4 --------------------------------------------------
5 This file records the order in which modules appear in Makefiles. This
6 is used by modprobe to deterministically resolve aliases that match
10 --------------------------------------------------
11 This file lists all modules that are built into the kernel. This is used
12 by modprobe to not fail when trying to load something builtin.
18 --------------------------------------------------
19 Additional options to pass when preprocessing. The preprocessing options
20 will be used in all cases where kbuild does preprocessing including
21 building C files and assembler files.
24 --------------------------------------------------
25 Additional options to the assembler (for built-in and modules).
28 --------------------------------------------------
29 Additional module specific options to use for $(AS).
32 --------------------------------------------------
33 Additional options for $(AS) when used for assembler
34 code for code that is compiled as built-in.
37 --------------------------------------------------
38 Additional options to the C compiler (for built-in and modules).
41 --------------------------------------------------
42 Additional options for $(CC) when used to compile
43 code that is compiled as built-in.
46 --------------------------------------------------
47 Additional module specific options to use for $(CC).
50 --------------------------------------------------
51 Additional options used for $(LD) when linking modules.
54 --------------------------------------------------
55 Additional options passed to final link of vmlinux.
58 --------------------------------------------------
59 Set the kbuild verbosity. Can be assigned same values as "V=...".
60 See make help for the full list.
61 Setting "V=..." takes precedence over KBUILD_VERBOSE.
64 --------------------------------------------------
65 Set the directory to look for the kernel source when building external
67 The directory can be specified in several ways:
68 1) Use "M=..." on the command line
69 2) Environment variable KBUILD_EXTMOD
70 3) Environment variable SUBDIRS
71 The possibilities are listed in the order they take precedence.
72 Using "M=..." will always override the others.
75 --------------------------------------------------
76 Specify the output directory when building the kernel.
77 The output directory can also be specified using "O=...".
78 Setting "O=..." takes precedence over KBUILD_OUTPUT.
81 --------------------------------------------------
82 For the deb-pkg target, allows overriding the normal heuristics deployed by
83 deb-pkg. Normally deb-pkg attempts to guess the right architecture based on
84 the UTS_MACHINE variable, and on some architectures also the kernel config.
85 The value of KBUILD_DEBARCH is assumed (not checked) to be a valid Debian
89 --------------------------------------------------
90 Set ARCH to the architecture to be built.
91 In most cases the name of the architecture is the same as the
92 directory name found in the arch/ directory.
93 But some architectures such as x86 and sparc have aliases.
94 x86: i386 for 32 bit, x86_64 for 64 bit
95 sparc: sparc for 32 bit, sparc64 for 64 bit
98 --------------------------------------------------
99 Specify an optional fixed part of the binutils filename.
100 CROSS_COMPILE can be a part of the filename or the full path.
102 CROSS_COMPILE is also used for ccache in some setups.
105 --------------------------------------------------
106 Additional options for sparse.
107 CF is often used on the command-line like this:
109 make CF=-Wbitwise C=2
112 --------------------------------------------------
113 INSTALL_PATH specifies where to place the updated kernel and system map
114 images. Default is /boot, but you can set it to other values.
117 --------------------------------------------------
118 Install script called when using "make install".
119 The default name is "installkernel".
121 The script will be called with the following arguments:
123 $2 - kernel image file
125 $4 - default install path (use root directory if blank)
127 The implementation of "make install" is architecture specific
128 and it may differ from the above.
130 INSTALLKERNEL is provided to enable the possibility to
131 specify a custom installer when cross compiling a kernel.
134 --------------------------------------------------
135 Specify where to install modules.
136 The default value is:
138 $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
140 The value can be overridden in which case the default value is ignored.
143 --------------------------------------------------
144 INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
145 relocations required by build roots. This is not defined in the
146 makefile but the argument can be passed to make if needed.
149 --------------------------------------------------
150 INSTALL_MOD_STRIP, if defined, will cause modules to be
151 stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
152 the default option --strip-debug will be used. Otherwise,
153 INSTALL_MOD_STRIP value will be used as the options to the strip command.
156 --------------------------------------------------
157 INSTALL_HDR_PATH specifies where to install user space headers when
158 executing "make headers_*".
159 The default value is:
163 $(objtree) is the directory where output files are saved.
164 The output directory is often set using "O=..." on the commandline.
166 The value can be overridden in which case the default value is ignored.
169 --------------------------------------------------
170 This variable allows a passphrase or PIN to be passed to the sign-file
171 utility when signing kernel modules, if the private key requires such.
174 --------------------------------------------------
175 KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined
176 symbols in the final module linking stage. It changes such errors
179 KBUILD_MODPOST_NOFINAL
180 --------------------------------------------------
181 KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
182 This is solely useful to speed up test compiles.
185 --------------------------------------------------
186 For modules that use symbols from other modules.
187 See more details in modules.txt.
190 --------------------------------------------------
191 For tags/TAGS/cscope targets, you can specify more than one arch
192 to be included in the databases, separated by blank space. E.g.:
194 $ make ALLSOURCE_ARCHS="x86 mips arm" tags
196 To get all available archs you can also specify all. E.g.:
198 $ make ALLSOURCE_ARCHS=all tags
200 KBUILD_ENABLE_EXTRA_GCC_CHECKS
201 --------------------------------------------------
202 If enabled over the make command line with "W=1", it turns on additional
203 gcc -W... options for more extensive build-time checking.
205 KBUILD_BUILD_TIMESTAMP
206 --------------------------------------------------
207 Setting this to a date string overrides the timestamp used in the
208 UTS_VERSION definition (uname -v in the running kernel). The value has to
209 be a string that can be passed to date -d. The default value
210 is the output of the date command at one point during build.
212 KBUILD_BUILD_USER, KBUILD_BUILD_HOST
213 --------------------------------------------------
214 These two variables allow to override the user@host string displayed during
215 boot and in /proc/version. The default value is the output of the commands
216 whoami and host, respectively.
219 --------------------------------------------------
220 The linker script with full path. Assigned by the top-level Makefile.
223 --------------------------------------------------
224 All object files for the init (first) part of vmlinux.
225 Files specified with KBUILD_VMLINUX_INIT are linked first.
228 --------------------------------------------------
229 All object files for the main part of vmlinux.
232 --------------------------------------------------
233 All .a "lib" files for vmlinux.
234 KBUILD_VMLINUX_INIT, KBUILD_VMLINUX_MAIN, and KBUILD_VMLINUX_LIBS together
235 specify all the object files used to link vmlinux.