Hi Viresh, I made these comments in the v2 patch series. I am copying them here since this is the current version. On 1/12/21 2:29 AM, Viresh Kumar wrote: > We will start building overlays for platforms soon in the kernel and > would need fdtoverlay going forward. Lets start building it. > > The fdtoverlay program applies (or merges) one ore more overlay dtb > blobs to a base dtb blob. The kernel build system would later use > fdtoverlay to generate the overlaid blobs based on platform specific > configurations. > > Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> > --- > scripts/dtc/Makefile | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile > index 4852bf44e913..5f19386a49eb 100644 > --- a/scripts/dtc/Makefile > +++ b/scripts/dtc/Makefile > @@ -1,13 +1,17 @@ > # SPDX-License-Identifier: GPL-2.0 > # scripts/dtc makefile > > -hostprogs-always-$(CONFIG_DTC) += dtc > +hostprogs-always-$(CONFIG_DTC) += dtc fdtoverlay > hostprogs-always-$(CHECK_DT_BINDING) += dtc > > dtc-objs := dtc.o flattree.o fstree.o data.o livetree.o treesource.o \ > srcpos.o checks.o util.o > dtc-objs += dtc-lexer.lex.o dtc-parser.tab.o > # The upstream project builds libfdt as a separate library. We are choosing to # instead directly link the libfdt object files into fdtoverly > +libfdt-objs := fdt.o fdt_ro.o fdt_wip.o fdt_sw.o fdt_rw.o fdt_strerror.o fdt_empty_tree.o fdt_addresses.o fdt_overlay.o > +libfdt = $(addprefix libfdt/,$(libfdt-objs)) > +fdtoverlay-objs := $(libfdt) fdtoverlay.o util.o > + > # Source files need to get at the userspace version of libfdt_env.h to compile > HOST_EXTRACFLAGS += -I $(srctree)/$(src)/libfdt > > In general, I am a proponent of using shared libraries (which the upstream project builds by default) because if a security bug in the library is fixed, it is fixed for all users of the library. In this specific case, I actually prefer the implementation that the patch provides (directly linking the library object files into fdtoverlay, which uses the library) because it is the only user of the library _and_ fdtoverlay will not inadvertently use the system wide libfdt if it happens to be installed (as it is on my system). Any thoughts on this Rob? -Frank
