Chee, Tien Fong wrote:
> On Tue, 2018-11-27 at 13:09 +0100, Marek Vasut wrote:
>> On 11/27/2018 10:00 AM, Chee, Tien Fong wrote:
>>>
>>> On Mon, 2018-11-26 at 12:22 +0100, Marek Vasut wrote:
>>>>
>>>> On 11/26/2018 11:30 AM, Chee, Tien Fong wrote:
>>>>>
>>>>>
>>>>> On Fri, 2018-11-23 at 13:40 +0100, Marek Vasut wrote:
>>>>>>
>>>>>>
>>>>>> On 11/23/2018 10:54 AM, Chee, Tien Fong wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Wed, 2018-11-21 at 15:21 +0100, Marek Vasut wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 11/21/2018 11:41 AM, tien.fong.chee at intel.com wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> From: Tien Fong Chee <tien.fong.chee at intel.com>
>>>>>>>> Did you change Author:ship of the patch ?
>>>>>> I believe you did, so please fix that.
>>>>> Very sorry. I din't realize the author name was changed.
>>>> Please be careful next time.
>>> Sure.
>>>>
>>>>
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Bundle U-Boot fitImage containing U-Boot and FPGA
>>>>>>>>> bitstream
>>>>>>>>> into
>>>>>>>>> the
>>>>>>>>> u-boot-with-spl.sfp on Arria10. This lets U-Boot
>>>>>>>>> operate in
>>>>>>>>> a
>>>>>>>>> very
>>>>>>>>> similar fashion to Gen5, where the U-Boot binary got
>>>>>>>>> loaded
>>>>>>>>> by
>>>>>>>>> the
>>>>>>>>> SPL from a uImage concatenated at the end of the SPL
>>>>>>>>> SFP
>>>>>>>>> image.
>>>>>>>>> On
>>>>>>>>> Gen10, the U-Boot is in fitImage which contains the
>>>>>>>>> FPGA
>>>>>>>>> bitstream
>>>>>>>>> as well. In this case, the SPL can load the FPGA
>>>>>>>>> bitstream
>>>>>>>>> first
>>>>>>>>> and
>>>>>>>>> load the U-Boot afterward in the same manner. This is
>>>>>>>>> nonetheless a
>>>>>>>>> stopgap measure until there is a proper firmware loader
>>>>>>>>> in
>>>>>>>>> U-
>>>>>>>>> Boot.
>>>>>>>> Right, this is a stopgap measure until FW loader is
>>>>>>>> present.
>>>>>>>> Why
>>>>>>>> is
>>>>>>>> this
>>>>>>>> patch needed at all in this series ?
>>>>>>> This patch is cherry picked from the sdmmc_next custodian,
>>>>>>> so
>>>>>>> this
>>>>>>> patch is required for generating FIT image. I can remove
>>>>>>> the
>>>>>>> stopgap
>>>>>>> comment to avoid confusing.
>>>>>> But why is this patch needed at all ? You use the firmware
>>>>>> loader
>>>>>> to
>>>>>> load the FPGA bitstream. Where does the fitImage come into
>>>>>> play ?
>>>>>>
>>>>>> The fitImage was used to circumvent the missing FW loader,
>>>>>> when I
>>>>>> needed
>>>>>> to load multiple files (bitstream and u-boot binary). Now
>>>>>> there
>>>>>> is no
>>>>>> such requirement anymore, so the entire fitImage machinery is
>>>>>> probably
>>>>>> not needed ?
>>>>> Loading issue is not the reason we choose the fitImage. We
>>>>> choose
>>>>> it
>>>>> because it allows more flexibility in handling various type
>>>>> images,
>>>>> especially it allows user more choices to enhance integrity and
>>>>> security protection.
>>>> Do you need to load multiple images at all ? Do you need the
>>>> extra
>>>> flexibility or does it only bloat and slow down the boot process
>>>> for
>>>> no
>>>> benefit at all? If a user needs it, they can enable it, but do we
>>>> need
>>>> it by default ?
>>> Okay, then we add in the fitImage support and let user to enable
>>> it.
>>> So, without CONFIG_SPL_FIT is defined, then the boot process would
>>> be
>>> with individual files such as u-boot-dtb.img instead of u-boot.itb.
>> Yes, so all these fitImage patches can be dropped for now ?
> This patch can be dropped. But i don't know it is good idea to reserve
> the patch 5-8, this would be easier for user to enable CONFIG_SPL_FIT
> in future.

Drop them for now, let's revisit this later.

-- 
Best regards,
Marek Vasut