[PATCH 2/2] env: add CONFIG_ENV_SECT_SIZE_AUTO

[Joakim Tjernlund]

On Wed, 2020-05-06 at 12:15 +0200, Rasmus Villemoes wrote:
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> 
> On 06/05/2020 12.00, Joakim Tjernlund wrote:
> > On Wed, 2020-05-06 at 11:37 +0200, Rasmus Villemoes wrote:
> > > On 06/05/2020 11.21, Joakim Tjernlund wrote:
> > > 
> > > > I can test NOR Flash ,I am on an older u-boot ATM but fw_setenv stuff should be simple to backport
> > > > How would fw_env.config be dealt with? Just ignored when auto size?
> > > 
> > > AFAIK, the U-Boot configuration doesn't affect the userspace fw_env
> > > tools, so auto size has to be opt-in separately in fw_env.config, which
> > > is where I did use 0 to mean auto (see the referenced commit
> > > e282c422e0). You should be able to test that part already with just
> > > fw_setenv built from master and an appropriate fw_env.config [or perhaps
> > > you need to add another "mtdinfo.type == ..." condition first].
> > 
> > Oh, I misunderstood then. I was mostly interested in fw_setenv ATM
> > Looking at your fw_setenv commit I have one question:
> > Will this auto mode also work when erase size < env size ?
> > We have the case:
> > 
> > # MTD device name     Device offset   Env. size       Flash sector size
> >  /dev/mtd1            0x0000          0x2000          0x00001000
> > 
> > Above does not work because EB < Env. size, one have to set the sector size
> > to >= Env. size(0x2000)
> 
> Yes, it should work just fine. My own board has env size 0x2000, so it
> spans two 4K sectors (on the boards with the newer flash). As long as
> one leaves the fifth column (number of sectors) empty or 0, the logic a
> bit further down will automatically compute how many sectors the
> environment occupies.

Nice, got to try your latest fw_setenv patch then :)

> 
> Are you saying that the above config is not accepted by fw_setenv or
> that it causes a run-time error when actually trying to save the env? If
> so, I'd like to see a strace output.

No, I have yet to try your patch. I am saying that
 /dev/mtd1            0x0000          0x2000          0x00001000
in my somewhat older fw_setenv, I think it would silently ignore writing the env. in that case(if I recall correctly)