Op 5 nov. 2012, om 21:40 heeft Grant Likely <grant.likely@xxxxxxxxxxxx> het volgende geschreven: > Hey folks, > > As promised, here is my early draft to try and capture what device > tree overlays need to do and how to get there. Comments and > suggestions greatly appreciated. > > Device Tree Overlay Feature > > Purpose > ======= > Sometimes it is not convenient to describe an entire system with a > single FDT. For example, processor modules that are plugged into one or > more modules (a la the BeagleBone), or systems with an FPGA peripheral > that is programmed after the system is booted. > > For these cases it is proposed to implement an overlay feature for the > so that the initial device tree data can be modified by userspace at > runtime by loading additional overlay FDTs that amend the original data. > > User Stories > ============ > Note - These are potential use cases, but just because it is listed here > doesn't mean it is important. I just want to thoroughly think through the > implications before making design decisions. I think the beaglebone use cases cover it as well, but it deserves a seperate mention: SOMs. Gumstix is a good example of those, their website has a list of the different expansionboards they sell so we can see if we missed a use case somewhere. Their expansionboards have an EEPROM to ID them, just like the beagleboard classic/xM expansionboards, but I don't know if all 3rd party vendors honour that standard. I know the Ettus USRP E-100 on my desk has it. regards, Koen-- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
