[Buildroot] [PATCH 1/1] configs: beaglebone: update kernel to 4.1.13 and u-boot to 2015.10

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Zoltan,

On Wed, 13 Jan 2016 03:52:22 +0100, Zoltan Gyarmati wrote:

> This patch is basically the cleaned-up version of Chris LaRocque's patch
> from his mail

Thanks for respining this patch.

> "[PATCH 1/2] Updated the Beaglebone configuration, 01/03/2016 10:01 PM"
> and the cleanup followed Arnout's corresponding answers.
> Changes to Chris' patches:
> * dtc patches fetched from GH and placed in 'board/beaglebone/patches/dtc'
> * BR2_GLOBAL_PATCH_DIR set accordingly
> * added seperated kernel defconfig instead of patching the upstream defconfig
> * cleanups in uEnv.txt
> * fix u-boot version to 2015.10
> 
> The heavy-lifting was done by Chris here, the rest is mostly cosmetics. If
> anything els seems to be tweaked, please let us know.
> 
> 
>  board/beaglebone/linux-3.12.config                 |  251 ---
>  board/beaglebone/linux_4.1.13_bb.org_defconfig     | 2043 ++++++++++++++++++++

Looking at its size, this file looks like a full config file and not a
defconfig. Please use a defconfig.

Or better: please use the defconfig that is inside the kernel tree, and
if you need additional tweaks, use config fragments.

>  ...comment-block-of-fdt_get_property_namelen.patch |   32 +
>  .../0002-fdt-Add-a-function-to-count-strings.patch |  246 +++
>  ...d-a-function-to-get-the-index-of-a-string.patch |  159 ++
>  ...004-fdt-Add-functions-to-retrieve-strings.patch |  173 ++

I am not supper happy with the solution of having those DTC patches
specifically for the BeagleBone platform. If I understand correctly,
those patches are needed to get the DT overlay to work, right ?

We had the same problem for the C.H.I.P platform, so it would also be
useful for us to have a overlay-capable DTC. You can see what my
colleague Antoine T?nart did:

  https://github.com/NextThingCo/CHIP-buildroot/commit/1a73b514d204d0c6e9100d53011a11d99fd8b778
  https://github.com/NextThingCo/CHIP-buildroot/commit/f3334df58611ff3cae5fd62906423fdce3d80d24
  https://github.com/NextThingCo/CHIP-buildroot/commit/c4457eba3099f5ca514c06bb35b42772178a151a

It is not ideal because it relies on a separate dtc-overlay package,
which packages a different version of dtc, which Antoine has cooked on
his own github repository.

We really need to find a solution that is acceptable in the upstream
Buildroot, and applies to multiple platforms.

>  ...cache-flush-management-symbols-when-MULTI.patch |   34 -
>  .../0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch   |  754 ++++++++

This huge U-Boot patch is really ugly and mixes lots of stuff. Why do
you need it?


> -# bootloader
>  BR2_TARGET_UBOOT=y
>  BR2_TARGET_UBOOT_BOARDNAME="am335x_evm"
>  BR2_TARGET_UBOOT_CUSTOM_VERSION=y
> -BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2013.10"
> +BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2015.10"
> +BR2_TARGET_UBOOT_NEEDS_DTC=y

So this is going to use the host-dtc package for U-Boot, but isn't the
kernel still going to use its internal copy of dtc ? If so, how are
your dtc patches useful for the kernel ?

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com