Re: fitImage align 8-byte for ARM64【请注意，邮件由u-boot-bounces at lists.denx.de代发】

[Simon Glass]

Hi Kever,


On Tue, 7 Jan 2020 at 13:27, Tom Rini <trini at konsulko.com> wrote:
>
> On Tue, Jan 07, 2020 at 09:25:53AM +0800, Kever Yang wrote:
> > Hi Tom, Simon,
> >
> >
> > On 2020/1/6 下午10:20, Tom Rini wrote:
> > > On Mon, Jan 06, 2020 at 01:47:25PM +0100, Matthias Schoepfer wrote:
> > >
> > > > Hi!
> > > >
> > > > I have had trouble booting a fitImage packed kernel for dragonboard410c,
> > > > which is an ARM64 platform. After days and days of debugging, I found that
> > > > the fdt is 4-byte aligned. But within the linux kernel,
> > > > Documentation/arm64/booting.txt says, fdt must be 8 byte aligned.
> > > >
> > > > If I change the alignment by means of fdt_high, the Kernel boots, otherwise,
> > > > it hangs.
> > > >
> > > > Is there an option to align the fitImage to 8-byte boundaries, and if not,
> > > > is it feasible to submit a patch or will this never have a chance to get
> > > > merged?!
> > > That's interesting.  It sounds like you need to look at
> > > boot_relocate_fdt() perhaps?  Thanks!
> > >
> > When I use the FIT image, I met another issue:
> >
> > - The emmc/sd read is by block which is 512byte;
> >
> > - The FIT image header is always not 512byte align, and the entry of
> >
> >   image in FIT is always not aligned to block;
> >
> > - The image read from block device always need memory coppy which
> >
> >   make it slow.
> >
> > I can truncate the image in FIT align to 512 byte, but not able to make the
> >
> > header which is dtb 512byte align,  any idea to implement this?
>
> I don't quite follow, sorry.  Don't you control where the image will be
> written to in eMMC?

In the SPL FIT implementation, it reads the blocks from MMC in such a
way that the first byte of the image is at the required load address,
and the FIT metadata is before that. See spl_load_simple_fit().

Regards,
Simon