[U-Boot-Users] Should CRC32 be changed to work against addres s 0 ?
r-woodruff2 at ti.com
Fri Jul 25 18:21:35 CEST 2003
Pretty much as I guessed and I've changed mine. ... However, from my point
of view, as a user I'd rather take the exception when trying to touch zero
as opposed to a wrong answer. I think that most mmu aware systems have
disallowed access to virtual address zero for some time. If the code came
from the embedded space than maybe.
> -----Original Message-----
> From: Wolfgang Denk [mailto:wd at denx.de]
> Sent: Friday, July 25, 2003 11:08 AM
> To: Woodruff, Richard
> Cc: u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] Should CRC32 be changed to work
> against address 0 ?
> Dear Richard,
> in message
> <FD2AC9A020DDD51194710008C7089B200BEE221C at dlee17.itg.ti.com>
> you wrote:
> > CRC32 currently will return 0 if its sent buf address of zero. Is
> > this
> > proper? My ROM is at zero, so running a CRC32 over it might be a
> > useful thing, however, CRC 32 always returns 0 for a start
> address of
> > zero. Is there some reason this needs to be this way? It doesn't
> > seem right to me at first glance.
> The reason is that the CRC32 code was designed to be
> used with user-land applications in a standard OS, where a
> NULL buffer pointer is always an indication of some problem.
> With U-Boot, this is just a bug. Thanks for pointing it out.
> Fixed in my local tree. Will push it to CVS later today.
> Best regards,
> Wolfgang Denk
> Software Engineering: Embedded and Realtime Systems, Embedded Linux
> Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email:
> wd at denx.de ... Jesus cried with a loud voice: Lazarus, come
> forth; the bug hath been found and thy program runneth.
> And he that was dead came
> forth... -- John 11:43-44 [version 2.0?]
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