[U-Boot] [U-Boot,v2] spl: implement CRC check on U-Boot uImage

[Simon Goldschmidt]

On Fri, Feb 8, 2019 at 10:20 PM Tom Rini <trini at konsulko.com> wrote:
>
> On Fri, Feb 08, 2019 at 10:05:41PM +0100, Simon Goldschmidt wrote:
> > On Fri, Feb 8, 2019 at 8:46 PM Tom Rini <trini at konsulko.com> wrote:
> > >
> > > On Wed, Nov 28, 2018 at 09:52:45PM +0100, Simon Goldschmidt wrote:
> > >
> > > > SPL currently does not check uImage CRCs when loading U-Boot.
> > > >
> > > > This patch adds checking the uImage CRC when SPL loads U-Boot. It does
> > > > this by reusing the existing config option SPL_CRC32_SUPPORT to allow
> > > > leaving out the CRC check on boards where the additional code size or
> > > > boot time is a problem (adding the CRC check currently adds ~1.4 kByte
> > > > to flash).
> > > >
> > > > The SPL_CRC32_SUPPORT config option now gets enabled by default if SPL
> > > > support for legacy images is enabled to check the CRC on all boards
> > > > that don't actively take countermeasures.
> > > >
> > > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
> > > > Reviewed-by: Simon Glass <sjg at chromium.org>
> > >
> > > Really sorry for the delay on this, especially as I've found one or two
> > > problems.  The first problem is that with this vyasa-rk3288 and a few
> > > others fail to build due to a number of errors such as:
> > > ../common/spl/spl.c:269:12: error: 'struct spl_image_info' has no member
> > > named 'dcrc_data'
> >
> > Hmm, let me check what's wrong there.

OK, so the vyasa-rk3288 uses TPL, that's what I got wrong.

> > >
> > > Second, I believe this is causing a number of platforms with very tight
> > > SPL constraints, namely all of 64bit sunxi, to fail to link as they
> > > overflow SRAM now.  This can be fixed at least by making the new
> > > behavior opt-in, but I would fix the vyasa-rk3288 problem first.  Thanks
> > > in advance!
> >
> > Well, I thought it would be better to have it default to 'y' since I think it
> > is what is expected. Shouldn't we explicitly work on those platforms?
> > I must say I was pretty shocked to see that SPL did not detect an invalid
> > CRC...
> >
> > Can you point me to a config that fails?
>
> In general, pine64_plus_defconfig is one that might (as I re-run my
> build without this patch, I still see some failures but they've scrolled
> off screen, but 64bit sunxi _is_ very sensitive to SPL growth).

And I also did compile that one but I don't see any error message. How
am I supposed to detect the SRAM overflowing?

I assume it's .text or .rodata which makes it grow too big? If so, we could
still check the CRC by using a smaller algorithm that does not rely on a
precalculated table...

Regards,
Simon