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. > >> >>> >>>> >>>>> >>>>>> >>>>>> 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.. Thanks, Jagan. > Regards, > Simon > >> >> Thanks, >> Jagan. >> >>> >>>> >>>> Thanks, >>>> Jagan. >>>> >>>>> >>>>>> >>>>>> I saw that all tegra boards config files are defining >>>>>> CONFIG_DEFAULT_DEVICE_TREE if ie. the case dts is a compile time >>>>>> option right. >>>>>> am i correct? >>>>> >>>>> Yes - see above. This is convenient for testing and development. >>>>> >>>>>> >>>>>> Please let me know your inputs. >>>>> >>>>> Regards, >>>>> Simon >>>>> >>>>>> >>>>>> -- >>>>>> Thanks, >>>>>> Jagan. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
