[Buildroot] [PATCH 14/55] documentation: Update to explain how board support works
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Sat Dec 11 10:05:39 UTC 2010
Steve,
On Fri, 10 Dec 2010 20:37:57 -0800 (PST)
Steve Calfee <nospamcalfee at yahoo.com> wrote:
> I am trying to prepare a board support package. I have run this step
> and stuff disappeared from the .config, for instance:
When you run "savedefconfig", it generates a defconfig file that
contains the value only for the config options that are not of the
default value, and that cannot be computed from other options.
> BR2_ARM_TYPE="ARM926T"
This is an hidden option, whose value is selected depending on
BR2_arm926t. So if you have BR2_arm926t=y in your defconfig, having
BR2_ARM_TYPE="ARM926T" is useless: it will be computed automatically.
> BR2_ARM_EABI=y
This is the default.
> # BR2_ARM_OABI is not set
This is the default.
> BR2_ARCH="arm"
> BR2_ENDIAN="LITTLE"
> BR2_GCC_TARGET_TUNE="arm926ej-s"
> BR2_GCC_TARGET_ARCH="armv5te"
> BR2_GCC_TARGET_ABI="aapcs-linux"
All those are hidden options, whose value is computed from the value of
other options, so there's no need to store them in defconfig files.
> Is this normal? It takes so long to completely rebuild, but they
> don't seem to matter. If you say savedefconfig is enough, ok with me.
savedefconfig is enough. For all options that you were wondering about,
having:
BR2_arm=y
BR2_arm926t=y
in your savedefconfig is sufficient.
Regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
More information about the buildroot
mailing list