Commit | Line | Data |
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acc08b51 SR |
1 | Environment variables |
2 | ||
3 | KCPPFLAGS | |
4 | -------------------------------------------------- | |
5 | Additional options to pass when preprocessing. The preprocessing options | |
df291fa9 | 6 | will be used in all cases where kbuild does preprocessing including |
acc08b51 SR |
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 | -------------------------------------------------- | |
df291fa9 | 19 | Set the kbuild verbosity. Can be assigned same values as "V=...". |
acc08b51 SR |
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=...". | |
df291fa9 | 38 | Setting "O=..." takes precedence over KBUILD_OUTPUT. |
acc08b51 SR |
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. | |
df291fa9 | 45 | But some architectures such as x86 and sparc have aliases. |
acc08b51 SR |
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 | |
df291fa9 | 66 | images. Default is /boot, but you can set it to other values. |
acc08b51 | 67 | |
caa27b66 SR |
68 | INSTALLKERNEL |
69 | -------------------------------------------------- | |
70 | Install script called when using "make install". | |
71 | The default name is "installkernel". | |
72 | ||
73 | The script will be called with the following arguments: | |
74 | $1 - kernel version | |
75 | $2 - kernel image file | |
76 | $3 - kernel map file | |
77 | $4 - default install path (use root directory if blank) | |
78 | ||
79 | The implmentation of "make install" is architecture specific | |
80 | and it may differ from the above. | |
81 | ||
82 | INSTALLKERNEL is provided to enable the possibility to | |
83 | specify a custom installer when cross compiling a kernel. | |
acc08b51 SR |
84 | |
85 | MODLIB | |
86 | -------------------------------------------------- | |
87 | Specify where to install modules. | |
88 | The default value is: | |
89 | ||
90 | $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) | |
91 | ||
92 | The value can be overridden in which case the default value is ignored. | |
93 | ||
94 | INSTALL_MOD_PATH | |
95 | -------------------------------------------------- | |
96 | INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory | |
97 | relocations required by build roots. This is not defined in the | |
98 | makefile but the argument can be passed to make if needed. | |
99 | ||
100 | INSTALL_MOD_STRIP | |
101 | -------------------------------------------------- | |
102 | INSTALL_MOD_STRIP, if defined, will cause modules to be | |
103 | stripped after they are installed. If INSTALL_MOD_STRIP is '1', then | |
104 | the default option --strip-debug will be used. Otherwise, | |
105 | INSTALL_MOD_STRIP will used as the options to the strip command. | |
106 | ||
107 | INSTALL_FW_PATH | |
108 | -------------------------------------------------- | |
df291fa9 | 109 | INSTALL_FW_PATH specifies where to install the firmware blobs. |
acc08b51 SR |
110 | The default value is: |
111 | ||
112 | $(INSTALL_MOD_PATH)/lib/firmware | |
113 | ||
114 | The value can be overridden in which case the default value is ignored. | |
115 | ||
116 | INSTALL_HDR_PATH | |
117 | -------------------------------------------------- | |
df291fa9 | 118 | INSTALL_HDR_PATH specifies where to install user space headers when |
acc08b51 SR |
119 | executing "make headers_*". |
120 | The default value is: | |
121 | ||
122 | $(objtree)/usr | |
123 | ||
124 | $(objtree) is the directory where output files are saved. | |
125 | The output directory is often set using "O=..." on the commandline. | |
126 | ||
127 | The value can be overridden in which case the default value is ignored. | |
128 | ||
129 | KBUILD_MODPOST_WARN | |
130 | -------------------------------------------------- | |
df291fa9 RD |
131 | KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined |
132 | symbols in the final module linking stage. It changes such errors | |
133 | into warnings. | |
acc08b51 | 134 | |
df291fa9 | 135 | KBUILD_MODPOST_NOFINAL |
acc08b51 SR |
136 | -------------------------------------------------- |
137 | KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. | |
df291fa9 | 138 | This is solely useful to speed up test compiles. |
acc08b51 SR |
139 | |
140 | KBUILD_EXTRA_SYMBOLS | |
141 | -------------------------------------------------- | |
df291fa9 | 142 | For modules that use symbols from other modules. |
acc08b51 | 143 | See more details in modules.txt. |
4f628248 JS |
144 | |
145 | ALLSOURCE_ARCHS | |
146 | -------------------------------------------------- | |
df291fa9 RD |
147 | For tags/TAGS/cscope targets, you can specify more than one arch |
148 | to be included in the databases, separated by blank space. E.g.: | |
4f628248 JS |
149 | |
150 | $ make ALLSOURCE_ARCHS="x86 mips arm" tags |