On 29. 03. 19 13:50, Jean-Jacques Hiblot wrote: > > 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
ok. >> 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 ok. Will play with this and will see. Thanks, Michal _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
