From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?UTF-8?B?Q2zDqW1lbnQgUMOpcm9u?= <peron.clem@gmail.com>
Date: Mon, 5 Nov 2018 17:44:40 +0100
Subject: [U-Boot] [PATCH v3 10/26] fs: fat: support write with non-zero
	offset
In-Reply-To: <20181101051118.GM11663@linaro.org>
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To: u-boot@lists.denx.de

Hi,

On Thu, 1 Nov 2018 at 06:08, AKASHI Takahiro <takahiro.akashi@linaro.org> wrote:
>
> On Wed, Oct 31, 2018 at 09:54:14PM +0100, Heinrich Schuchardt wrote:
> > On 10/31/2018 01:22 PM, Alexander Graf wrote:
> > > On 10/31/2018 11:00 AM, Clément Péron wrote:
> > >> Hi,
> > >>
> > >> Trying to rebuild my SoCFPGA Cyclone V board and got this error :
> > >>
> > >> fs/built-in.o: In function `set_contents':
> > >> /home/cperon/u-boot/fs/fat/fat_write.c:831: undefined reference to
> > >> `__aeabi_ldivmod'
> > >> make: *** [Makefile:1381: u-boot] Error 1
> > >>
> > >> seems to be introduced with this operation :
> > >> assert(!(cur_pos % bytesperclust));
> > >
> > > Could we maybe just use a bitmask for bytesperclust?
> > >
> > >
> > > Alex
> >
> > According to the FAT specification the cluster size is a power of two.
> > So we can write
>
> I found:
> "Count of bytes per sector. This value may take on
>  only the following values: 512, 1024, 2048 or 4096."
>
> > assert(!(cur_pos & (bytesperclust -1)));

Seems perfect ! Could you propose a patch for this ?

Thanks,
Clement

>
> It seems reasonably good.
>
> Thanks,
> -Takahiro Akashi
>
> > Cf. patch
> > https://lists.denx.de/pipermail/u-boot/2018-October/346178.html
> > fs: fat: validate sector and cluster size.
> >
> > Best regards
> >
> > Heinrich