[U-Boot] [PATCH v3 3/3] config: Remove Blackfin CONFIG_DEPRECATED_SILENT_LINUX_CONSOLE

Doug Anderson dianders at chromium.org
Wed Jan 11 19:22:47 CET 2012


Dear Wolfgang,

On Wed, Jan 11, 2012 at 12:11 AM, Wolfgang Denk <wd at denx.de> wrote:
> I have to admit that I have no clear opinion here yet.
>
> The existing code is from a time when all architectures had a pretty
> low limit on the command line size - IIRC even PPC had only 256 bytes
> by then, hard coded.
>
> I think we have two options:
>
> 1) Try not to exceed any limits imposed by the Linux kernel.
>   Advantage: we can catch situations where the user overflows the
>           limits and print an error message (IIRC this needs to be
>           added), so the user gets aware of the pronlem.
>   Disadvantage: we need to add architecture specific definitions for
>           the command line size, and keep these in sync with any
>           related changes to the Linux kernel.  We know in advance
>           that this will not work really well.
>
> 2) We just make sure not to overwrite array bounds in U-Boot, and
>   allow passing arbitrary sized buffers to the Linux kernel.
>   Advantage: the code in U-Boot can be simple and clean
>   Disadvantage: the resulting behaviour is not exactly user-friendly,
>           as a silent truncation in the Linux kernel is probably hard
>           to spot.
>
> Hm...
>
> I agree that the old code needs fixing.  I think it would be nice if
> we could adapt U-Boot behaviour, but I fear that actually it cannot
> work at all, as we don't know which Linux kernel version the user will
> use, and what their limits might be.
>
> So in the end 2) is probably the most sensible approach here.

Thank you for all of your time on this issue.  I have just sent a
patch implementing 2) with as little extra cruft as possible (I hope).
 Let me know if there is anything else you need here.  Thanks!

-Doug


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