Hi Simon, On Sun, Feb 24, 2013 at 11:55 PM, Jagan Teki <jagannadh.t...@gmail.com> wrote: > Hi Simon, > > On Sun, Feb 24, 2013 at 11:50 PM, Simon Glass <s...@chromium.org> wrote: >> 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. > > Thanks. > > Finally I have created u-boot-dtb.bin. > for building dtb separately I have used > $ make DEVICE_TREE=zynq .. it creates a u-boot.dtb > > is there any option for building separate name, for example I need to > create zynq.dtb
Some how I am able to create a fdt build on my target. But what is this gpio mandatory, because currently my target currently need a GPIO setup. Add ing gpio.h/ with equivalent definitions is an extra overhead is it? please explain. Thanks, Jagan. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
