[PATCH] meta-yocto-bsp: beaglebone: Set a fixed size for boot partition in WIC image

[PATCH] meta-yocto-bsp: beaglebone: Set a fixed size for boot partition in WIC image

[Kevin Hao]

After the dosfstools has been updated to v4.2 by commit b522f24723e1
("dosfstools: update 4.1 -> 4.2"), the commit b29eb5be67e9 ("mkfs.fat:
Align total number of sectors to be multiple of sectors per track") in
v4.2 has caused a regression in beagebone black board. The reason is
that the real total sectors of the fat filesystem created by the mkdosfs
may not be the same size as what we requested due to align with the
sectors per track, this change seem no side effect to linux kernel,
but it breaks the beaglebone black boot ROM and make it can't load the
MLO. In order to fix this issue, we choose to set a fixed size for the
boot partition to make sure that the total sectors always are aligned
with the sectors per track.

[Yocto #14306]

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
---
 meta-yocto-bsp/wic/beaglebone-yocto.wks | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta-yocto-bsp/wic/beaglebone-yocto.wks b/meta-yocto-bsp/wic/beaglebone-yocto.wks
index 701ae0b3d4bd..7a28fb23dc89 100644
--- a/meta-yocto-bsp/wic/beaglebone-yocto.wks
+++ b/meta-yocto-bsp/wic/beaglebone-yocto.wks
@@ -2,6 +2,6 @@
 # long-description: Creates a partitioned SD card image for Beaglebone.
 # Boot files are located in the first vfat partition.
 
-part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --size 16 --sourceparams="loader=u-boot" --use-uuid
+part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --fixed-size 32 --sourceparams="loader=u-boot" --use-uuid
 part / --source rootfs --ondisk mmcblk0 --fstype=ext4 --label root --align 4 --use-uuid
 bootloader --append="console=ttyS0,115200"
-- 
2.30.2

Re: [poky] [PATCH] meta-yocto-bsp: beaglebone: Set a fixed size for boot partition in WIC image

[Denys Dmytriyenko]

On Tue, Mar 23, 2021 at 05:35:29PM +0800, Kevin Hao wrote:
> After the dosfstools has been updated to v4.2 by commit b522f24723e1
> ("dosfstools: update 4.1 -> 4.2"), the commit b29eb5be67e9 ("mkfs.fat:
> Align total number of sectors to be multiple of sectors per track") in
> v4.2 has caused a regression in beagebone black board. The reason is
> that the real total sectors of the fat filesystem created by the mkdosfs
> may not be the same size as what we requested due to align with the
> sectors per track, this change seem no side effect to linux kernel,
> but it breaks the beaglebone black boot ROM and make it can't load the
> MLO. In order to fix this issue, we choose to set a fixed size for the
> boot partition to make sure that the total sectors always are aligned
> with the sectors per track.

Thanks for getting to the root cause of the failure!
Yeah, embedded boot ROM is not very flexible and has rather simplistic 
understanding of FAT.

-- 
Denys


> [Yocto #14306]
> 
> Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
> ---
>  meta-yocto-bsp/wic/beaglebone-yocto.wks | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/meta-yocto-bsp/wic/beaglebone-yocto.wks b/meta-yocto-bsp/wic/beaglebone-yocto.wks
> index 701ae0b3d4bd..7a28fb23dc89 100644
> --- a/meta-yocto-bsp/wic/beaglebone-yocto.wks
> +++ b/meta-yocto-bsp/wic/beaglebone-yocto.wks
> @@ -2,6 +2,6 @@
>  # long-description: Creates a partitioned SD card image for Beaglebone.
>  # Boot files are located in the first vfat partition.
>  
> -part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --size 16 --sourceparams="loader=u-boot" --use-uuid
> +part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --fixed-size 32 --sourceparams="loader=u-boot" --use-uuid
>  part / --source rootfs --ondisk mmcblk0 --fstype=ext4 --label root --align 4 --use-uuid
>  bootloader --append="console=ttyS0,115200"
> -- 
> 2.30.2