[PATCH v2 1/3] mx6sabresd: Fix U-Boot corruption after saving the environment

[Igor Opaniuk]

On Fri, Feb 2, 2024 at 9:34 PM Igor Opaniuk <igor.opaniuk at foundries.io> wrote:
>
> On Fri, Feb 2, 2024 at 5:04 PM Fabio Estevam <festevam at gmail.com> wrote:
> >
> > From: Fabio Estevam <festevam at denx.de>
> >
> > U-Boot binary has grown in such a way that it goes beyond the reserved
> > area for the environment variables.
> >
> > Running "saveenv" and rebooting the board causes U-Boot to hang because
> > of this overlap.
> >
> > Fix this problem by selecting CONFIG_LTO so that the U-Boot proper
> > size can be reduced.
> >
> > Also, to prevent this same problem to happen in the future, use
> > CONFIG_BOARD_SIZE_LIMIT, which can detect the overlap in build-time.
> >
> > CONFIG_BOARD_SIZE_LIMIT is calculated as follows:
> >
> > CONFIG_BOARD_SIZE_LIMIT = CONFIG_ENV_OFFSET - u-boot-img.dtb offset
> > CONFIG_BOARD_SIZE_LIMIT = 0xc000 - 69 * 1024
> > CONFIG_BOARD_SIZE_LIMIT = 715766
> >
> > Signed-off-by: Fabio Estevam <festevam at denx.de>
> > ---
> > Changes since v1:
> > - Select LTO. (Tom)
> >
> >  configs/mx6sabresd_defconfig | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/configs/mx6sabresd_defconfig b/configs/mx6sabresd_defconfig
> > index a90efe4a7786..d4fb55622cf1 100644
> > --- a/configs/mx6sabresd_defconfig
> > +++ b/configs/mx6sabresd_defconfig
> > @@ -21,6 +21,9 @@ CONFIG_SPL_SERIAL=y
> >  CONFIG_SPL=y
> >  CONFIG_SPL_LIBDISK_SUPPORT=y
> >  CONFIG_PCI=y
> > +CONFIG_LTO=y
> > +CONFIG_HAS_BOARD_SIZE_LIMIT=y
> > +CONFIG_BOARD_SIZE_LIMIT=715766
> >  CONFIG_FIT=y
> >  CONFIG_SPL_FIT_PRINT=y
> >  CONFIG_SPL_LOAD_FIT=y
> > --
> > 2.34.1
> >
> Reviewed-by: Igor Opaniuk <igor.opaniuk at foundries.io>
>
> btw, from my experience, the same issue will probably occur again in future,
> especially when the current U-Boot size is already close to the defined limit
> (yes, with this patch it will be reported during compile time, but still).
>
> Have you considered adjusting the boot image layout instead
> (moving CONFIG_ENV_OFFSET, so unlikely
> U-Boot image will overlap again) to tackle feature problems?
I've just checked the previous patch version, where
you addressed that exactly with CONFIG_ENV_OFFSET change and
following suggestions/objections from Tom, so sorry for the noise :)

>
> --
> Best regards - Freundliche Grüsse - Meilleures salutations
>
> Igor Opaniuk
> Senior Software Engineer, Embedded & Security
> E: igor.opaniuk at foundries.io
> W: www.foundries.io


-- 
Best regards - Freundliche Grüsse - Meilleures salutations

Igor Opaniuk
Senior Software Engineer, Embedded & Security
E: igor.opaniuk at foundries.io
W: www.foundries.io