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. > >> >> 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. > >> >> 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. 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
