[PATCH 4/4] configs: visionfive2: enable SPL_YMODEM_SUPPORT

[E Shattow]

P.S. mis-spoke should have written "Having 'env load' allows to skip
that reboot step
in-between

On Wed, Apr 17, 2024 at 12:28 PM E Shattow <lucent at gmail.com> wrote:
>
> On Wed, Apr 17, 2024 at 1:22 AM Heinrich Schuchardt
> <heinrich.schuchardt at canonical.com> wrote:
> >
> > On 17.04.24 03:41, E Shattow wrote:
> > > Successful in use w/ 'tio' serial tool and Adafruit CP2102N Friend
> > > adapter on Mars CM Lite board in DFRobot mini router carrier.
> > >
> > > While SPL and u-boot.itb payload are sourced via UART the environment
> > > variables are from the environment variable storage as-is. This makes
> > > sense in the use case for development but may have side-effects in the
> > > case of U-Boot as a JH7110 recovery tool. There is now 'env default -f
> > > -a' which does not purge non-default variables and retains the
> > > non-default variables when migrating from vendor firmware. Consider to
> > > also build for U-Boot the commands that can aid in cleaning the stored
> > > environment variable state CONFIG_CMD_ERASEENV=y and in-memory state
> > > CONFIG_CMD_NVEDIT_LOAD=y. With these it can be done easily with: 'env
> > > erase; env load; env save'.
> >
> > Thank you for testing.
> >
> > After erasing there is no need to save the environment. If there is no
> > environment on flash, the default will be loaded anyway:
> >
> >    *** Warning - bad CRC, using default environment
> >
> > Instead of 'env erase' you could use 'sf erase 0xf0000 0x1000' which is
> > already available. As adding CONFIG_CMD_ERASEENV=y is not necessary in
> > the scope of this patch series I would prefer leaving it to future
> > discussion.
> >
> > Best regards
> >
> > Heinrich
> >
>
> The 'env erase; env load; env save' can be done at the same session
> just before recovery write to provide a sanitized environment with the
> defaults of the present U-Boot payload loaded via UART, so is not the
> same as 'sf erase ...' waiting for a reboot (5 minutes more to
> transfer via UART at 115200 baud) and needing to interrupt the boot to
> further 'env save'. Having 'env load' allows to allow that reboot step
> in-between. Point taken though, it's helpful for recovery but not
> required. -E