[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / kbuild / kbuild.txt

Environment variables

KCPPFLAGS
--------------------------------------------------
Additional options to pass when preprocessing. The preprocessing options
will be used in all cases where kbuild do preprocessing including
building C files and assembler files.

KAFLAGS
--------------------------------------------------
Additional options to the assembler.

KCFLAGS
--------------------------------------------------
Additional options to the C compiler.

KBUILD_VERBOSE
--------------------------------------------------
Set the kbuild verbosity. Can be assinged same values as "V=...".
See make help for the full list.
Setting "V=..." takes precedence over KBUILD_VERBOSE.

KBUILD_EXTMOD
--------------------------------------------------
Set the directory to look for the kernel source when building external
modules.
The directory can be specified in several ways:
1) Use "M=..." on the command line
2) Environmnet variable KBUILD_EXTMOD
3) Environmnet variable SUBDIRS
The possibilities are listed in the order they take precedence.
Using "M=..." will always override the others.

KBUILD_OUTPUT
--------------------------------------------------
Specify the output directory when building the kernel.
The output directory can also be specificed using "O=...".
Setting "O=..." takes precedence over KBUILD_OUTPUT

ARCH
--------------------------------------------------
Set ARCH to the architecture to be built.
In most cases the name of the architecture is the same as the
directory name found in the arch/ directory.
But some architectures suach as x86 and sparc has aliases.
x86: i386 for 32 bit, x86_64 for 64 bit
sparc: sparc for 32 bit, sparc64 for 64 bit

CROSS_COMPILE
--------------------------------------------------
Specify an optional fixed part of the binutils filename.
CROSS_COMPILE can be a part of the filename or the full path.

CROSS_COMPILE is also used for ccache is some setups.

CF
--------------------------------------------------
Additional options for sparse.
CF is often used on the command-line like this:

    make CF=-Wbitwise C=2

INSTALL_PATH
--------------------------------------------------
INSTALL_PATH specifies where to place the updated kernel and system map
images. Default is /boot, but you can set it to other values


MODLIB
--------------------------------------------------
Specify where to install modules.
The default value is:

     $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)

The value can be overridden in which case the default value is ignored.

INSTALL_MOD_PATH
--------------------------------------------------
INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
relocations required by build roots.  This is not defined in the
makefile but the argument can be passed to make if needed.

INSTALL_MOD_STRIP
--------------------------------------------------
INSTALL_MOD_STRIP, if defined, will cause modules to be
stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
the default option --strip-debug will be used.  Otherwise,
INSTALL_MOD_STRIP will used as the options to the strip command.

INSTALL_FW_PATH
--------------------------------------------------
INSTALL_FW_PATH specify where to install the firmware blobs.
The default value is:

    $(INSTALL_MOD_PATH)/lib/firmware

The value can be overridden in which case the default value is ignored.

INSTALL_HDR_PATH
--------------------------------------------------
INSTALL_HDR_PATH specify where to install user space headers when
executing "make headers_*".
The default value is:

    $(objtree)/usr

$(objtree) is the directory where output files are saved.
The output directory is often set using "O=..." on the commandline.

The value can be overridden in which case the default value is ignored.

KBUILD_MODPOST_WARN
--------------------------------------------------
KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
symbols in the final module linking stage.

KBUILD_MODPOST_FINAL
--------------------------------------------------
KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
This is solely usefull to speed up test compiles.

KBUILD_EXTRA_SYMBOLS
--------------------------------------------------
For modules use symbols from another modules.
See more details in modules.txt.
Commit	Line	Data
acc08b51 SR	1	Environment variables
	2
	3	KCPPFLAGS
	4	--------------------------------------------------
	5	Additional options to pass when preprocessing. The preprocessing options
	6	will be used in all cases where kbuild do preprocessing including
	7	building C files and assembler files.
	8
	9	KAFLAGS
	10	--------------------------------------------------
	11	Additional options to the assembler.
	12
	13	KCFLAGS
	14	--------------------------------------------------
	15	Additional options to the C compiler.
	16
	17	KBUILD_VERBOSE
	18	--------------------------------------------------
	19	Set the kbuild verbosity. Can be assinged same values as "V=...".
	20	See make help for the full list.
	21	Setting "V=..." takes precedence over KBUILD_VERBOSE.
	22
	23	KBUILD_EXTMOD
	24	--------------------------------------------------
	25	Set the directory to look for the kernel source when building external
	26	modules.
	27	The directory can be specified in several ways:
	28	1) Use "M=..." on the command line
	29	2) Environmnet variable KBUILD_EXTMOD
	30	3) Environmnet variable SUBDIRS
	31	The possibilities are listed in the order they take precedence.
	32	Using "M=..." will always override the others.
	33
	34	KBUILD_OUTPUT
	35	--------------------------------------------------
	36	Specify the output directory when building the kernel.
	37	The output directory can also be specificed using "O=...".
	38	Setting "O=..." takes precedence over KBUILD_OUTPUT
	39
	40	ARCH
	41	--------------------------------------------------
	42	Set ARCH to the architecture to be built.
	43	In most cases the name of the architecture is the same as the
	44	directory name found in the arch/ directory.
	45	But some architectures suach as x86 and sparc has aliases.
	46	x86: i386 for 32 bit, x86_64 for 64 bit
	47	sparc: sparc for 32 bit, sparc64 for 64 bit
	48
	49	CROSS_COMPILE
	50	--------------------------------------------------
	51	Specify an optional fixed part of the binutils filename.
	52	CROSS_COMPILE can be a part of the filename or the full path.
	53
	54	CROSS_COMPILE is also used for ccache is some setups.
	55
	56	CF
	57	--------------------------------------------------
	58	Additional options for sparse.
	59	CF is often used on the command-line like this:
	60
	61	make CF=-Wbitwise C=2
	62
	63	INSTALL_PATH
	64	--------------------------------------------------
65	INSTALL_PATH specifies where to place the updated kernel and system map
66	images. Default is /boot, but you can set it to other values
67
68
69	MODLIB
70	--------------------------------------------------
71	Specify where to install modules.
72	The default value is:
73
74	$(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
75
76	The value can be overridden in which case the default value is ignored.
77
78	INSTALL_MOD_PATH
79	--------------------------------------------------
80	INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
81	relocations required by build roots. This is not defined in the
82	makefile but the argument can be passed to make if needed.
83
84	INSTALL_MOD_STRIP
85	--------------------------------------------------
86	INSTALL_MOD_STRIP, if defined, will cause modules to be
87	stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
88	the default option --strip-debug will be used. Otherwise,
89	INSTALL_MOD_STRIP will used as the options to the strip command.
90
91	INSTALL_FW_PATH
92	--------------------------------------------------
93	INSTALL_FW_PATH specify where to install the firmware blobs.
94	The default value is:
95
96	$(INSTALL_MOD_PATH)/lib/firmware
97
98	The value can be overridden in which case the default value is ignored.
99
100	INSTALL_HDR_PATH
101	--------------------------------------------------
102	INSTALL_HDR_PATH specify where to install user space headers when
103	executing "make headers_*".
104	The default value is:
105
106	$(objtree)/usr
107
108	$(objtree) is the directory where output files are saved.
109	The output directory is often set using "O=..." on the commandline.
110
111	The value can be overridden in which case the default value is ignored.
112
113	KBUILD_MODPOST_WARN
114	--------------------------------------------------
115	KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
116	symbols in the final module linking stage.
117
118	KBUILD_MODPOST_FINAL
119	--------------------------------------------------
120	KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
121	This is solely usefull to speed up test compiles.
122
123	KBUILD_EXTRA_SYMBOLS
124	--------------------------------------------------
125	For modules use symbols from another modules.
126	See more details in modules.txt.