On Sun, Jul 21, 2019 at 12:38 AM Eugeniy Paltsev <eugeniy.palt...@synopsys.com> wrote: > > Hi Masahiro, > > On Sat, 2019-07-20 at 11:40 +0900, Masahiro Yamada wrote: > > On Sat, Jul 20, 2019 at 4:28 AM Eugeniy Paltsev > > <eugeniy.palt...@synopsys.com> wrote: > > > As of today we are able to pass custom flags to dtc compiler but not > > > to dtc preprocessor. > > > This ability is required for including some board-specific header files. > > > It allows us to pass defined constants to dts without their duplication > > > in several places. > > > > How to use this option in a useful way? > > > > I see a bunch of defined constants under include/dt-bindings/. > > > > If you are talking about code duplication across architectures, > > you can include arm dtsi from arm64 dts, or vice versa. > > This was made possible by the symbolic links > > in scripts/dtc/include-prefixes/. > > > > Could you please elaborate your issues if you cannot solve them > > by the current strategy? > > > > Here is the example: > > We have several FPGA-based boards (haps_hs, haps_hs_idu,...) which are > involved > in SW and HW automated verification. For some tests we randomize physical > memory > location so we patch 'CONFIG_LINUX_RAM_BASE' kconfig variable and 'memory' > node in > device tree. We want to keep number of patches as less as possible (to avoid > conflicts on their applying) so we want to avoid duplication and pass > 'CONFIG_LINUX_RAM_BASE' directly to dts by including it from > 'include/generated/autoconf.h': > > ----------------------------->8------------------------------------ > memory { > device_type = "memory"; > - /* CONFIG_LINUX_RAM_BASE needs to match low mem start */ > - reg = <0x80000000 0x20000000>; /* 512 */ > + reg = <CONFIG_LINUX_RAM_BASE 0x20000000>; /* 512 */
So, we need the kernel configuration to build DT? I am scared with this idea. I believe DT files should be able to be compiled irrespective of the .config because they are re-used for other projects. devicetree-rebasing is a subset of the kernel tree that collects DT. If you upstream that patch, this will be broken, at least. git://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git -- Best Regards Masahiro Yamada _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc