diff options
Diffstat (limited to 'Documentation/kbuild')
| -rw-r--r-- | Documentation/kbuild/kconfig-language.txt | 28 | ||||
| -rw-r--r-- | Documentation/kbuild/kconfig.txt | 66 | ||||
| -rw-r--r-- | Documentation/kbuild/makefiles.txt | 32 | ||||
| -rw-r--r-- | Documentation/kbuild/modules.txt | 2 |
4 files changed, 90 insertions, 38 deletions
diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt index a686f9cd69c..350f733bf2c 100644 --- a/Documentation/kbuild/kconfig-language.txt +++ b/Documentation/kbuild/kconfig-language.txt @@ -147,6 +147,7 @@ applicable everywhere (see syntax). - "modules" This declares the symbol to be used as the MODULES symbol, which enables the third modular state for all config symbols. + At most one symbol may have the "modules" option set. - "env"=<value> This imports the environment variable into Kconfig. It behaves like @@ -156,6 +157,10 @@ applicable everywhere (see syntax). to the build environment (if this is desired, it can be done via another symbol). + - "allnoconfig_y" + This declares the symbol as one that should have the value y when + using "allnoconfig". Used for symbols that hide other symbols. + Menu dependencies ----------------- @@ -388,26 +393,3 @@ config FOO depends on BAR && m limits FOO to module (=m) or disabled (=n). - -Kconfig symbol existence -~~~~~~~~~~~~~~~~~~~~~~~~ -The following two methods produce the same kconfig symbol dependencies -but differ greatly in kconfig symbol existence (production) in the -generated config file. - -case 1: - -config FOO - tristate "about foo" - depends on BAR - -vs. case 2: - -if BAR -config FOO - tristate "about foo" -endif - -In case 1, the symbol FOO will always exist in the config file (given -no other dependencies). In case 2, the symbol FOO will only exist in -the config file if BAR is enabled. diff --git a/Documentation/kbuild/kconfig.txt b/Documentation/kbuild/kconfig.txt index a09f1a6a830..bbc99c0c109 100644 --- a/Documentation/kbuild/kconfig.txt +++ b/Documentation/kbuild/kconfig.txt @@ -20,16 +20,9 @@ symbols have been introduced. To see a list of new config symbols when using "make oldconfig", use cp user/some/old.config .config - yes "" | make oldconfig >conf.new + make listnewconfig -and the config program will list as (NEW) any new symbols that have -unknown values. Of course, the .config file is also updated with -new (default) values, so you can use: - - grep "(NEW)" conf.new - -to see the new config symbols or you can use diffconfig to see the -differences between the previous and new .config files: +and the config program will list any new symbols, one per line. scripts/diffconfig .config.old .config | less @@ -46,6 +39,12 @@ KCONFIG_OVERWRITECONFIG If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not break symlinks when .config is a symlink to somewhere else. +CONFIG_ +-------------------------------------------------- +If you set CONFIG_ in the environment, Kconfig will prefix all symbols +with its value when saving the configuration, instead of using the default, +"CONFIG_". + ______________________________________________________________________ Environment variables for '{allyes/allmod/allno/rand}config' @@ -84,6 +83,42 @@ disable the options that are explicitly listed in the specified mini-config files. ______________________________________________________________________ +Environment variables for 'randconfig' + +KCONFIG_SEED +-------------------------------------------------- +You can set this to the integer value used to seed the RNG, if you want +to somehow debug the behaviour of the kconfig parser/frontends. +If not set, the current time will be used. + +KCONFIG_PROBABILITY +-------------------------------------------------- +This variable can be used to skew the probabilities. This variable can +be unset or empty, or set to three different formats: + KCONFIG_PROBABILITY y:n split y:m:n split + ----------------------------------------------------------------- + unset or empty 50 : 50 33 : 33 : 34 + N N : 100-N N/2 : N/2 : 100-N + [1] N:M N+M : 100-(N+M) N : M : 100-(N+M) + [2] N:M:L N : 100-N M : L : 100-(M+L) + +where N, M and L are integers (in base 10) in the range [0,100], and so +that: + [1] N+M is in the range [0,100] + [2] M+L is in the range [0,100] + +Examples: + KCONFIG_PROBABILITY=10 + 10% of booleans will be set to 'y', 90% to 'n' + 5% of tristates will be set to 'y', 5% to 'm', 90% to 'n' + KCONFIG_PROBABILITY=15:25 + 40% of booleans will be set to 'y', 60% to 'n' + 15% of tristates will be set to 'y', 25% to 'm', 60% to 'n' + KCONFIG_PROBABILITY=10:15:15 + 10% of booleans will be set to 'y', 90% to 'n' + 15% of tristates will be set to 'y', 15% to 'm', 70% to 'n' + +______________________________________________________________________ Environment variables for 'silentoldconfig' KCONFIG_NOSILENTUPDATE @@ -123,7 +158,7 @@ Searching in menuconfig: Example: /hotplug This lists all config symbols that contain "hotplug", - e.g., HOTPLUG, HOTPLUG_CPU, MEMORY_HOTPLUG. + e.g., HOTPLUG_CPU, MEMORY_HOTPLUG. For search help, enter / followed TAB-TAB-TAB (to highlight <Help>) and Enter. This will tell you that you can also use @@ -132,6 +167,17 @@ Searching in menuconfig: /^hotplug + When searching, symbols are sorted thus: + - first, exact matches, sorted alphabetically (an exact match + is when the search matches the complete symbol name); + - then, other matches, sorted alphabetically. + For example: ^ATH.K matches: + ATH5K ATH9K ATH5K_AHB ATH5K_DEBUG [...] ATH6KL ATH6KL_DEBUG + [...] ATH9K_AHB ATH9K_BTCOEX_SUPPORT ATH9K_COMMON [...] + of which only ATH5K and ATH9K match exactly and so are sorted + first (and in alphabetical order), then come all other symbols, + sorted in alphabetical order. + ______________________________________________________________________ User interface options for 'menuconfig' diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 14c3f4f1b61..c600e2f44a6 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -593,7 +593,7 @@ more details, with real examples. Example: #Makefile - LDFLAGS_vmlinux += $(call really-ld-option, -X) + LDFLAGS_vmlinux += $(call ld-option, -X) === 4 Host Program support @@ -921,8 +921,9 @@ When kbuild executes, the following steps are followed (roughly): Often, the KBUILD_CFLAGS variable depends on the configuration. Example: - #arch/x86/Makefile - cflags-$(CONFIG_M386) += -march=i386 + #arch/x86/boot/compressed/Makefile + cflags-$(CONFIG_X86_32) := -march=i386 + cflags-$(CONFIG_X86_64) := -mcmodel=small KBUILD_CFLAGS += $(cflags-y) Many arch Makefiles dynamically run the target C compiler to @@ -1170,7 +1171,7 @@ When kbuild executes, the following steps are followed (roughly): obvious reason. dtc - Create flattend device tree blob object suitable for linking + Create flattened device tree blob object suitable for linking into vmlinux. Device tree blobs linked into vmlinux are placed in an init section in the image. Platform code *must* copy the blob to non-init memory prior to calling unflatten_device_tree(). @@ -1186,6 +1187,29 @@ When kbuild executes, the following steps are followed (roughly): clean-files += *.dtb DTC_FLAGS ?= -p 1024 + dtc_cpp + This is just like dtc as describe above, except that the C pre- + processor is invoked upon the .dtsp file before compiling the result + with dtc. + + In order for build dependencies to work, all files compiled using + dtc_cpp must use the C pre-processor's #include functionality and not + dtc's /include/ functionality. + + Using the C pre-processor allows use of #define to create named + constants. In turn, the #defines will typically appear in a header + file, which may be shared with regular C code. Since the dtc language + represents a data structure rather than code in C syntax, similar + restrictions are placed on a header file included by a device tree + file as for a header file included by an assembly language file. + In particular, the C pre-processor is passed -x assembler-with-cpp, + which sets macro __ASSEMBLY__. __DTS__ is also set. These allow header + files to restrict their content to that compatible with device tree + source. + + A central rule exists to create $(obj)/%.dtb from $(src)/%.dtsp; + architecture Makefiles do no need to explicitly write out that rule. + --- 6.8 Custom kbuild commands When kbuild is executing with KBUILD_VERBOSE=0, then only a shorthand diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt index 69372fb98cf..3fb39e0116b 100644 --- a/Documentation/kbuild/modules.txt +++ b/Documentation/kbuild/modules.txt @@ -470,7 +470,7 @@ build. Sometimes, an external module uses exported symbols from another external module. kbuild needs to have full knowledge of - all symbols to avoid spliitting out warnings about undefined + all symbols to avoid spitting out warnings about undefined symbols. Three solutions exist for this situation. NOTE: The method with a top-level kbuild file is recommended |