| 1 | Output files |
| 2 | |
| 3 | modules.order |
| 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 |
| 7 | multiple modules. |
| 8 | |
| 9 | modules.builtin |
| 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. |
| 13 | |
| 14 | modules.builtin.modinfo |
| 15 | -------------------------------------------------- |
| 16 | This file contains modinfo from all modules that are built into the kernel. |
| 17 | Unlike modinfo of a separate module, all fields are prefixed with module name. |
| 18 | |
| 19 | |
| 20 | Environment variables |
| 21 | |
| 22 | KCPPFLAGS |
| 23 | -------------------------------------------------- |
| 24 | Additional options to pass when preprocessing. The preprocessing options |
| 25 | will be used in all cases where kbuild does preprocessing including |
| 26 | building C files and assembler files. |
| 27 | |
| 28 | KAFLAGS |
| 29 | -------------------------------------------------- |
| 30 | Additional options to the assembler (for built-in and modules). |
| 31 | |
| 32 | AFLAGS_MODULE |
| 33 | -------------------------------------------------- |
| 34 | Additional module specific options to use for $(AS). |
| 35 | |
| 36 | AFLAGS_KERNEL |
| 37 | -------------------------------------------------- |
| 38 | Additional options for $(AS) when used for assembler |
| 39 | code for code that is compiled as built-in. |
| 40 | |
| 41 | KCFLAGS |
| 42 | -------------------------------------------------- |
| 43 | Additional options to the C compiler (for built-in and modules). |
| 44 | |
| 45 | CFLAGS_KERNEL |
| 46 | -------------------------------------------------- |
| 47 | Additional options for $(CC) when used to compile |
| 48 | code that is compiled as built-in. |
| 49 | |
| 50 | CFLAGS_MODULE |
| 51 | -------------------------------------------------- |
| 52 | Additional module specific options to use for $(CC). |
| 53 | |
| 54 | LDFLAGS_MODULE |
| 55 | -------------------------------------------------- |
| 56 | Additional options used for $(LD) when linking modules. |
| 57 | |
| 58 | HOSTCFLAGS |
| 59 | -------------------------------------------------- |
| 60 | Additional flags to be passed to $(HOSTCC) when building host programs. |
| 61 | |
| 62 | HOSTCXXFLAGS |
| 63 | -------------------------------------------------- |
| 64 | Additional flags to be passed to $(HOSTCXX) when building host programs. |
| 65 | |
| 66 | HOSTLDFLAGS |
| 67 | -------------------------------------------------- |
| 68 | Additional flags to be passed when linking host programs. |
| 69 | |
| 70 | HOSTLDLIBS |
| 71 | -------------------------------------------------- |
| 72 | Additional libraries to link against when building host programs. |
| 73 | |
| 74 | KBUILD_KCONFIG |
| 75 | -------------------------------------------------- |
| 76 | Set the top-level Kconfig file to the value of this environment |
| 77 | variable. The default name is "Kconfig". |
| 78 | |
| 79 | KBUILD_VERBOSE |
| 80 | -------------------------------------------------- |
| 81 | Set the kbuild verbosity. Can be assigned same values as "V=...". |
| 82 | See make help for the full list. |
| 83 | Setting "V=..." takes precedence over KBUILD_VERBOSE. |
| 84 | |
| 85 | KBUILD_EXTMOD |
| 86 | -------------------------------------------------- |
| 87 | Set the directory to look for the kernel source when building external |
| 88 | modules. |
| 89 | Setting "M=..." takes precedence over KBUILD_EXTMOD. |
| 90 | |
| 91 | KBUILD_OUTPUT |
| 92 | -------------------------------------------------- |
| 93 | Specify the output directory when building the kernel. |
| 94 | The output directory can also be specified using "O=...". |
| 95 | Setting "O=..." takes precedence over KBUILD_OUTPUT. |
| 96 | |
| 97 | KBUILD_DEBARCH |
| 98 | -------------------------------------------------- |
| 99 | For the deb-pkg target, allows overriding the normal heuristics deployed by |
| 100 | deb-pkg. Normally deb-pkg attempts to guess the right architecture based on |
| 101 | the UTS_MACHINE variable, and on some architectures also the kernel config. |
| 102 | The value of KBUILD_DEBARCH is assumed (not checked) to be a valid Debian |
| 103 | architecture. |
| 104 | |
| 105 | ARCH |
| 106 | -------------------------------------------------- |
| 107 | Set ARCH to the architecture to be built. |
| 108 | In most cases the name of the architecture is the same as the |
| 109 | directory name found in the arch/ directory. |
| 110 | But some architectures such as x86 and sparc have aliases. |
| 111 | x86: i386 for 32 bit, x86_64 for 64 bit |
| 112 | sh: sh for 32 bit, sh64 for 64 bit |
| 113 | sparc: sparc32 for 32 bit, sparc64 for 64 bit |
| 114 | |
| 115 | CROSS_COMPILE |
| 116 | -------------------------------------------------- |
| 117 | Specify an optional fixed part of the binutils filename. |
| 118 | CROSS_COMPILE can be a part of the filename or the full path. |
| 119 | |
| 120 | CROSS_COMPILE is also used for ccache in some setups. |
| 121 | |
| 122 | CF |
| 123 | -------------------------------------------------- |
| 124 | Additional options for sparse. |
| 125 | CF is often used on the command-line like this: |
| 126 | |
| 127 | make CF=-Wbitwise C=2 |
| 128 | |
| 129 | INSTALL_PATH |
| 130 | -------------------------------------------------- |
| 131 | INSTALL_PATH specifies where to place the updated kernel and system map |
| 132 | images. Default is /boot, but you can set it to other values. |
| 133 | |
| 134 | INSTALLKERNEL |
| 135 | -------------------------------------------------- |
| 136 | Install script called when using "make install". |
| 137 | The default name is "installkernel". |
| 138 | |
| 139 | The script will be called with the following arguments: |
| 140 | $1 - kernel version |
| 141 | $2 - kernel image file |
| 142 | $3 - kernel map file |
| 143 | $4 - default install path (use root directory if blank) |
| 144 | |
| 145 | The implementation of "make install" is architecture specific |
| 146 | and it may differ from the above. |
| 147 | |
| 148 | INSTALLKERNEL is provided to enable the possibility to |
| 149 | specify a custom installer when cross compiling a kernel. |
| 150 | |
| 151 | MODLIB |
| 152 | -------------------------------------------------- |
| 153 | Specify where to install modules. |
| 154 | The default value is: |
| 155 | |
| 156 | $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) |
| 157 | |
| 158 | The value can be overridden in which case the default value is ignored. |
| 159 | |
| 160 | INSTALL_MOD_PATH |
| 161 | -------------------------------------------------- |
| 162 | INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory |
| 163 | relocations required by build roots. This is not defined in the |
| 164 | makefile but the argument can be passed to make if needed. |
| 165 | |
| 166 | INSTALL_MOD_STRIP |
| 167 | -------------------------------------------------- |
| 168 | INSTALL_MOD_STRIP, if defined, will cause modules to be |
| 169 | stripped after they are installed. If INSTALL_MOD_STRIP is '1', then |
| 170 | the default option --strip-debug will be used. Otherwise, |
| 171 | INSTALL_MOD_STRIP value will be used as the options to the strip command. |
| 172 | |
| 173 | INSTALL_HDR_PATH |
| 174 | -------------------------------------------------- |
| 175 | INSTALL_HDR_PATH specifies where to install user space headers when |
| 176 | executing "make headers_*". |
| 177 | The default value is: |
| 178 | |
| 179 | $(objtree)/usr |
| 180 | |
| 181 | $(objtree) is the directory where output files are saved. |
| 182 | The output directory is often set using "O=..." on the commandline. |
| 183 | |
| 184 | The value can be overridden in which case the default value is ignored. |
| 185 | |
| 186 | KBUILD_SIGN_PIN |
| 187 | -------------------------------------------------- |
| 188 | This variable allows a passphrase or PIN to be passed to the sign-file |
| 189 | utility when signing kernel modules, if the private key requires such. |
| 190 | |
| 191 | KBUILD_MODPOST_WARN |
| 192 | -------------------------------------------------- |
| 193 | KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined |
| 194 | symbols in the final module linking stage. It changes such errors |
| 195 | into warnings. |
| 196 | |
| 197 | KBUILD_MODPOST_NOFINAL |
| 198 | -------------------------------------------------- |
| 199 | KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. |
| 200 | This is solely useful to speed up test compiles. |
| 201 | |
| 202 | KBUILD_EXTRA_SYMBOLS |
| 203 | -------------------------------------------------- |
| 204 | For modules that use symbols from other modules. |
| 205 | See more details in modules.txt. |
| 206 | |
| 207 | ALLSOURCE_ARCHS |
| 208 | -------------------------------------------------- |
| 209 | For tags/TAGS/cscope targets, you can specify more than one arch |
| 210 | to be included in the databases, separated by blank space. E.g.: |
| 211 | |
| 212 | $ make ALLSOURCE_ARCHS="x86 mips arm" tags |
| 213 | |
| 214 | To get all available archs you can also specify all. E.g.: |
| 215 | |
| 216 | $ make ALLSOURCE_ARCHS=all tags |
| 217 | |
| 218 | KBUILD_ENABLE_EXTRA_GCC_CHECKS |
| 219 | -------------------------------------------------- |
| 220 | If enabled over the make command line with "W=1", it turns on additional |
| 221 | gcc -W... options for more extensive build-time checking. |
| 222 | |
| 223 | KBUILD_BUILD_TIMESTAMP |
| 224 | -------------------------------------------------- |
| 225 | Setting this to a date string overrides the timestamp used in the |
| 226 | UTS_VERSION definition (uname -v in the running kernel). The value has to |
| 227 | be a string that can be passed to date -d. The default value |
| 228 | is the output of the date command at one point during build. |
| 229 | |
| 230 | KBUILD_BUILD_USER, KBUILD_BUILD_HOST |
| 231 | -------------------------------------------------- |
| 232 | These two variables allow to override the user@host string displayed during |
| 233 | boot and in /proc/version. The default value is the output of the commands |
| 234 | whoami and host, respectively. |
| 235 | |
| 236 | KBUILD_LDS |
| 237 | -------------------------------------------------- |
| 238 | The linker script with full path. Assigned by the top-level Makefile. |
| 239 | |
| 240 | KBUILD_VMLINUX_OBJS |
| 241 | -------------------------------------------------- |
| 242 | All object files for vmlinux. They are linked to vmlinux in the same |
| 243 | order as listed in KBUILD_VMLINUX_OBJS. |
| 244 | |
| 245 | KBUILD_VMLINUX_LIBS |
| 246 | -------------------------------------------------- |
| 247 | All .a "lib" files for vmlinux. KBUILD_VMLINUX_OBJS and KBUILD_VMLINUX_LIBS |
| 248 | together specify all the object files used to link vmlinux. |