[U-Boot] [RFC PATCH v1 0/9] Add support for applications of overlays in SPL

[Jean-Jacques Hiblot]

On 28/03/2019 14:54, Michal Simek wrote:
> On 25. 03. 19 9:08, Michal Simek wrote:
>> On 22. 03. 19 15:39, Jean-Jacques Hiblot wrote:
>>> The purpose of this series is to provide the SPL with ability to apply
>>> overlays for u-boot. this is only a RFC so far, to get a feedback on the
>>> approach.
>>>
>>> Our use-case is the support of the daughter boards of the AM65x EVM. In
>>> Linux, each board is supported by a unique overlay. The presence of the
>>> boards is detected at runtime, and some useful features (like USB) are
>>> implemented on those daughter boards. Instead of providing multiple dtbs
>>> and fall in a combinatorial pit, we propose to use DT overlays.
>> Not sure if you have it on these boards too but I expect you are able to
>> detect base board with this code board/ti/common/board_detect.c
>>
>> How do you detect these daughter cards? Is there additional I2C
>> connection to them and they have on board eeprom with any format for
>> detection?
Yes. There is EEPROM and GPIOs involved in the detection process.
>> Something similar what it is part of FMC standard/VITA 57.1 with using
>> FRU spec for daughter card description?
>> Anyway we are working on FRU parser exactly for this purpose.
>>
>> Do you also need to apply that overlays in SPL?
We need to apply in SPL so that u-boot has the right information in the DT.
>> Isn't it enough to apply them as the part of board_fdt_blob_setup()?
No it's possible to do that in board_fdt_blob_setup().
> I see v2 now but without answering my questions here.

Yes I had prepared the answer and forgot to push the send button.

in the V2 the biggest change is when the list of additional images is 
obtained from the board. It is now in spl_fit_get_image_name() and that 
makes its usable for other kind of binaries than just overlays.


JJ

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