U-Boot customization: Using mainline or follow eewiki.net and apply patches ? Differences ?

Sylvain_Lamontagne · January 17, 2017, 12:03am

Hi,

We use the BeagleBone Green and I need to make some customization to U-Boot to make sure phantom characters would not stop the BeagleBone from booting.
I have experience in creating custom boards in U-Boot and generally I could have fix this simple phantom character problem by simply saving the proper bootdelay environment variables in U-Boot during the manufacturing process. But, the BeagleBone Black/Green use a uEnv.txt file for the environment variables and it cannot be used for bootdelay. So, I need to customize the default environments.

I know how to do all that, my question is: Should I use U-Boot mainline (https://github.com/u-boot/u-boot/tree/v2017.01) or do I absolutely need to follow eewiki.net (https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-Bootloader:U-Boot) and apply the patches listed there before starting the customization ?

What are the differences between mainline and eewiki’s patched version ?

Thank you

Sylvain Lamontagne

RobertCNelson · January 17, 2017, 12:41am

Hi,

We use the BeagleBone Green and I need to make some customization to U-Boot
to make sure phantom characters would not stop the BeagleBone from booting.

That's this 4 line change..

github.com

RobertCNelson/Bootloader-Builder/blob/master/patches/v2017.01/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch#L821-L824


      
          From 37f37a09b3c8e14ba7ca3fd1eb7e7e2a6c95bc0f Mon Sep 17 00:00:00 2001
          From: Robert Nelson <robertcnelson@gmail.com>
          Date: Thu, 26 Jan 2017 15:39:05 -0600
          Subject: [PATCH] am335x_evm: uEnv.txt, bootz, n fixes
          
          Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
          ---
           board/ti/am335x/board.c            |  43 +++++-
           board/ti/am335x/board.h            |  20 +++
           board/ti/am335x/mux.c              |   9 +-
           configs/am335x_boneblack_defconfig |   2 +-
           configs/am335x_evm_defconfig       |  23 ++--
           include/configs/am335x_evm.h       |  60 ++++++--
           include/configs/ti_armv7_common.h  | 276 +++++++++++++++++++++++++++++++++++--
           scripts/config_whitelist.txt       |   1 +
           8 files changed, 394 insertions(+), 40 deletions(-)
          
          diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
          index 8eaf3e9a5c..cde6c3ba32 100644
          --- a/board/ti/am335x/board.c

This file has been truncated. show original

We pushed it mainline, lasted about two releases before a later change
disabled it.

I have experience in creating custom boards in U-Boot and generally I could
have fix this simple phantom character problem by simply saving the proper
bootdelay environment variables in U-Boot during the manufacturing process.
But, the BeagleBone Black/Green use a uEnv.txt file for the environment
variables and it cannot be used for bootdelay. So, I need to customize the
default environments.

I know how to do all that, my question is: Should I use U-Boot mainline
(GitHub - u-boot/u-boot at v2017.01) or do I absolutely need to
follow eewiki.net
(https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-Bootloader:U-Boot)
and apply the patches listed there before starting the customization ?

What are the differences between mainline and eewiki's patched version ?

Most of our patchset is to support 'stuff' we came up with before
extlinux/distro_defaults went into u-boot mainline.

Then we have support for board's in flight.. BeagleBone Green
Wireless/BeagleBone Black Wireless, when those dts files get merged
into linus' master tree for v4.11.0-rc1 i'll push them to u-boot
master.. (they are staged in linux-omap right now)

Then lots of "debug" enablement, from when we chased fun bugs..

Regards,