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Diffstat (limited to 'Documentation/kbuild/makefiles.rst')
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 9274cdcc9bd2..f4f0f7ffde2b 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -328,7 +328,7 @@ more details, with real examples. variable $(KBUILD_CFLAGS) and uses it for compilation flags for the entire tree. - asflags-y specifies options for assembling with $(AS). + asflags-y specifies assembler options. Example:: @@ -384,6 +384,7 @@ more details, with real examples. ----------------------- Kbuild tracks dependencies on the following: + 1) All prerequisite files (both `*.c` and `*.h`) 2) `CONFIG_` options used in all prerequisite files 3) Command-line used to compile target @@ -489,7 +490,7 @@ more details, with real examples. as-instr checks if the assembler reports a specific instruction and then outputs either option1 or option2 C escapes are supported in the test instruction - Note: as-instr-option uses KBUILD_AFLAGS for $(AS) options + Note: as-instr-option uses KBUILD_AFLAGS for assembler options cc-option cc-option is used to check if $(CC) supports a given option, and if @@ -905,7 +906,7 @@ When kbuild executes, the following steps are followed (roughly): vmlinux. The usage of $(call if_changed,xxx) will be described later. KBUILD_AFLAGS - $(AS) assembler flags + Assembler flags Default value - see top level Makefile Append or modify as required per architecture. @@ -948,16 +949,16 @@ When kbuild executes, the following steps are followed (roughly): to 'y' when selected. KBUILD_AFLAGS_KERNEL - $(AS) options specific for built-in + Assembler options specific for built-in $(KBUILD_AFLAGS_KERNEL) contains extra C compiler flags used to compile resident kernel code. KBUILD_AFLAGS_MODULE - Options for $(AS) when building modules + Assembler options specific for modules $(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that - are used for $(AS). + are used for assembler. From commandline AFLAGS_MODULE shall be used (see kbuild.txt). @@ -999,11 +1000,7 @@ When kbuild executes, the following steps are followed (roughly): ------------------------------------ The archheaders: rule is used to generate header files that - may be installed into user space by "make header_install" or - "make headers_install_all". In order to support - "make headers_install_all", this target has to be able to run - on an unconfigured tree, or a tree configured for another - architecture. + may be installed into user space by "make header_install". It is run before "make archprepare" when run on the architecture itself. @@ -1140,6 +1137,22 @@ When kbuild executes, the following steps are followed (roughly): In this example, extra-y is used to list object files that shall be built, but shall not be linked as part of built-in.a. + header-test-y + + header-test-y specifies headers (*.h) in the current directory that + should be compile tested to ensure they are self-contained, + i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled, + this builds them as part of extra-y. + + header-test-pattern-y + + This works as a weaker version of header-test-y, and accepts wildcard + patterns. The typical usage is: + + header-test-pattern-y += *.h + + This specifies all the files that matches to '*.h' in the current + directory, but the files in 'header-test-' are excluded. 6.7 Commands useful for building a boot image --------------------------------------------- |