[Buildroot] [PATCHv3] beaglebone: add BeagleBone Black support

Tue Oct 15 01:57:58 UTC 2013

On Mon, Oct 14, 2013 at 6:39 PM, Arnout Vandecappelle <arnout at mind.be> wrote:
>  Hi Jason,
>
>
> On 11/10/13 22:09, Jason Kridner wrote:
>>
>> From: Jason Kridner <jdk at ti.com>
>>
>> * Update BeagleBone to 3.8.13-beagleboard kernel
>> * Update to u-boot 2013.07
>> * Add BeagleBone Black device tree
>> * Remove M3 firmware loading until debugged
>> * Remove BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS because it is the
>> default
>>
>> Just to make sure this is documented well, here are the steps I used to
>> test
>> the output images:
>
>
>  This kind of information should go into board/beaglebone/readme.txt.

k.

>
>>   # gzip rootfs.ext2
>
>
>  If you set BR2_TARGET_ROOTFS_EXT2_GZIP you don't need to do this.
>
>  However, using ext2 for a ramdisk image is horribly inefficient. You'd
> normally use a cpio image. Also, lzma (smaller size) or lzop (larger but
> faster uncompression) are better choices than gzip.

I thought I had pushback on using initramfs, which is what I'd prefer
to have as the default. I'm simply trying to minimize the patch to get
Black in there in the defaults.

>
>
>>   # mkimage -A arm -O linux -T ramdisk -C gzip -a 0x81000000 -d
>> rootfs.ext2.gz ramdisk.gz
>
>
>  Ideally, you should make a post-image script (BR2_ROOTFS_POST_IMAGE_SCRIPT)
> in the board/beaglebone directory that does these steps automatically. And
> since this script uses mkimage, I'd also explicitly enable
> BR2_PACKAGE_HOST_UBOOT_TOOLS (even though it is implicitly build for the
> kernel uImage).

Thanks for pointing this out and I'll certainly make personal use of
it. I'm doubtful if including it would help get my patch accepted.

>
>
>>   # The URL is where I stored the ouptut of 'make beaglebone_defconfig;
>> make'
>>   $ wget -r
>> https://s3.amazonaws.com/beagle/buildroot/2013-10-11-16%3A52%3A21/index.html
>>   $ cd s3.amazonaws.com/beagle/buildroot/2013-10-11-16:52:21
>>   $ cat >uEnv.txt <<EOF
>>   bootpart=0:1
>>   bootdir=
>>   uenvcmd=run loaduimage;run loadramdisk;run findfdt;run loadfdt;run
>> ramboot
>>   EOF
>
>
>  You can add uEnv.txt to board/beaglebone and copy it to images/ in the
> post-image script.

k, but again, I'm not sure if it is desired upstream. If I add it to
v4, will it get accepted?

>
>
>>   # With /mnt being a FAT formatted uSD card with partition marked as
>> bootable
>>   $ cp MLO u-boot.img uImage ramdisk.gz uEnv.txt *.dtb /mnt
>>   # eject /mnt
>>   # Insert uSD card into BeagleBone Black
>>   # Hold "BOOT" button
>>   # Apply power and release "BOOT" button
>>   # Serial log at screenlog.0
>
>
>  With the post-image script, the readme can be limited to these 7 lines :-)
>
>
>>
>> Ideally for me, I'd switch to an initramfs and patch u-boot to avoid
>> uEnv.txt,
>> but I'll do that separately.
>
>
>  I'm not a fan of initramfs because every rootfs change requires a slow
> re-link of the kernel... And I don't see the harm in uEnv.txt.

k, but you want a cpio image instead of a ramdisk? I guess I'll take a
look at how to use a cpio image as an initrd.

What I'd like to know is what will be accepted upstream. I feel like I
am wasting my time right switching approaches that don't have that
much to do with BeagleBone Black when what I most fundamentally want
to introduce is a pointer to a different kernel and the combination of
.dtb files for BeagleBone and BeagleBone Black.

>
>
>>
>> Changes since v2
>> (http://lists.busybox.net/pipermail/buildroot/2013-September/079136.html):
>
>
>  The patch changelog should be preceded by --- (on a line by itself). This
> separator tells git that what follows it doesn't have to be included in the
> commit log.
>
>
>> * Moved back to ext2/ramdisk and eliminated u-boot customizations
>> * Removed host tool customizations
>>
>> Changes since v1
>> (http://lists.busybox.net/pipermail/buildroot/2013-September/079046.html):
>> * Added BeagleBone Black to single config for BeagleBone and BeagleBone
>> Black,
>>    rather than having two configs
>> * Used 'make ARCH=arm savedefconfig' to create Linux config file
>> * Dropped setting of DEVTMPFS, since it is default now
>> * Switched to u-boot 2013.07 from 2013.04
>> * Patched u-boot to work with initramfs by default without uEnv.txt
>> * Removed wake-up M3 firmware loading for now, until debugged
>>
>> Signed-off-by: Jason Kridner <jdk at ti.com>
>
>
>  The Signoff line should of course come before the ---

k

>
>
>> ---
>>   board/beaglebone/linux-3.8.config | 1035
>> ++++++++++++++++++++++++++++++++++---
>>   configs/beaglebone_defconfig      |   13 +-
>>   2 files changed, 975 insertions(+), 73 deletions(-)
>>
>> diff --git a/board/beaglebone/linux-3.8.config
>> b/board/beaglebone/linux-3.8.config
>> index 4242771..08ab221 100644
>> --- a/board/beaglebone/linux-3.8.config
>> +++ b/board/beaglebone/linux-3.8.config
>> @@ -1,103 +1,409 @@
>>   CONFIG_EXPERIMENTAL=y
>> -CONFIG_DEFAULT_HOSTNAME="beaglebone"
>> +CONFIG_KERNEL_LZO=y
>>   CONFIG_SYSVIPC=y
>>   CONFIG_POSIX_MQUEUE=y
>>   CONFIG_NO_HZ=y
>>   CONFIG_HIGH_RES_TIMERS=y
>>   CONFIG_BSD_PROCESS_ACCT=y
>> +CONFIG_BSD_PROCESS_ACCT_V3=y
>> +CONFIG_TASKSTATS=y
>> +CONFIG_TASK_DELAY_ACCT=y
>> +CONFIG_TASK_XACCT=y
>> +CONFIG_TASK_IO_ACCOUNTING=y
>
>
>  You're adding a lot of kernel features here that were not enabled before.
> We generally prefer the kernel configs to be pretty minimal (except that all
> drivers for hardware that is present on the board should be included, of
> course. What's the history of this kernel config? You don't mention it at
> all in the commit message.

This comes from the kernel config we use in the demo image shipped
with the boards.

https://github.com/beagleboard/kernel/commits/3.8/configs/beaglebone

Should I include a link like this?

I can use something more minimal, but the idea was to try to provide
something that showed off as much capability as possible. I'll see
what I can cut out.

>
>
>>   CONFIG_IKCONFIG=y
>>   CONFIG_IKCONFIG_PROC=y
>> -CONFIG_LOG_BUF_SHIFT=16
>> +CONFIG_CGROUP_CPUACCT=y
>> +CONFIG_RESOURCE_COUNTERS=y
>> +CONFIG_MEMCG=y
>> +CONFIG_BLK_CGROUP=y
>> +CONFIG_NAMESPACES=y
>> +CONFIG_SCHED_AUTOGROUP=y
>>   CONFIG_BLK_DEV_INITRD=y
>>   CONFIG_CC_OPTIMIZE_FOR_SIZE=y
>> -CONFIG_EMBEDDED=y
>> +CONFIG_EXPERT=y
>> +CONFIG_KALLSYMS_ALL=y
>>   CONFIG_SLAB=y
>>   CONFIG_PROFILING=y
>>   CONFIG_OPROFILE=m
>> -CONFIG_KPROBES=y
>>   CONFIG_MODULES=y
>>   CONFIG_MODULE_FORCE_LOAD=y
>>   CONFIG_MODULE_UNLOAD=y
>>   CONFIG_MODULE_FORCE_UNLOAD=y
>>   CONFIG_MODVERSIONS=y
>> -# CONFIG_BLK_DEV_BSG is not set
>> +CONFIG_MODULE_SRCVERSION_ALL=y
>> +CONFIG_BLK_DEV_BSGLIB=y
>> +CONFIG_BLK_DEV_INTEGRITY=y
>> +CONFIG_PARTITION_ADVANCED=y
>> +CONFIG_MAC_PARTITION=y
>>   CONFIG_ARCH_OMAP=y
>>   CONFIG_OMAP_RESET_CLOCKS=y
>>   CONFIG_OMAP_MUX_DEBUG=y
>> +CONFIG_OMAP_MBOX_FWK=y
>> +CONFIG_OMAP_32K_TIMER_HZ=512
>>   # CONFIG_ARCH_OMAP2 is not set
>> -# CONFIG_ARCH_OMAP3 is not set
>> -# CONFIG_ARCH_OMAP4 is not set
>> +# CONFIG_SOC_TI81XX is not set
>> +# CONFIG_MACH_DEVKIT8000 is not set
>> +# CONFIG_MACH_OMAP_LDP is not set
>> +# CONFIG_MACH_OMAP3530_LV_SOM is not set
>> +# CONFIG_MACH_OMAP3_TORPEDO is not set
>> +# CONFIG_MACH_OVERO is not set
>> +# CONFIG_MACH_OMAP3EVM is not set
>> +# CONFIG_MACH_OMAP3517EVM is not set
>> +# CONFIG_MACH_OMAP3_PANDORA is not set
>> +# CONFIG_MACH_TOUCHBOOK is not set
>> +# CONFIG_MACH_OMAP_3430SDP is not set
>> +# CONFIG_MACH_NOKIA_RM680 is not set
>> +# CONFIG_MACH_NOKIA_RX51 is not set
>> +# CONFIG_MACH_OMAP_ZOOM2 is not set
>> +# CONFIG_MACH_OMAP_ZOOM3 is not set
>> +# CONFIG_MACH_CM_T35 is not set
>> +# CONFIG_MACH_CM_T3517 is not set
>> +# CONFIG_MACH_IGEP0030 is not set
>> +# CONFIG_MACH_SBC3530 is not set
>> +# CONFIG_MACH_OMAP_3630SDP is not set
>> +# CONFIG_MACH_OMAP_4430SDP is not set
>>   CONFIG_ARM_THUMBEE=y
>> -CONFIG_ARM_ERRATA_720789=y
>> -CONFIG_ARM_ARCH_TIMER=y
>> +CONFIG_SMP=y
>
>
>  SMP???

Good point.

>
>
>> +CONFIG_PREEMPT_VOLUNTARY=y
>> +CONFIG_THUMB2_KERNEL=y
>> +# CONFIG_COMPACTION is not set
>>   CONFIG_ZBOOT_ROM_TEXT=0x0
>>   CONFIG_ZBOOT_ROM_BSS=0x0
>> -CONFIG_CMDLINE="root=/dev/mmcblk0p2 rootwait console=ttyO2,115200"
>> -CONFIG_KEXEC=y
>> -CONFIG_AUTO_ZRELADDR=y
>> +CONFIG_ARM_APPENDED_DTB=y
>
>
>  You're not using appended DTB, right?

True.

>
>> +CONFIG_ARM_ATAG_DTB_COMPAT=y
>>   CONFIG_CPU_FREQ=y
>
> [snip a lot of deviations from defaults]
>>
>> +CONFIG_MTD=y
>
>
>  Beaglebones don't even have any flash, right?

They have eMMC, which isn't the same as MTD, so, right, there isn't
any MTD flash built-in. However, with add-on board it is possible to
add it. Many of the things added are for being able to support add-on
boards.

>
>
>> +CONFIG_MTD_CMDLINE_PARTS=y
>> +CONFIG_MTD_CHAR=y
>> +CONFIG_MTD_BLOCK=y
>> +CONFIG_MTD_CFI=y
>> +CONFIG_MTD_CFI_INTELEXT=y
>> +CONFIG_MTD_NAND=y
>> +CONFIG_MTD_NAND_OMAP2=y
>> +CONFIG_MTD_ONENAND=y
>> +CONFIG_MTD_ONENAND_VERIFY_WRITE=y
>> +CONFIG_MTD_ONENAND_OMAP2=y
>> +CONFIG_MTD_UBI=y
>> +CONFIG_MTD_UBI_FASTMAP=y
>
> [snip more fatness]
>>
>> +CONFIG_MEDIA_USB_SUPPORT=y
>
>
>  Yeah, for USB devices you could consider that it's always possible to plug
> them in, but most of them are anyway useless without any userspace
> support... I would keep mass storage and vfat, though.

Agree there are many that simply don't have the userspace support. I'll trim.

Note: I haven't included the cape firmware .dtbo files that are needed
for those. It is a good TODO to add those.

>
> [snip 100s of modules]
>
>>   CONFIG_EXT2_FS=y
>>   CONFIG_EXT3_FS=y
>>   # CONFIG_EXT3_FS_XATTR is not set
>>   CONFIG_EXT4_FS=y
>> +CONFIG_REISERFS_FS=m
>
>
>  Keeping all possible extfses makes sense, but all the rest should go IMHO.
> Perhaps NFS can stay.

k. I'll avoid the '+' on the file systems that aren't likely to be
used. FUSE is the only one I might try to defend.

>
>
>> +CONFIG_JFS_FS=m
>> +CONFIG_XFS_FS=m
>> +CONFIG_XFS_QUOTA=y
>> +CONFIG_XFS_POSIX_ACL=y
>> +CONFIG_XFS_RT=y
>> +CONFIG_GFS2_FS=m
>> +CONFIG_BTRFS_FS=m
>> +CONFIG_NILFS2_FS=m
>> +CONFIG_FANOTIFY=y
>> +CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
>>   CONFIG_QUOTA=y
>>   CONFIG_QFMT_V2=y
>> +CONFIG_AUTOFS4_FS=m
>> +CONFIG_FUSE_FS=m
>> +CONFIG_CUSE=m
>>   CONFIG_MSDOS_FS=y
>>   CONFIG_VFAT_FS=y
>>   CONFIG_TMPFS=y
>> -# CONFIG_MISC_FILESYSTEMS is not set
>> +CONFIG_TMPFS_POSIX_ACL=y
>> +CONFIG_JFFS2_FS=y
>
>
>  Definitely flash filesystems shouldn't be there.

k. If flash add-on board support isn't needed, I'll leave the added
flash file systems out.

>
> [snip]
>
>> diff --git a/configs/beaglebone_defconfig b/configs/beaglebone_defconfig
>> index d6b5c31..47cd0c4 100644
>> --- a/configs/beaglebone_defconfig
>> +++ b/configs/beaglebone_defconfig
>> @@ -5,24 +5,22 @@ BR2_ARM_EABIHF=y
>>
>>   # system
>>   BR2_TARGET_GENERIC_HOSTNAME="beaglebone"
>> -BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS=y
>>   BR2_TARGET_GENERIC_GETTY_PORT="ttyO0"
>>   # BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
>>
>>   # filesystem
>> -BR2_PACKAGE_AM33X_CM3=y
>
>
>  We normally don't keep things in comments, but here I think it makes sense
> to keep this package in a comment and mention that it is not included for
> the time being due to instability. That will invite a future version bumper
> to re-include it.

k.

>
>
>  Sorry for the large number of comments so long after you posted the
> patch...
>
>
>  Regards,
>  Arnout
>
>
>>   BR2_TARGET_ROOTFS_EXT2=y
>>   # BR2_TARGET_ROOTFS_TAR is not set
>>
>>   # lock down headers to avoid breaking with new defaults
>>   BR2_KERNEL_HEADERS_VERSION=y
>> -BR2_DEFAULT_KERNEL_VERSION="3.8.12"
>> +BR2_DEFAULT_KERNEL_VERSION="3.8.13"
>>
>>   # bootloader
>>   BR2_TARGET_UBOOT=y
>>   BR2_TARGET_UBOOT_BOARDNAME="am335x_evm"
>>   BR2_TARGET_UBOOT_CUSTOM_VERSION=y
>> -BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2013.04"
>> +BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2013.07"
>>   BR2_TARGET_UBOOT_FORMAT_IMG=y
>>   BR2_TARGET_UBOOT_SPL=y
>>   BR2_TARGET_UBOOT_SPL_NAME="MLO"
>> @@ -30,9 +28,10 @@ BR2_TARGET_UBOOT_SPL_NAME="MLO"
>>   # kernel
>>   BR2_LINUX_KERNEL=y
>>   BR2_LINUX_KERNEL_CUSTOM_GIT=y
>>
>> -BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL="git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git"
>>
>> -BR2_LINUX_KERNEL_CUSTOM_GIT_VERSION="935f6c2f82056d538b528272e2bdbb5c08d69a58"
>>
>> +BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL="git://github.com/beagleboard/linux.git"
>>
>> +BR2_LINUX_KERNEL_CUSTOM_GIT_VERSION="ddd36e546e53d3c493075bbebd6188ee843208f9"
>>   BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
>>   BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/beaglebone/linux-3.8.config"
>>   BR2_LINUX_KERNEL_DTS_SUPPORT=y
>> -BR2_LINUX_KERNEL_INTREE_DTS_NAME="am335x-bone"
>> +BR2_LINUX_KERNEL_USE_INTREE_DTS=y
>> +BR2_LINUX_KERNEL_INTREE_DTS_NAME="am335x-bone am335x-boneblack"
>>
>
>
> --
> Arnout Vandecappelle                          arnout at mind be
> Senior Embedded Software Architect            +32-16-286500
> Essensium/Mind                                http://www.mind.be
> G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
> LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
> GPG fingerprint:  7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F