[Buildroot] [PATCH] pandaboard_defconfig: bump u-boot to 2015.10 and kernel to 4.3

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

Dear Sergio Prado,

On Thu, 24 Dec 2015 15:33:14 -0200, Sergio Prado wrote:
> VFPv3 and NEON was enabled and a readme.txt file was added.
> 
> Fixes bug #7580.
> 
> Tested on Pandaboard ES.
> 
> Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>

Thanks a lot for this update. I have a number of comments, see below.

> ---
> diff --git a/board/pandaboard/readme.txt b/board/pandaboard/readme.txt
> new file mode 100644
> index 000000000000..7a0e1660c0cb
> --- /dev/null
> +++ b/board/pandaboard/readme.txt
> @@ -0,0 +1,74 @@
> +Pandaboard
> +====================

Nit: excess "=====" signs.

> +
> +This file documents the Buildroot support for the Pandaboard, a
> +low-power, low-cost single-board computer development platform based
> +on the Texas Instruments OMAP4 system on a chip (SoC).
> +
> +

One too many empty new line.

> +Configuring and building Buildroot
> +----------------------------------
> +
> +Start from the defconfig:
> +
> +  $ make pandaboard_defconfig
> +
> +You can edit build options the usual way:
> +
> +  $ make menuconfig
> +
> +When you are happy with the setup, run:
> +
> +  $ make
> +
> +The result of the build with the default settings should be these files:
> +
> +  output/images
> +  ??? MLO
> +  ??? omap4-panda-a4.dtb
> +  ??? omap4-panda.dtb
> +  ??? omap4-panda-es.dtb
> +  ??? rootfs.ext2
> +  ??? u-boot.img
> +  ??? zImage
> +
> +

Ditto.

> +Setting up your SD card
> +-----------------------
> +
> +*Important*: pay attention which partition you are modifying so you don't
> +accidentally erase the wrong file system, e.g your host computer or your
> +external storage!
> +
> +In the default setup you need to create two partitions on your SD card:
> +a boot partition and a rootfs partition.
> +
> +The sdcard needs to be formatted in an specific way. You can use the
> +shell script below to format the sdcard (this script was extracted
> +from http://elinux.org/Panda_How_to_MLO_%26_u-boot).
> +
> +#!/bin/sh
> +if [ ! "$1" = "/dev/sda" ] ; then

I think this check is silly. I know it is in the original script, but
it is still silly.

> +	DRIVE=$1
> +	if [ -b "$DRIVE" ] ; then
> +		dd if=/dev/zero of=$DRIVE bs=1024 count=1024
> +		SIZE=`fdisk -l $DRIVE | grep Disk | awk '{print $5}'`
> +		echo DISK SIZE - $SIZE bytes
> +		CYLINDERS=`echo $SIZE/255/63/512 | bc`
> +		echo CYLINDERS - $CYLINDERS
> +		{
> +		echo ,9,0x0C,*
> +		echo ,,,-
> +		} | sfdisk -D -H 255 -S 63 -C $CYLINDERS $DRIVE
> +		mkfs.vfat -F 32 -n "boot" ${DRIVE}1
> +		mke2fs -j -L "rootfs" ${DRIVE}2
> +	fi
> +fi

Could you instead replace this with a genimage configuration file ? You
can look at the support for the following boards for examples:

./board/via/imx6_vab820/genimage.cfg
./board/intel/galileo/genimage.cfg
./board/wandboard/genimage.cfg

> diff --git a/configs/pandaboard_defconfig b/configs/pandaboard_defconfig
> index 50c3714d84d9..53870b0e1f8d 100644
> --- a/configs/pandaboard_defconfig
> +++ b/configs/pandaboard_defconfig
> @@ -1,39 +1,19 @@
> -# Architecture
>  BR2_arm=y
>  BR2_cortex_a9=y
> -
> -# system
> -BR2_TARGET_GENERIC_GETTY=y
> +BR2_ARM_ENABLE_NEON=y
> +BR2_ARM_FPU_VFPV3=y
>  BR2_TARGET_GENERIC_GETTY_PORT="ttyO2"
> -BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS=y
> -
> -# filesystem
> -BR2_TARGET_ROOTFS_EXT2=y
> -# BR2_TARGET_ROOTFS_TAR is not set
> -
> -# Lock to 3.12 headers to avoid breaking with newer kernels
> -BR2_KERNEL_HEADERS_VERSION=y
> -BR2_DEFAULT_KERNEL_VERSION="3.12.2"
> -BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_3_12=y

You need to keep something like this to lock the kernel headers version
to a version matching the kernel version being used.

> -
> -# Kernel
>  BR2_LINUX_KERNEL=y
> -BR2_LINUX_KERNEL_CUSTOM_VERSION=y
> -BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="3.12.2"

You also need to keep something like this to lock the kernel version
being used. Right now, you're using the "latest" kernel, which is not
what we want, as we want defconfigs to use a fixed kernel and
bootloader version, which have been tested by the submitter of the
defconfig.

>  BR2_LINUX_KERNEL_DEFCONFIG="omap2plus"
> -BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x80008000"
> -BR2_LINUX_KERNEL_APPENDED_UIMAGE=y
> -BR2_LINUX_KERNEL_APPENDED_DTB=y
> -BR2_LINUX_KERNEL_USE_INTREE_DTS=y
> -# might need omap4-panda or omap4-panda-a4 instead
> -BR2_LINUX_KERNEL_INTREE_DTS_NAME="omap4-panda-es"
> -
> -# Bootloaders
> +BR2_LINUX_KERNEL_ZIMAGE=y
> +BR2_LINUX_KERNEL_DTS_SUPPORT=y
> +BR2_LINUX_KERNEL_INTREE_DTS_NAME="omap4-panda-es omap4-panda omap4-panda-a4"
> +BR2_LINUX_KERNEL_INSTALL_TARGET=y
> +BR2_TARGET_ROOTFS_EXT2=y

In your report, you said that the failure was caused by the filesystem
being ext2, but the bootloader trying to mount it as ext3. And now
you're producing an ext2. Is it because the bootloader default kernel
arguments have changed?

> +# BR2_TARGET_ROOTFS_TAR is not set
>  BR2_TARGET_UBOOT=y

You also need to lock the bootloader version, like was done before.

Could you rework those points and submit an updated version?

Thanks a lot!

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