[PATCH 2/5] Description of _shipped files handling in kbuild
From: Nicholas Mc Guire
Date: Tue Dec 02 2014 - 04:23:08 EST
Description of _shipped files handling in kbuild
This adds a section on handling of _shipped files in Kbuild
Makefiles and the build process.
This patch is against linux 3.18.0-rc6
Signed-off-by: Nicholas Mc Guire <der.herr@xxxxxxx>
Documentation/kbuild/makefiles.txt | 58 +++++++++++++++++++++++++++++++++++-
1 file changed, 57 insertions(+), 1 deletion(-)
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index a311db8..df3a96a 100644
@@ -19,6 +19,7 @@ This document describes the Linux kernel Makefiles.
--- 3.10 Special Rules
--- 3.11 $(CC) support functions
--- 3.12 $(LD) support functions
+ --- 3.13 _shipped - generated files
=== 4 Host Program support
--- 4.1 Simple Host Program
@@ -594,6 +595,61 @@ more details, with real examples.
LDFLAGS_vmlinux += $(call ld-option, -X)
+--- 3.13 _shipped - generated files
+ Some sources in the kernel are generated by tools or special
+ purpose scripts so that the build process dependencies can be kept
+ at a reasonable level. Also in cases where the translation is not
+ configuration dependent but might impact build time, _shipped files
+ may be added along with the actual sources to speed up the build
+ For standard tools like lex and yacc the make process will actually
+ generate the _shipped files (see scripts/Makefile.lib) and retain
+ them by marking them .PRECIOUS so they are not removed by the clean
+ For non-standard tools the generation of the _shipped file itself
+ may be manually achieved by building and then renaming. A makefile
+ target to generate the actual target file should to be provided
+ though and can be conditioned on an environment variable.
+ ifdef GENERATE_KEYMAP
+ $(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map
+ loadkeys --mktable $< > $@
+ The _shipped file does not appear in the actual Makefile, this is
+ handled by the rules found in scripts/Makefile.lib.
+ cmd_shipped = cat $< > $@
+ $(obj)/%: $(src)/%_shipped
+ $(call cmd,shipped)
+ which simply will copy the target_shipped to the target
+ If a file of a make target is found in the build directory with the
+ extension _shipped, make will use it rather than generating the
+ respective target file from source.
+ The build will indicate the use of the _shipped file by the SHIPPED
+ quiet command in the make output.
+ LD drivers/scsi/aic7xxx/built-in.o
+ SHIPPED drivers/scsi/aic7xxx/aic79xx_seq.h
+ SHIPPED drivers/scsi/aic7xxx/aic79xx_reg.h
+ CC [M] drivers/scsi/aic7xxx/aic79xx_core.o
+ CC [M] drivers/scsi/aic7xxx/aic79xx_pci.o
+ SHIPPED drivers/scsi/aic7xxx/aic79xx_reg_print.c
+ CC [M] drivers/scsi/aic7xxx/aic79xx_reg_print.o
=== 4 Host Program support
@@ -1399,10 +1455,10 @@ Original version made by Michael Elizabeth Chastain, <mailto:mec@xxxxxxxxx>
Updates by Kai Germaschewski <kai@xxxxxxxxxxxxxxxxxxxxxx>
Updates by Sam Ravnborg <sam@xxxxxxxxxxxx>
Language QA by Jan Engelhardt <jengelh@xxxxxx>
+Kbuild support for shipped files Nicholas Mc Guire <der.herr@xxxxxxx>
=== 11 TODO
-- Describe how kbuild supports shipped files with _shipped.
- Generating offset header files.
- Add more variables to section 7?
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