path: root/docs
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authorGravatar Yann E. MORIN <yann.morin.1998@free.fr>2018-08-17 18:06:49 +0200
committerGravatar Thomas Petazzoni <thomas.petazzoni@bootlin.com>2018-08-18 23:21:03 +0200
commite0e089acc491b0f2f97dccaa1c3f6a191873a3b8 (patch)
treee2584b6ef3dc5596203b23ae299150caf2f881e3 /docs
parent9ff4167c8cf94b66a077651b27d796c1a521ac24 (diff)
core/pkg-kconfig: allow dependencies before configurators
Some users of kconfig need some packages to be built before their kconfig infra be used. For example, the linux kernel, starting with 4.16, needs flex and bison to generate the parser code. Furthermore, starting with 4.18, it will also need the cross-compiler before parsing the kconfig stuff, because that calls the compiler to check its features. Currently, this is broken, even the flex/bison ones, even though they are listed, because there is no way to define dependencie that are guaranteed before the (visual) configurators. For example: $ make distclean $ make menuconfig --> enable the linux kernel, choose a defconfig, save, exit $ make linux-menuconfig [...] HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o YACC scripts/kconfig/zconf.tab.c /bin/sh: bison: command not found LEX scripts/kconfig/zconf.lex.c scripts/Makefile.lib:196: recipe for target 'scripts/kconfig/zconf.tab.c' failed make[3]: *** [scripts/kconfig/zconf.tab.c] Error 127 make[3]: *** Waiting for unfinished jobs.... /bin/sh: flex: command not found scripts/Makefile.lib:188: recipe for target 'scripts/kconfig/zconf.lex.c' failed make[3]: *** [scripts/kconfig/zconf.lex.c] Error 127 Makefile:528: recipe for target 'rpc_defconfig' failed make[2]: *** [rpc_defconfig] Error 2 linux/linux.mk:511: recipe for target '/home/ymorin/dev/buildroot/buildroot/output/build/linux-4.17.11/.config' failed make[1]: *** [/home/ymorin/dev/buildroot/buildroot/output/build/linux-4.17.11/.config] Error 2 Makefile:79: recipe for target '_all' failed make: *** [_all] Error 2 So, we introduce a new type of dependencies for kconfig-based packages, that are guaranteed to be built and installed before the (visual) configurators are called. Since those dependencies are phony targets and therefore always out of date, a normal dependency would cause the .config target to be rebuilt on each invocation of make. So we use an order-only pre-requisite, like is done for the patch dependency. Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Cc: Arnout Vandecappelle <arnout@mind.be> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Cc: Jan Kundrát <jan.kundrat@cesnet.cz> Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Diffstat (limited to 'docs')
1 files changed, 4 insertions, 0 deletions
diff --git a/docs/manual/adding-packages-kconfig.txt b/docs/manual/adding-packages-kconfig.txt
index d4d8630a79..982c1229ea 100644
--- a/docs/manual/adding-packages-kconfig.txt
+++ b/docs/manual/adding-packages-kconfig.txt
@@ -81,3 +81,7 @@ be set to suit the needs of the package under consideration:
be well suited for all packages that use the standard kconfig
infrastructure as inherited from the Linux kernel; some packages use
a derivative of kconfig that use a different location.
+* +FOO_KCONFIG_DEPENDENCIES+: the list of packages (most probably, host
+ packages) that need to be built before this package's kconfig is
+ interpreted. Seldom used. By default, empty.