Hi Frank, On 06.06.2017, 00:20 -0700 Frank Rowand wrote:: > On 06/05/17 05:59, Stefani Seibold wrote: > > From: Stefani Seibold <stefani@xxxxxxxxxxx> > > > > This patch enables external references for symbols which are not > > exported by the current device tree. For example > > > > // RASPI example (only for testing) > > /dts-v1/; > > /plugin/; > > > > / { > > compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709"; > > > > fragment@0 { > > target-path = "/soc/i2s@7e203000"; > > __overlay__ { > > #address-cells = <0x00000001>; > > #size-cells = <0x00000001>; > > test = "test"; > > timer = <&timer>; > > }; > > }; > > > > __external_symbols__ { > > timer = "/soc/timer@7e003000"; > > }; > > }; > > My hope is that the dtc compiler will stop supporting specification > of the > __symbols__ node in dts source, and only generate it automatically in > the dtb. > That change to dtc would not allow any node name specified in a dts > to begin > with an underscore. Thus node __external_symbols__ would not be > allowed. > The name is not so important to me, only the solution. > > In case of the RASPI device tree this could be simple fixed by > > modifing > > the device tree source, but when the device tree is provided by a > > closed > > source BIOS this kind of missing symbol could not be fixed. > > Is there a real example of this issue, or is this a theoretical > concern? > If this is a real example, we should be discouraging such behavior. > Yes, I have a BIOS on some ARM64 servers which provides broken device tree. It also lacks some devices in this tree which needs references to other devices which lacks a phandle. > The suggestion by Pantelis should work, but that is just a hack to > get > you out of a bad situation, not a good practice. > I tried it, but it doesn't work. Look at my post to Pantelis. - Stefani -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html