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Diffstat (limited to 'Documentation/kbuild/makefiles.rst')
| -rw-r--r-- | Documentation/kbuild/makefiles.rst | 67 |
1 files changed, 25 insertions, 42 deletions
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index f4f0f7ffde2b..6ba9d5365ff3 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -471,21 +471,6 @@ more details, with real examples. The second argument is optional, and if supplied will be used if first argument is not supported. - cc-ldoption - cc-ldoption is used to check if $(CC) when used to link object files - supports the given option. An optional second option may be - specified if first option are not supported. - - Example:: - - #arch/x86/kernel/Makefile - vsyscall-flags += $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) - - In the above example, vsyscall-flags will be assigned the option - -Wl$(comma)--hash-style=sysv if it is supported by $(CC). - The second argument is optional, and if supplied will be used - if first argument is not supported. - as-instr as-instr checks if the assembler reports a specific instruction and then outputs either option1 or option2 @@ -765,7 +750,8 @@ Files matching the patterns "*.[oas]", "*.ko", plus some additional files generated by kbuild are deleted all over the kernel src tree when "make clean" is executed. -Additional files can be specified in kbuild makefiles by use of $(clean-files). +Additional files or directories can be specified in kbuild makefiles by use of +$(clean-files). Example:: @@ -776,23 +762,8 @@ When executing "make clean", the file "crc32table.h" will be deleted. Kbuild will assume files to be in the same relative directory as the Makefile, except if prefixed with $(objtree). -To delete a directory hierarchy use: - - Example:: - - #scripts/package/Makefile - clean-dirs := $(objtree)/debian/ - -This will delete the directory debian in the toplevel directory, including all -subdirectories. - -To exclude certain files from make clean, use the $(no-clean-files) variable. -This is only a special case used in the top level Kbuild file: - - Example:: - - #Kbuild - no-clean-files := $(bounds-file) $(offsets-file) +To exclude certain files or directories from make clean, use the +$(no-clean-files) variable. Usually kbuild descends down in subdirectories due to "obj-* := dir/", but in the architecture makefiles where the kbuild infrastructure @@ -988,13 +959,25 @@ When kbuild executes, the following steps are followed (roughly): $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic mode) if this option is supported by $(AR). - ARCH_CPPFLAGS, ARCH_AFLAGS, ARCH_CFLAGS Overrides the kbuild defaults + KBUILD_LDS + + The linker script with full path. Assigned by the top-level Makefile. + + KBUILD_LDS_MODULE + + The module linker script with full path. Assigned by the top-level + Makefile and additionally by the arch Makefile. + + KBUILD_VMLINUX_OBJS + + All object files for vmlinux. They are linked to vmlinux in the same + order as listed in KBUILD_VMLINUX_OBJS. - These variables are appended to the KBUILD_CPPFLAGS, - KBUILD_AFLAGS, and KBUILD_CFLAGS, respectively, after the - top-level Makefile has set any other flags. This provides a - means for an architecture to override the defaults. + KBUILD_VMLINUX_LIBS + All .a "lib" files for vmlinux. KBUILD_VMLINUX_OBJS and + KBUILD_VMLINUX_LIBS together specify all the object files used to + link vmlinux. 6.2 Add prerequisites to archheaders ------------------------------------ @@ -1139,7 +1122,7 @@ When kbuild executes, the following steps are followed (roughly): header-test-y - header-test-y specifies headers (*.h) in the current directory that + 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. @@ -1147,11 +1130,11 @@ When kbuild executes, the following steps are followed (roughly): header-test-pattern-y This works as a weaker version of header-test-y, and accepts wildcard - patterns. The typical usage is: + patterns. The typical usage is:: - header-test-pattern-y += *.h + header-test-pattern-y += *.h - This specifies all the files that matches to '*.h' in the current + 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 |