[U-Boot] [PATCH] mtd: Update MTD infrastructure to support 64bit device size

[Stefan Roese <sr@denx.de>]

On Monday 22 June 2009 20:10:23 Dirk Behme wrote:
> > This is because it's a copy from the Linux code. Not sure if
> > we should change the coding style here. I really prefer to be
> > in sync with the Linux version. This makes future updates easier.
>
> You have to discuss this with Wolfgang, but he wasn't happy about it.
> Enjoy the time while he is on vacation ;)

Yes, will do. ;)

> >>>> 3. The major one: By the new 64bit variables, depending on tool chain,
> >>>> there are now calls to libgcc introduced. Depending on tool chain,
> >>>> this might work, or fail. As it does with one of my tool chains, which
> >>>> worked totally fine until here. It was my understanding that U-Boot
> >>>> shall not rely on libgcc, i.e. proper tool chain libraries.
> >>>>
> >>>> Having CONFIG_SYS_64BIT_VSPRINTF not defined, the linker needs
> >>>> "_lshrdi3", which comes from nand_base.o and nand_bbt.o. E.g. from
> >>>> "len = mtd->size >> (this->bbt_erase_shift + 2);" from nand_bbt.c.
> >>>>
> >>>> Having CONFIG_SYS_64BIT_VSPRINTF enabled, the linker requests
> >>>> _lshrdi3, _udivdi3, _umoddi3 and _clz from libgcc.
> >>>>
> >>>> Looking into U-Boot's lib_arm/ directory, we have already some low
> >>>> level math functions there to avoid libgcc. E.g. nand_bbt.c has
> >>>> references to _ashrdi3, too, but this is resolved by lib_arm's version
> >>>> what is fine.
> >>>>
> >>>> I'd like that NAND code is modified that only math is used which
> >>>> U-Boot provides and no libgcc is needed.
> >>>
> >>> this is a already known problem by Stefan and I and solved
> >>>
> >>> two patchs was send to the ML
> >>
> >> Thanks for the hint! Do you kindly have the subjects or better links
> >> to mailing list archive?
> >
> > http://git.denx.de/?p=u-boot/u-boot-arm.git;a=commit;h=cf96e690cb9840b4a5
> >dc7e750be863228550b5ce
> >
> > and
> >
> > http://git.denx.de/?p=u-boot/u-boot-arm.git;a=commit;h=c5ae538c9bd359c137
> >d306e431b2589ba91fbc08
> >
> > both available in the "testing" branch of u-boot-arm.
>
> Yes, I found them. I was confused because I understood Jean-Christophe
> that they were posted to the list already in the past, and not while
> we were discussing about it ;)

Jean-Christophe did post those patches a few days ago.

> > From you comments on the list I see that you found those patches here
> > too. :)
> >
> > Do these patches fix the building problem for you?
>
> "testing" branch of u-boot-arm compiled fine for me, but I'm not sure
> if the NAND changes are in "testing" branch of u-boot-arm, too.

I'm pretty sure they are, since Jean-Christophe used these patches exactly to 
fix this NAND related problem on ARM. But it should be easy to check if the 
patches are in here. git is your friend... ;)

> Anyway, I would vote for moving these two commits as soon as possible
> into mainline to fix mainline, too. But there was some discussion
> about how to deal with Makefile changes to the patches Jean-Christophe
> sent to the list.
>
> Maybe we can find a solution for the Makefile issues of these patches
> discussed on this list and then move the fixes asap into mainline?

Yes, I would really like to see those changes in mainline soon as well. I have 
to admit that I'm not a real Makefile "expert", so I don't have a real 
expertise to get involved in this discussion. But I'll try to take another 
look at this thread tomorrow.

Thanks.

Best regards,
Stefan

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