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 SR |
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 | -------------------------------------------------- | |
df291fa9 | 93 | INSTALL_FW_PATH specifies where to install the firmware blobs. |
acc08b51 SR |
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 | -------------------------------------------------- | |
df291fa9 | 102 | INSTALL_HDR_PATH specifies where to install user space headers when |
acc08b51 SR |
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 | -------------------------------------------------- | |
df291fa9 RD |
115 | KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined |
116 | symbols in the final module linking stage. It changes such errors | |
117 | into warnings. | |
acc08b51 | 118 | |
df291fa9 | 119 | KBUILD_MODPOST_NOFINAL |
acc08b51 SR |
120 | -------------------------------------------------- |
121 | KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. | |
df291fa9 | 122 | This is solely useful to speed up test compiles. |
acc08b51 SR |
123 | |
124 | KBUILD_EXTRA_SYMBOLS | |
125 | -------------------------------------------------- | |
df291fa9 | 126 | For modules that use symbols from other modules. |
acc08b51 | 127 | See more details in modules.txt. |
4f628248 JS |
128 | |
129 | ALLSOURCE_ARCHS | |
130 | -------------------------------------------------- | |
df291fa9 RD |
131 | For tags/TAGS/cscope targets, you can specify more than one arch |
132 | to be included in the databases, separated by blank space. E.g.: | |
4f628248 JS |
133 | |
134 | $ make ALLSOURCE_ARCHS="x86 mips arm" tags |