|
@@ -40,10 +40,16 @@ This document describes the Linux kernel Makefiles.
|
|
--- 6.7 Custom kbuild commands
|
|
--- 6.7 Custom kbuild commands
|
|
--- 6.8 Preprocessing linker scripts
|
|
--- 6.8 Preprocessing linker scripts
|
|
|
|
|
|
- === 7 Kbuild Variables
|
|
|
|
- === 8 Makefile language
|
|
|
|
- === 9 Credits
|
|
|
|
- === 10 TODO
|
|
|
|
|
|
+ === 7 Kbuild syntax for exported headers
|
|
|
|
+ --- 7.1 header-y
|
|
|
|
+ --- 7.2 objhdr-y
|
|
|
|
+ --- 7.3 destination-y
|
|
|
|
+ --- 7.4 unifdef-y (deprecated)
|
|
|
|
+
|
|
|
|
+ === 8 Kbuild Variables
|
|
|
|
+ === 9 Makefile language
|
|
|
|
+ === 10 Credits
|
|
|
|
+ === 11 TODO
|
|
|
|
|
|
=== 1 Overview
|
|
=== 1 Overview
|
|
|
|
|
|
@@ -1143,8 +1149,69 @@ When kbuild executes, the following steps are followed (roughly):
|
|
The kbuild infrastructure for *lds file are used in several
|
|
The kbuild infrastructure for *lds file are used in several
|
|
architecture-specific files.
|
|
architecture-specific files.
|
|
|
|
|
|
|
|
+=== 7 Kbuild syntax for exported headers
|
|
|
|
+
|
|
|
|
+The kernel include a set of headers that is exported to userspace.
|
|
|
|
+Many headers can be exported as-is but other headers requires a
|
|
|
|
+minimal pre-processing before they are ready for user-space.
|
|
|
|
+The pre-processing does:
|
|
|
|
+- drop kernel specific annotations
|
|
|
|
+- drop include of compiler.h
|
|
|
|
+- drop all sections that is kernel internat (guarded by ifdef __KERNEL__)
|
|
|
|
+
|
|
|
|
+Each relevant directory contain a file name "Kbuild" which specify the
|
|
|
|
+headers to be exported.
|
|
|
|
+See subsequent chapter for the syntax of the Kbuild file.
|
|
|
|
+
|
|
|
|
+ --- 7.1 header-y
|
|
|
|
+
|
|
|
|
+ header-y specify header files to be exported.
|
|
|
|
+
|
|
|
|
+ Example:
|
|
|
|
+ #include/linux/Kbuild
|
|
|
|
+ header-y += usb/
|
|
|
|
+ header-y += aio_abi.h
|
|
|
|
+
|
|
|
|
+ The convention is to list one file per line and
|
|
|
|
+ preferably in alphabetic order.
|
|
|
|
+
|
|
|
|
+ header-y also specify which subdirectories to visit.
|
|
|
|
+ A subdirectory is identified by a trailing '/' which
|
|
|
|
+ can be seen in the example above for the usb subdirectory.
|
|
|
|
+
|
|
|
|
+ Subdirectories are visited before their parent directories.
|
|
|
|
+
|
|
|
|
+ --- 7.2 objhdr-y
|
|
|
|
+
|
|
|
|
+ objhdr-y specifies generated files to be exported.
|
|
|
|
+ Generated files are special as they need to be looked
|
|
|
|
+ up in another directory when doing 'make O=...' builds.
|
|
|
|
+
|
|
|
|
+ Example:
|
|
|
|
+ #include/linux/Kbuild
|
|
|
|
+ objhdr-y += version.h
|
|
|
|
+
|
|
|
|
+ --- 7.3 destination-y
|
|
|
|
+
|
|
|
|
+ When an architecture have a set of exported headers that needs to be
|
|
|
|
+ exported to a different directory destination-y is used.
|
|
|
|
+ destination-y specify the destination directory for all exported
|
|
|
|
+ headers in the file where it is present.
|
|
|
|
+
|
|
|
|
+ Example:
|
|
|
|
+ #arch/xtensa/platforms/s6105/include/platform/Kbuild
|
|
|
|
+ destination-y := include/linux
|
|
|
|
+
|
|
|
|
+ In the example above all exported headers in the Kbuild file
|
|
|
|
+ will be located in the directory "include/linux" when exported.
|
|
|
|
+
|
|
|
|
+
|
|
|
|
+ --- 7.4 unifdef-y (deprecated)
|
|
|
|
+
|
|
|
|
+ unifdef-y is deprecated. A direct replacement is header-y.
|
|
|
|
+
|
|
|
|
|
|
-=== 7 Kbuild Variables
|
|
|
|
|
|
+=== 8 Kbuild Variables
|
|
|
|
|
|
The top Makefile exports the following variables:
|
|
The top Makefile exports the following variables:
|
|
|
|
|
|
@@ -1206,7 +1273,7 @@ The top Makefile exports the following variables:
|
|
INSTALL_MOD_STRIP will used as the option(s) to the strip command.
|
|
INSTALL_MOD_STRIP will used as the option(s) to the strip command.
|
|
|
|
|
|
|
|
|
|
-=== 8 Makefile language
|
|
|
|
|
|
+=== 9 Makefile language
|
|
|
|
|
|
The kernel Makefiles are designed to be run with GNU Make. The Makefiles
|
|
The kernel Makefiles are designed to be run with GNU Make. The Makefiles
|
|
use only the documented features of GNU Make, but they do use many
|
|
use only the documented features of GNU Make, but they do use many
|
|
@@ -1225,14 +1292,14 @@ time the left-hand side is used.
|
|
There are some cases where "=" is appropriate. Usually, though, ":="
|
|
There are some cases where "=" is appropriate. Usually, though, ":="
|
|
is the right choice.
|
|
is the right choice.
|
|
|
|
|
|
-=== 9 Credits
|
|
|
|
|
|
+=== 10 Credits
|
|
|
|
|
|
Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net>
|
|
Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net>
|
|
Updates by Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de>
|
|
Updates by Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de>
|
|
Updates by Sam Ravnborg <sam@ravnborg.org>
|
|
Updates by Sam Ravnborg <sam@ravnborg.org>
|
|
Language QA by Jan Engelhardt <jengelh@gmx.de>
|
|
Language QA by Jan Engelhardt <jengelh@gmx.de>
|
|
|
|
|
|
-=== 10 TODO
|
|
|
|
|
|
+=== 11 TODO
|
|
|
|
|
|
- Describe how kbuild supports shipped files with _shipped.
|
|
- Describe how kbuild supports shipped files with _shipped.
|
|
- Generating offset header files.
|
|
- Generating offset header files.
|