Hi Stephen, On Tue, Oct 11, 2011 at 4:37 PM, Stephen Warren <[email protected]> wrote: > Simon Glass wrote at Tuesday, October 11, 2011 4:26 PM: > ... >> and add some defines to your board (only ARM is currently supported): >> >> #define CONFIG_OF_CONTROL (to enable run-time config control via fdt) >> #define CONFIG_OF_EMBED or CONFIG_OF_SEPARATE >> (either build the fdt blob into U-Boot, or create a separate u-boot.dtb >> and u-boot-dtb.bin) >> #define CONFIG_DEFAULT_DEVICE_TREE "<your name>" >> (to specify the name of the device tree file is >> board/<vendor>/dts/<your name>.dts) >> >> Typically a CPU device tree include file is provided which defines all the >> devices available on that CPU/SOC, with each set to 'status = "disabled"'. >> Board device tree files should adjust only the devices they use, setting >> 'status = 'ok"' in each case, and leaving the existing devices alone and >> disabled. > > s/existing/other/ in the second-to-last line? Well, I guess given this is > patch 0, that's not important.
Will fix. > > In the Linux kernel, things used to work exactly as described above, but > the kernel has switched to having no "status" properties in the SoC base > file (and hence everything defaults to enabled), with the per-board .dts > files set 'status = "disabled"' where desired. I imagine U-Boot should > follow the same practice. > > I forget the exact reason for this in the kernel; it may simply have been > due to precedent on PowerPC. Grant Likely would know the details. Well it's going to create a bit of work for boards that use only a subset of these 30-peripheral SOCs, but perhaps the expectation is that you would be buying a simpler SOC if you didn't need all the features. > > ... >> For example, for Tegra2 we might have in arch/arm/cpu/armv7/tegra2/config.mk >> these lines: >> >> CONFIG_ARCH_DEVICE_TREE := tegra250 >> >> This means that ARCH_CPU_DTS will point to arch/arm/dts/tegra250.dtsi. > > In the kernel, we renamed this to tegra20; "Tegra 250" is a marketing name, > whereas "Tegra 20" is an engineering name. Engineering names should be more > stable, and probably fewer in number, and so are more suitable for device- > tree. > > (I guess that's not particularly important for this patchset, since it > doesn't include tegra250.dtsi, but it'll be relevant soon I'm sure:-) Yes I did see that on the list. I will change the message in this patch set, and try to remember when we get to 'soon' :-) Regards, Simon > > -- > nvpublic > > _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
