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| author | Masahiro Yamada <masahiroy@kernel.org> | 2024-09-23 16:56:03 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-11-04 17:53:09 +0900 |
| commit | 654102df2ac2a0d02a416100c3d44ff1dae932ca (patch) | |
| tree | 0bb8e0884e86c75ca24de2d4cf03e533f572cf29 /scripts/link-vmlinux.sh | |
| parent | 985d6cccb67c1943c687294095df04a031183fdb (diff) | |
kbuild: add generic support for built-in boot DTBs
Some architectures embed boot DTBs in vmlinux. A potential issue for
these architectures is a race condition during parallel builds because
Kbuild descends into arch/*/boot/dts/ twice.
One build thread is initiated by the 'dtbs' target, which is a
prerequisite of the 'all' target in the top-level Makefile:
ifdef CONFIG_OF_EARLY_FLATTREE
all: dtbs
endif
For architectures that support the built-in boot dtb, arch/*/boot/dts/
is visited also during the ordinary directory traversal in order to
build obj-y objects that wrap DTBs.
Since these build threads are unaware of each other, they can run
simultaneously during parallel builds.
This commit introduces a generic build rule to scripts/Makefile.vmlinux
to support embedded boot DTBs in a race-free way. Architectures that
want to use this rule need to select CONFIG_GENERIC_BUILTIN_DTB.
After the migration, Makefiles under arch/*/boot/dts/ will be visited
only once to build only *.dtb files.
This change also aims to unify the CONFIG options used for built-in DTBs
support. Currently, different architectures use different CONFIG options
for the same purposes.
With this commit, the CONFIG options will be unified as follows:
- CONFIG_GENERIC_BUILTIN_DTB
This enables the generic rule for built-in boot DTBs. This will be
renamed to CONFIG_BUILTIN_DTB after all architectures migrate to the
generic rule.
- CONFIG_BUILTIN_DTB_NAME
This specifies the path to the embedded DTB.
(relative to arch/*/boot/dts/)
- CONFIG_BUILTIN_DTB_ALL
If this is enabled, all DTB files compiled under arch/*/boot/dts/ are
embedded into vmlinux. Only used by MIPS.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'scripts/link-vmlinux.sh')
| -rwxr-xr-x | scripts/link-vmlinux.sh | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index a9b3f34a78d2..53bd4b727e21 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -68,6 +68,10 @@ vmlinux_link() libs="${KBUILD_VMLINUX_LIBS}" fi + if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then + objs="${objs} .builtin-dtbs.o" + fi + if is_enabled CONFIG_MODULES; then objs="${objs} .vmlinux.export.o" fi |