On Mon, Nov 5, 2012 at 11:22 PM, Tony Lindgren <[email protected]> wrote: > Hi, > > * Tabi Timur-B04825 <[email protected]> [121105 13:42]: >> On Mon, Nov 5, 2012 at 2:40 PM, Grant Likely <[email protected]> >> wrote: >> >> > Jane is building custom BeagleBone expansion boards called 'capes'. She >> > can boot the system with a stock BeagleBoard device tree, but additional >> > data is needed before a cape can be used. She could replace the FDT file >> > used by U-Boot with one that contains the extra data, but she uses the >> > same Linux system image regardless of the cape, and it is inconvenient >> > to have to select a different device tree at boot time depending on the >> > cape. >> >> What's wrong with having the boot loader detect the presence of the >> Cape and update the device tree accordingly? We do this all the time >> in U-Boot. Doing stuff like reading EEPROMs and testing for the >> presence of hardware is easier in U-Boot than in Linux. >> >> For configurations that can be determined by the boot loader, I'm not >> sure overlays are practical. > > I guess the beaglebone capes could be stackable and hotpluggable if > handled carefully enough.
And even if it can't on the beaglebone, it will happen somewhere else. I don't want to exclude that use-case just because nobody thought about it. g. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
