packages build order and dependencies

[Jan Pohanka]

Hello all,

I would like to clarify myself how the order of the package build is
defined. I thought that when I specify the package dependency in
Kconfig, then the top one should be built first. But it seems that I
need also it to add MY_PACKAGE_DEPENDENCIES variable in mk file. Am I right?

Like this example
# Kconfig
config MY_PACKAGE
bool "my_package"
depends on BR2_LINUX_KERNEL


#my_package.mk
...
#is this needed for building linux before my_package?
MY_PACKAGE_DEPENDENCIES += linux
...

best regards
Jan

[Thomas Petazzoni]

Dear Jan Pohanka,

Post by Jan Pohanka
I would like to clarify myself how the order of the package build is
defined. I thought that when I specify the package dependency in
Kconfig, then the top one should be built first. But it seems that I
need also it to add MY_PACKAGE_DEPENDENCIES variable in mk file. Am I right?

What defines the order of build is the <pkg>_DEPENDENCIES variable in
the package .mk file.

Post by Jan Pohanka
Like this example
# Kconfig
config MY_PACKAGE
bool "my_package"
depends on BR2_LINUX_KERNEL

The Config.in stuff doesn't take care of anything build order. It's
just here to ensure consistency of the configuration, i.e that when one
package selects libpng, all packages that can optionally use libpng are
informed and can use it.

Post by Jan Pohanka
#my_package.mk
...
#is this needed for building linux before my_package?
MY_PACKAGE_DEPENDENCIES += linux

Yes, this is precisely what tells Buildroot to build the 'linux'
package, then the 'my-package' package.

Thomas