blob: 0ff6a466a05b242bbba0a1ce9bf640b6a05fa8e7 [file] [log] [blame]
Michal Marekbc081dd2009-12-07 16:38:33 +01001Output files
2
3modules.order
4--------------------------------------------------
5This file records the order in which modules appear in Makefiles. This
6is used by modprobe to deterministically resolve aliases that match
7multiple modules.
8
9modules.builtin
10--------------------------------------------------
11This file lists all modules that are built into the kernel. This is used
12by modprobe to not fail when trying to load something builtin.
13
14
Sam Ravnborgacc08b52008-12-29 13:45:52 +010015Environment variables
16
17KCPPFLAGS
18--------------------------------------------------
19Additional options to pass when preprocessing. The preprocessing options
Randy Dunlapdf291fa2009-01-08 10:59:34 -080020will be used in all cases where kbuild does preprocessing including
Sam Ravnborgacc08b52008-12-29 13:45:52 +010021building C files and assembler files.
22
23KAFLAGS
24--------------------------------------------------
Sam Ravnborg65881692010-07-28 17:33:09 +020025Additional options to the assembler (for built-in and modules).
26
27AFLAGS_MODULE
28--------------------------------------------------
Lucas De Marchi25985ed2011-03-30 22:57:33 -030029Additional module specific options to use for $(AS).
Sam Ravnborgacc08b52008-12-29 13:45:52 +010030
Sam Ravnborg80c00ba2010-07-28 19:11:27 +020031AFLAGS_KERNEL
32--------------------------------------------------
Lucas De Marchi25985ed2011-03-30 22:57:33 -030033Additional options for $(AS) when used for assembler
Sam Ravnborg80c00ba2010-07-28 19:11:27 +020034code for code that is compiled as built-in.
Sam Ravnborgacc08b52008-12-29 13:45:52 +010035
36KCFLAGS
37--------------------------------------------------
Sam Ravnborg65881692010-07-28 17:33:09 +020038Additional options to the C compiler (for built-in and modules).
39
Sam Ravnborg80c00ba2010-07-28 19:11:27 +020040CFLAGS_KERNEL
41--------------------------------------------------
Lucas De Marchi25985ed2011-03-30 22:57:33 -030042Additional options for $(CC) when used to compile
Sam Ravnborg80c00ba2010-07-28 19:11:27 +020043code that is compiled as built-in.
44
Sam Ravnborg65881692010-07-28 17:33:09 +020045CFLAGS_MODULE
46--------------------------------------------------
Lucas De Marchi25985ed2011-03-30 22:57:33 -030047Additional module specific options to use for $(CC).
Sam Ravnborg65881692010-07-28 17:33:09 +020048
49LDFLAGS_MODULE
50--------------------------------------------------
51Additional options used for $(LD) when linking modules.
Sam Ravnborgacc08b52008-12-29 13:45:52 +010052
Sam Ravnborgd27579a2012-05-05 10:18:42 +020053LDFLAGS_vmlinux
54--------------------------------------------------
55Additional options passed to final link of vmlinux.
56
Sam Ravnborgacc08b52008-12-29 13:45:52 +010057KBUILD_VERBOSE
58--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -080059Set the kbuild verbosity. Can be assigned same values as "V=...".
Sam Ravnborgacc08b52008-12-29 13:45:52 +010060See make help for the full list.
61Setting "V=..." takes precedence over KBUILD_VERBOSE.
62
63KBUILD_EXTMOD
64--------------------------------------------------
65Set the directory to look for the kernel source when building external
66modules.
67The directory can be specified in several ways:
681) Use "M=..." on the command line
Nicolas Kaiserc95940f2010-08-05 11:23:11 -0700692) Environment variable KBUILD_EXTMOD
703) Environment variable SUBDIRS
Sam Ravnborgacc08b52008-12-29 13:45:52 +010071The possibilities are listed in the order they take precedence.
72Using "M=..." will always override the others.
73
74KBUILD_OUTPUT
75--------------------------------------------------
76Specify the output directory when building the kernel.
Nicolas Kaiserc95940f2010-08-05 11:23:11 -070077The output directory can also be specified using "O=...".
Randy Dunlapdf291fa2009-01-08 10:59:34 -080078Setting "O=..." takes precedence over KBUILD_OUTPUT.
Sam Ravnborgacc08b52008-12-29 13:45:52 +010079
Asbjoern Sloth Toennesen55f88ec2010-12-12 17:39:40 +000080KBUILD_DEBARCH
81--------------------------------------------------
82For the deb-pkg target, allows overriding the normal heuristics deployed by
83deb-pkg. Normally deb-pkg attempts to guess the right architecture based on
84the UTS_MACHINE variable, and on some architectures also the kernel config.
85The value of KBUILD_DEBARCH is assumed (not checked) to be a valid Debian
86architecture.
87
Sam Ravnborgacc08b52008-12-29 13:45:52 +010088ARCH
89--------------------------------------------------
90Set ARCH to the architecture to be built.
91In most cases the name of the architecture is the same as the
92directory name found in the arch/ directory.
Randy Dunlapdf291fa2009-01-08 10:59:34 -080093But some architectures such as x86 and sparc have aliases.
Sam Ravnborgacc08b52008-12-29 13:45:52 +010094x86: i386 for 32 bit, x86_64 for 64 bit
95sparc: sparc for 32 bit, sparc64 for 64 bit
96
97CROSS_COMPILE
98--------------------------------------------------
99Specify an optional fixed part of the binutils filename.
100CROSS_COMPILE can be a part of the filename or the full path.
101
Kirill Smelkove8d400a2010-02-17 11:45:33 +0300102CROSS_COMPILE is also used for ccache in some setups.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100103
104CF
105--------------------------------------------------
106Additional options for sparse.
107CF is often used on the command-line like this:
108
109 make CF=-Wbitwise C=2
110
111INSTALL_PATH
112--------------------------------------------------
113INSTALL_PATH specifies where to place the updated kernel and system map
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800114images. Default is /boot, but you can set it to other values.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100115
Sam Ravnborgcaa27b62009-07-20 21:37:11 +0200116INSTALLKERNEL
117--------------------------------------------------
118Install script called when using "make install".
119The default name is "installkernel".
120
121The script will be called with the following arguments:
122 $1 - kernel version
123 $2 - kernel image file
124 $3 - kernel map file
125 $4 - default install path (use root directory if blank)
126
Nicolas Kaiserc95940f2010-08-05 11:23:11 -0700127The implementation of "make install" is architecture specific
Sam Ravnborgcaa27b62009-07-20 21:37:11 +0200128and it may differ from the above.
129
130INSTALLKERNEL is provided to enable the possibility to
131specify a custom installer when cross compiling a kernel.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100132
133MODLIB
134--------------------------------------------------
135Specify where to install modules.
136The default value is:
137
138 $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
139
140The value can be overridden in which case the default value is ignored.
141
142INSTALL_MOD_PATH
143--------------------------------------------------
144INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
145relocations required by build roots. This is not defined in the
146makefile but the argument can be passed to make if needed.
147
148INSTALL_MOD_STRIP
149--------------------------------------------------
150INSTALL_MOD_STRIP, if defined, will cause modules to be
151stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
152the default option --strip-debug will be used. Otherwise,
Gilles Espinasse177b2412011-01-09 08:59:49 +0100153INSTALL_MOD_STRIP value will be used as the options to the strip command.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100154
155INSTALL_FW_PATH
156--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800157INSTALL_FW_PATH specifies where to install the firmware blobs.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100158The default value is:
159
160 $(INSTALL_MOD_PATH)/lib/firmware
161
162The value can be overridden in which case the default value is ignored.
163
164INSTALL_HDR_PATH
165--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800166INSTALL_HDR_PATH specifies where to install user space headers when
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100167executing "make headers_*".
168The default value is:
169
170 $(objtree)/usr
171
172$(objtree) is the directory where output files are saved.
173The output directory is often set using "O=..." on the commandline.
174
175The value can be overridden in which case the default value is ignored.
176
David Woodhouseaf1eb292015-07-20 21:16:28 +0100177KBUILD_SIGN_PIN
178--------------------------------------------------
179This variable allows a passphrase or PIN to be passed to the sign-file
180utility when signing kernel modules, if the private key requires such.
181
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100182KBUILD_MODPOST_WARN
183--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800184KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined
185symbols in the final module linking stage. It changes such errors
186into warnings.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100187
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800188KBUILD_MODPOST_NOFINAL
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100189--------------------------------------------------
190KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800191This is solely useful to speed up test compiles.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100192
193KBUILD_EXTRA_SYMBOLS
194--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800195For modules that use symbols from other modules.
Sam Ravnborgacc08b52008-12-29 13:45:52 +0100196See more details in modules.txt.
Jike Song4f628242009-01-05 14:57:03 +0800197
198ALLSOURCE_ARCHS
199--------------------------------------------------
Randy Dunlapdf291fa2009-01-08 10:59:34 -0800200For tags/TAGS/cscope targets, you can specify more than one arch
201to be included in the databases, separated by blank space. E.g.:
Jike Song4f628242009-01-05 14:57:03 +0800202
203 $ make ALLSOURCE_ARCHS="x86 mips arm" tags
John Kacurbc75cc62010-03-02 16:57:52 +0100204
205To get all available archs you can also specify all. E.g.:
206
207 $ make ALLSOURCE_ARCHS=all tags
Borislav Petkov4a5838a2011-03-01 09:35:29 +0100208
209KBUILD_ENABLE_EXTRA_GCC_CHECKS
210--------------------------------------------------
211If enabled over the make command line with "W=1", it turns on additional
212gcc -W... options for more extensive build-time checking.
Michal Marek53e68922011-04-05 14:32:30 +0200213
214KBUILD_BUILD_TIMESTAMP
215--------------------------------------------------
216Setting this to a date string overrides the timestamp used in the
Michal Mareka8b80172011-03-31 23:16:42 +0200217UTS_VERSION definition (uname -v in the running kernel). The value has to
218be a string that can be passed to date -d. The default value
Michal Marek53e68922011-04-05 14:32:30 +0200219is the output of the date command at one point during build.
220
221KBUILD_BUILD_USER, KBUILD_BUILD_HOST
222--------------------------------------------------
223These two variables allow to override the user@host string displayed during
224boot and in /proc/version. The default value is the output of the commands
225whoami and host, respectively.
Sam Ravnborgd27579a2012-05-05 10:18:42 +0200226
227KBUILD_LDS
228--------------------------------------------------
229The linker script with full path. Assigned by the top-level Makefile.
230
231KBUILD_VMLINUX_INIT
232--------------------------------------------------
233All object files for the init (first) part of vmlinux.
234Files specified with KBUILD_VMLINUX_INIT are linked first.
235
236KBUILD_VMLINUX_MAIN
237--------------------------------------------------
238All object files for the main part of vmlinux.
239KBUILD_VMLINUX_INIT and KBUILD_VMLINUX_MAIN together specify
240all the object files used to link vmlinux.