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

[Dirk Behme <dirk.behme@googlemail.com>]

Hi Stefan,

Stefan Roese wrote:
> Hi Dirk,
> 
> On Saturday 20 June 2009 19:45:40 Dirk Behme wrote:
>> Jean-Christophe PLAGNIOL-VILLARD wrote:
>>>> 2. C++ style comment. Found by Wolfgang ;)
> 
> 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 ;)

>>>> 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=cf96e690cb9840b4a5dc7e750be863228550b5ce
> 
> and 
> 
> http://git.denx.de/?p=u-boot/u-boot-arm.git;a=commit;h=c5ae538c9bd359c137d306e431b2589ba91fbc08
> 
> 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 ;)

> 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.

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?

Many thanks and best regards

Dirk

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