[U-Boot] suggested/stealable setups for robustness with switchable partitions?

[Robert P. J. Day]

On Mon, 25 Jul 2016, Stefano Babic wrote:

> Hi Robert,
>
> On 25/07/2016 12:42, Robert P. J. Day wrote:

> > p.s. i also noticed a few boards in u-boot that explicitly work with
> > "partition sets":
>
> Do not let be confused by digging the environment into U-Boot. There are
> much more boards as you can discover. In fact, you can see the "default"
> environment, but on many boards the right environment is loaded in
> factory as part of device tests. The default environment, linked with
> u-boot, is not so important for many products.
>
> It is also possible that what you are seeing here is not used at all
> later, and replaced with some other scripts.
>
> Best regards,
> Stefano Babic
>
> >
> > $ grep -r partitionset *
> > board/siemens/taurus/taurus.c:	char *partitionset_active = NULL;
> > board/siemens/taurus/taurus.c:	partitionset_active = getenv("partitionset_active");
> > board/siemens/taurus/taurus.c:	if (partitionset_active) {
> > board/siemens/taurus/taurus.c:		if (partitionset_active[0] == 'A')
> > board/siemens/taurus/taurus.c:			setenv("partitionset_active", "B");
> > board/siemens/taurus/taurus.c:			setenv("partitionset_active", "A");
> > board/siemens/taurus/taurus.c:		printf("partitionset_active missing.\n");
> > include/configs/etamin.h:		"setenv ${partitionset_active} true;" \
> > include/configs/siemens-am33x-common.h:				"setenv ${partitionset_active} true;" \
> > include/configs/siemens-am33x-common.h:					"setenv partitionset_active B; " \
> > include/configs/siemens-am33x-common.h:					"setenv partitionset_active A; " \
> > include/configs/siemens-am33x-common.h:		"echo set ${partitionset_active}...;" \
> > include/configs/siemens-am33x-common.h:	"partitionset_active=A\0" \
> > include/configs/siemens-am33x-common.h:		"echo Set partitionset_active variable to 'A' " \
> > include/configs/siemens-am33x-common.h:		"setenv ${partitionset_active} true;" \
> > include/configs/siemens-am33x-common.h:		"setenv ${partitionset_active} true;" \
> > include/configs/taurus.h:	"partitionset_active=A\0"
> > $

  oh, i understand that, i was just noting another component that can
come into play if someone *wants* to do it as is being done above,
unless it's overridden at the factory.

  a couple more bootlimit/autoboot questions coming later as i try to
pull all this together and finish writing it up, so others don't have
to do as much reading as me. :-)

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================