| Message ID | facca66aba8070ef8bdb075ec442287c81e7d23e.1610431620.git.viresh.kumar@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scripts: dtc: Build fdtoverlay | expand |
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@linaro.org> > --- > 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
On Tue, Jan 19, 2021 at 12:28 PM Frank Rowand <frowand.list@gmail.com> wrote: > > 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@linaro.org> > > --- > > 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? I agree. No point in complicating the build to do a library. Rob
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 +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
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@linaro.org> --- scripts/dtc/Makefile | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 2.25.0.rc1.19.g042ed3e048af