[PATCH] env: ti: boot: Fix Android boot on AM57x EVM

[Sam Protsenko]

Hi Eugeniu,

On Thu, Feb 20, 2020 at 4:33 PM Eugeniu Rosca <erosca at de.adit-jv.com> wrote:
>
> Hi Sam,
>
> On Wed, Feb 19, 2020 at 08:27:52PM +0200, Sam Protsenko wrote:
> > When applying DTBO on top of DTB (with "fdt apply" command) on AM57x EVM
> > board, there is not enough memory reserved in RAM for DTB blob. Hence,
> > DTBO can't be merged in DTB. It leads to inability to boot Android with
> > next error message:
> >
> >     failed on fdt_overlay_apply(): FDT_ERR_NOSPACE
> >
> > To overcome that issue let's provide 1 MiB of space to keep DTB and all
> > merged DTBO blobs. To do so, "length" parameter should be specified for
> > "fdt addr" command:
> >
> >     => fdt addr $fdtaddr 0x100000
>
> I am not an everyday user of this platform, hence curious what are the
> usual sizes of DTB and DTBO files employed in Android booting?
>

DTB/DTBO files are not big for AM57x EVM, the same order of magnitude
as yours. Actually it makes sense to reduce 1 MiB I used to 512 KiB,
because:

    fdtaddr=0x88000000

and next used address after this:

    rdaddr=0x88080000

so if I make the fdt size = 512 KiB, it gives us exactly the gap
between $fdtaddr and $rdaddr, which is 0x80000.

Thanks for the review! I will send v2 soon.

> For comparison, below are the sizes of R-Car3 DTB (Linux v5.6-rc2):
>
> $ du -sh arch/arm64/boot/dts/renesas/r8a779*dtb | sort -n
> 32K     arch/arm64/boot/dts/renesas/r8a77961-salvator-xs.dtb
> 32K     arch/arm64/boot/dts/renesas/r8a77980-v3hsk.dtb
> 44K     arch/arm64/boot/dts/renesas/r8a77990-ebisu.dtb
> 52K     arch/arm64/boot/dts/renesas/r8a77965-ulcb.dtb
> 60K     arch/arm64/boot/dts/renesas/r8a77960-ulcb.dtb
> 60K     arch/arm64/boot/dts/renesas/r8a77965-salvator-x.dtb
> 60K     arch/arm64/boot/dts/renesas/r8a77965-salvator-xs.dtb
> 60K     arch/arm64/boot/dts/renesas/r8a77965-ulcb-kf.dtb
> 64K     arch/arm64/boot/dts/renesas/r8a77960-salvator-x.dtb
> 64K     arch/arm64/boot/dts/renesas/r8a77960-salvator-xs.dtb
> 64K     arch/arm64/boot/dts/renesas/r8a77960-ulcb-kf.dtb
> 68K     arch/arm64/boot/dts/renesas/r8a77950-ulcb.dtb
> 68K     arch/arm64/boot/dts/renesas/r8a77951-ulcb.dtb
> 72K     arch/arm64/boot/dts/renesas/r8a77950-salvator-x.dtb
> 72K     arch/arm64/boot/dts/renesas/r8a77950-ulcb-kf.dtb
> 72K     arch/arm64/boot/dts/renesas/r8a77951-salvator-x.dtb
> 72K     arch/arm64/boot/dts/renesas/r8a77951-salvator-xs.dtb
> 72K     arch/arm64/boot/dts/renesas/r8a77951-ulcb-kf.dtb
>
> FWIW based on the above values, Renesas scripts reserve 512K for DTB.
>
> >
> > Also add size variables to 'adtimg' command invocations, to avoid
> > cluttering the console with DTBO blob sizes.
>
> Looks good to me.
>
> >
> > Signed-off-by: Sam Protsenko <joe.skb7 at gmail.com>
>
> Reviewed-by: Eugeniu Rosca <rosca.eugeniu at gmail.com>
>
> --
> Best Regards
> Eugeniu Rosca