Hi, Here are the 5th version of the patchset to enable kernel embedded bootconfig for non-initrd kernel boot environment. This version fixes to sort .gitignore and fixes lib/Makefile to cleanup default.bconf correctly and to allow user to specify a relative path to CONFIG_EMBED_BOOT_CONFIG_FILE. (Thanks Masahiro!) Also this update the document patch about the relative path. Here is the previous thread [1]. [1] https://lore.kernel.org/all/164833878595.2575750.1483106296151574233.stgit@devnote2/T/#u You can embed a bootconfig file into the kernel as a default bootconfig, which will be used if there is no initrd or no bootconfig is attached to initrd. This needs 2 options: CONFIG_EMBED_BOOT_CONFIG=y and set the file path to CONFIG_EMBED_BOOT_CONFIG_FILE. Even if you embed the bootconfig file to the kernel, it will not be enabled unless you pass "bootconfig" kernel command line option at boot. Moreover, since this is just a "default" bootconfig, you can override it with a new bootconfig if you attach another bootconfig to the initrd (if possible). CONFIG_EMBED_BOOT_CONFIG_FILE can take both absolute and relative path, but to simplify and make it independent from the build environment, I recommend you to use an absolute path for that. This is requested by Padmanabha at the below thread[2]; [2] https://lore.kernel.org/all/20220307184011.GA2570@pswork/T/#u KNOWN ISSUE: According to the report from Padmanabha[3] and my analysis [4], the embedded bootconfig data may not be updated if you do incremental build the kernel with CONFIG_LTO_CLANG_THIN. [3] https://lore.kernel.org/all/20220321183500.GA4065@pswork/T/#u [4] https://lore.kernel.org/all/20220327115526.cc4b0ff55fc53c97683c3e4d@xxxxxxxxxx/ This seems like clang's LTO Thin mode issue. It may not detect the inline asm depends on external files. I think the possible workaround is to split the inline asm which includes '.incbin' directive into an asm file. But this should be done in another seires because there are other features which uses '.incbin'. (e.g. /proc/config.gz) Thank you, --- Masami Hiramatsu (3): bootconfig: Check the checksum before removing the bootconfig from initrd bootconfig: Support embedding a bootconfig file in kernel docs: bootconfig: Add how to embed the bootconfig into kernel Documentation/admin-guide/bootconfig.rst | 31 +++++++++++++++++++++++++++--- include/linux/bootconfig.h | 10 ++++++++++ init/Kconfig | 21 ++++++++++++++++++++ init/main.c | 31 +++++++++++++++--------------- lib/.gitignore | 1 + lib/Makefile | 9 +++++++++ lib/bootconfig.c | 23 ++++++++++++++++++++++ 7 files changed, 108 insertions(+), 18 deletions(-) -- Masami Hiramatsu (Linaro) <mhiramat@xxxxxxxxxx>
