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

[Jean-Jacques Hiblot]

On 29/03/2019 11:26, Michal Simek wrote:
> On 29. 03. 19 11:13, Jean-Jacques Hiblot wrote:
>> 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.
> Does that mean that you use gpio bitbanging i2c eeprom to read information?
no, on am65 we use GPIOs and a true I2C to detect the daughter boards
> x
>
>>>> 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().
> A little bit confused by your response. yes/no?
I forgot a key word here. it is not possible. board_fdt_blob_setup is 
used to provide a DTB blob
>
>
>>> 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.
> Yes I have seen that. Give me some time to test this.
> As I said V2 looks better.
>
> M
>
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