1// -*- mode:doc; -*- 2// vim: set syntax=asciidoc: 3 4[[make-tips]] 5=== 'make' tips 6 7This is a collection of tips that help you make the most of Buildroot. 8 9.Display all commands executed by make: 10 11-------------------- 12 $ make V=1 <target> 13-------------------- 14 15.Display the list of boards with a defconfig: 16 17-------------------- 18 $ make list-defconfigs 19-------------------- 20 21.Display all available targets: 22 23-------------------- 24 $ make help 25-------------------- 26 27Not all targets are always available, 28some settings in the +.config+ file may hide some targets: 29 30* +busybox-menuconfig+ only works when +busybox+ is enabled; 31* +linux-menuconfig+ and +linux-savedefconfig+ only work when 32 +linux+ is enabled; 33* +uclibc-menuconfig+ is only available when the uClibc C library is 34 selected in the internal toolchain backend; 35* +barebox-menuconfig+ and +barebox-savedefconfig+ only work when the 36 +barebox+ bootloader is enabled. 37* +uboot-menuconfig+ and +uboot-savedefconfig+ only work when the 38 +U-Boot+ bootloader is enabled. 39 40.Cleaning: 41 42Explicit cleaning is required when any of the architecture or toolchain 43configuration options are changed. 44 45To delete all build products (including build directories, host, staging 46and target trees, the images and the toolchain): 47 48-------------------- 49 $ make clean 50-------------------- 51 52.Generating the manual: 53 54The present manual sources are located in the 'docs/manual' directory. 55To generate the manual: 56 57--------------------------------- 58 $ make manual-clean 59 $ make manual 60--------------------------------- 61 62The manual outputs will be generated in 'output/docs/manual'. 63 64.Notes 65- A few tools are required to build the documentation (see: 66 xref:requirement-optional[]). 67 68.Resetting Buildroot for a new target: 69 70To delete all build products as well as the configuration: 71 72-------------------- 73 $ make distclean 74-------------------- 75 76.Notes 77If +ccache+ is enabled, running +make clean+ or +distclean+ does 78not empty the compiler cache used by Buildroot. To delete it, refer 79to xref:ccache[]. 80 81.Dumping the internal make variables: 82 83One can dump the variables known to make, along with their values: 84 85---- 86 $ make -s printvars VARS='VARIABLE1 VARIABLE2' 87 VARIABLE1=value_of_variable 88 VARIABLE2=value_of_variable 89---- 90 91It is possible to tweak the output using some variables: 92 93- +VARS+ will limit the listing to variables which names match the 94 specified make-patterns - this must be set else nothing is printed 95- +QUOTED_VARS+, if set to +YES+, will single-quote the value 96- +RAW_VARS+, if set to +YES+, will print the unexpanded value 97 98For example: 99 100---- 101 $ make -s printvars VARS=BUSYBOX_%DEPENDENCIES 102 BUSYBOX_DEPENDENCIES=skeleton toolchain 103 BUSYBOX_FINAL_ALL_DEPENDENCIES=skeleton toolchain 104 BUSYBOX_FINAL_DEPENDENCIES=skeleton toolchain 105 BUSYBOX_FINAL_PATCH_DEPENDENCIES= 106 BUSYBOX_RDEPENDENCIES=ncurses util-linux 107---- 108 109---- 110 $ make -s printvars VARS=BUSYBOX_%DEPENDENCIES QUOTED_VARS=YES 111 BUSYBOX_DEPENDENCIES='skeleton toolchain' 112 BUSYBOX_FINAL_ALL_DEPENDENCIES='skeleton toolchain' 113 BUSYBOX_FINAL_DEPENDENCIES='skeleton toolchain' 114 BUSYBOX_FINAL_PATCH_DEPENDENCIES='' 115 BUSYBOX_RDEPENDENCIES='ncurses util-linux' 116---- 117 118---- 119 $ make -s printvars VARS=BUSYBOX_%DEPENDENCIES RAW_VARS=YES 120 BUSYBOX_DEPENDENCIES=skeleton toolchain 121 BUSYBOX_FINAL_ALL_DEPENDENCIES=$(sort $(BUSYBOX_FINAL_DEPENDENCIES) $(BUSYBOX_FINAL_PATCH_DEPENDENCIES)) 122 BUSYBOX_FINAL_DEPENDENCIES=$(sort $(BUSYBOX_DEPENDENCIES)) 123 BUSYBOX_FINAL_PATCH_DEPENDENCIES=$(sort $(BUSYBOX_PATCH_DEPENDENCIES)) 124 BUSYBOX_RDEPENDENCIES=ncurses util-linux 125---- 126 127The output of quoted variables can be reused in shell scripts, for example: 128 129---- 130 $ eval $(make -s printvars VARS=BUSYBOX_DEPENDENCIES QUOTED_VARS=YES) 131 $ echo $BUSYBOX_DEPENDENCIES 132 skeleton toolchain 133---- 134