Am 21.11.2015 um 18:41 schrieb Stefan Bruens: > On Saturday 21 November 2015 13:59:00 Andreas Färber wrote: >> Do we have any actual example of such a cape dtb package that's not >> self-made? I encountered and dropped some binary .dtb files in >> raspberrypi-firmware package, other than that I am not aware of any. >> And when self-made, doesn't that involve having a modified kernel-source >> package? > > For RPi, you *need* an overlay/modified dtb to enable the SPI controller. It > is also useful to *configure* any SPI or I2C connected devices, e.g. RTCs, > touchscreen controllers, LCD controllers. [...]
That's no answer. For me, an overlay is something external to be merged into the DT, not just a modified .dts/.dtb. I would like to know where we have any real geiger-counter cape or SPI dtb packaged. If we don't have any, this whole discussion is highly theoretical. I am guessing from READMEs that bootcode.bin has the ability to manipulate the DT, enabling/disabling nodes and possibly more. But we boot U-Boot from bootcode.bin and thus cannot use those facilities. In a boot.scr such modifications could be scripted via fdt command. But how is the kernel involved in overlays? From what I see, we can only supply one .dtb to the kernel, not a base one plus a list of overlays. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton; HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
