[PATCH 1/2] sunxi: allow bigger images for all

[Maxime Ripard]

On Mon, Apr 06, 2020 at 08:24:26PM -0000, Karl Palsson wrote:
>
> Maxime Ripard <maxime at cerno.tech> wrote:
> > Hi,
> >
> > On Mon, Apr 06, 2020 at 03:51:39PM +0000, Karl Palsson wrote:
> > > No reason to limit bigger images to 64bit targets, it's quite easy
> > > to go over the limit with a kernel+initramfs
> >
> > There's a reason: we support some boards with 32 and 64MB of
> > RAM.
> >
> > It would obviously not fit with 32MB boards, and I'm pretty
> > sure it wouldn't with 64MB either.
> >
> > It would make more sense to put that in Kconfig so that boards
> > that need less have a chance at setting a lower limit, just
> > like FASTBOOT_BUF_SIZE
>
> Well, one difference is that the fastboot buffer is memory that's
> _used_ the CONFIG_SYS_BOOTM_LEN is just an artificial limit to
> prevent attempting to boot an image that's "too big" and the limit
> is fairly arbitrary.

There's really no difference with FASTBOOT_BUF_SIZE. It's a limit to
prevent getting an image that's too big, the limit is fairly
arbitrary, and if it's smaller it's not going to use all of it.

> Could it just be removed altogether?

Not really, unfortunately.

> You would "allow" users to run a command that might result in a
> hang/crash

And that's a pretty big deal? Especially since, if you're using a
distro, the kernel size might very well go past the tipping point
without you noticing at all?

> but right now you need to recompile your bootloader based on this
> arbitrary fixed number.
>
> The bootm code already mallocs len * 4, then just artificially
> limits it (or changes the error message) based on this
> CONFIG_SYS_BOOTM_LEN.

Look, I don't really want to argue about this. I gave you a way
forward that would accomodate every one and would allow people with
different expectations to change it to their own arbitrary limit
easily. If you don't want to do it, fine, but this patch is not a
solution either.

Maxime
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