Hi, On Sun, Feb 24, 2013 at 9:55 AM, Jagan Teki <jagannadh.t...@gmail.com> wrote: > Hi Simon, > > On Sun, Feb 24, 2013 at 11:18 PM, Simon Glass <s...@chromium.org> wrote: >> Hi Jegan, >> >> On Sun, Feb 24, 2013 at 9:45 AM, Jagan Teki <jagannadh.t...@gmail.com> wrote: >>> Hi Simon, >>> >>> On Sun, Feb 24, 2013 at 11:08 PM, Simon Glass <s...@chromium.org> wrote: >>>> Hi Jagan, >>>> >>>> On Sun, Feb 24, 2013 at 8:19 AM, Jagan Teki <jagannadh.t...@gmail.com> >>>> wrote: >>>>> Hi Simon, >>>>> >>>>> Thanks for your response, please find my below comments. >>>>> >>>>> On Sun, Feb 24, 2013 at 9:24 PM, Simon Glass <s...@chromium.org> wrote: >>>>>> Hi Jagan, >>>>>> >>>>>> On Thu, Feb 21, 2013 at 9:03 AM, Jagan Teki <jagannadh.t...@gmail.com> >>>>>> wrote: >>>>>>> Hi All, >>>>>>> >>>>>>> I am planning to use devicetree on u-boot. >>>>>>> I have an experience to work with devicetree on Linux. >>>>>>> >>>>>>> For u-boot, I have read doc from doc/README.fdt-control. >>>>>>> I see some dts usages on tegra boards. >>>>>>> >>>>>>> I have lot of confusions with the concept itself. >>>>>>> >>>>>>> Is Linux and u-boot devicetree concept and build system are same? >>>>>> >>>>>> I don't really understand this question sorry. U-Boot and Linux use >>>>>> the device tree mainly for run-time configuration of drivers, so that >>>>>> the same driver code can operate on different boards. >>>>> >>>>> I am some how confusing the fdt usage in u-boot. >>>>> Because when compared to Linux, u-boot fdt setup mandatory to require >>>>> the CONFIG_DEFAULT_DEVICE_TREE >>>>> on the config file [from your previous comments]. >>>>> >>>>> is this the only difference when compared to Linux i guess..is it? >>>>> Linux defconfig file does need to hot-code >>>>> the dts. >>>> >>>> Yes - that is a difference. Linux provides a way to build .dts files >>>> but it is not mandatory. At present it is mandatory with U-Boot, and >>>> only one file is built. It can easily be ignored though. >>> >>> Ok. >>> >>>> >>>>> >>>>>> >>>>>>> >>>>>>> Suppose I have 4 boards J1, J2, J3 & J4 on my soc "emb".of vendor "vast" >>>>>>> For this requirement I have >>>>>>> board/vast/dts/J1.dts >>>>>>> board/vast/dts/J2.dts >>>>>>> board/vast/dts/J3.dts >>>>>>> board/vast/dts/J4.dts >>>>>>> >>>>>>> include/configs/emb_common.h ==> single configuration of all SOC >>>>>>> needed definitions >>>>>>> like defconfig in Linux. >>>>>>> >>>>>>> do I need any more files? >>>>>> >>>>>> That's enough for the basics I think. >>>>> >>>>> Is dtsi file require to add it on arch folder along with above. >>>> >>>> If your architecture is not one of those already supported (like arm >>>> tegra/exynos and x86) then yes you need to add this file in >>>> arch/<arch>/dts. What architecture are you using? >>> >>> My architecture is armv7, may be for me dtsi not required as arm is >>> existing architecture >>> to support fdt on u-boot.. is it? >> >> Which sub-arch? If it is tegra/exynos5250 then you might be OK. For >> something else, you should get the kernel's .dtsi file for that chip. > > I am having armv7, xilinx zynq soc..but i coun't get any .dtsi on kernel > source. > may be I will create new one.
OK, well if the kernel doesn't have FDT support yet then yes you will need to create a new one. > >> >>> >>>> >>>>> >>>>>> >>>>>>> >>>>>>> In emb_common.h i am defining >>>>>>> CONFIG_OF_SEPARATE is it sufficient? >>>>>> >>>>>> And CONFIG_OF_CONTROL >>>>>> >>>>>>> >>>>>>> My plan is to build u-boot and then build the dtb with specific >>>>>>> board and then combine. >>>>>> >>>>>> That's fine, and is how we do things on Chromium also. U-Boot tries to >>>>>> build an FDT even with CONFIG_OF_SEPARATE, so you need to put a >>>>>> default device tree file in your emb_common.h file that it can find. >>>>>> But you can ignore it, and for flashing your boards just use >>>>>> u-boot.bin plus whatever .dtb you want to select. >>>>> >>>>> So I will add the fdt support and then build the u-boot. >>>>> Is there any separate u-boot build command to build dts file. >>>>> My plan is to combine both u-boot and dtb. >>>> >>>> You can run dtc yourself if you like - see Makefile/dts for how it is >>>> done there. Once you have the .dtb binary, the easiest thing is to add >>>> it to the end of u-boot.bin, as described in README.fdt-control. >>> >>> Thanks, I tried with above setup for adding dts. >>> I have added simple dts file on my board. >>> >>> I got the below build error >>> /proj/mypc/u-boot/include/asm/gpio.h:1:27: fatal error: >>> asm/arch/gpio.h: No such file or directory >>> compilation terminated. >>> make[1]: *** No rule to make target `.depend.fdtdec', needed by >>> `.depend'. Stop. >>> >>> is gpio.h is mandatory for fdt build? >> >> Yes because basic GPIO support is included. You can create one for >> your sub-arch and make it #include <asm-generic/gpio.h> as a starting >> point. >> > > Should I create an empty gpio.h file..it still asking some gpio > definitions right.. It might be OK if you just have "#include <asm-generic/gpio.h>" in that file. Regads, Simon [snip] _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
