[PATCH 1/3] spl: fit: Minimally parse OS properties with FIT_IMAGE_TINY

Jagan Teki jagan at amarulasolutions.com
Mon Jun 1 19:04:36 CEST 2020


On Fri, May 8, 2020 at 4:49 AM Samuel Holland <samuel at sholland.org> wrote:
>
> Some boards, specifically 64-bit Allwinner boards (sun50i), are
> extremely limited on SPL size. One strategy that was used to make space
> was to remove the FIT "os" property parsing code, because it uses a
> rather large lookup table.
>
> However, this forces the legacy FIT parsing code path, which requires
> the "firmware" entry in the FIT to reference the U-Boot binary, even if
> U-Boot is not the next binary in the boot sequence (for example, on
> sun50i boards, ATF is run first).
>
> This prevents the same FIT image from being used with a SPL with
> CONFIG_SPL_FIT_IMAGE_TINY=n and CONFIG_SPL_ATF=y, because the boot
> method selection code looks at `spl_image.os`, which is only set from
> the "firmware" entry's "os" property.
>
> To be able to use CONFIG_SPL_ATF=y, the "firmware" entry in the FIT
> must be ATF, and U-Boot must be a loadable. For this to work, we need to
> parse the "os" property just enough to tell U-Boot from other images, so
> we can find it in the loadables list to append the FDT, and so we don't
> try to append the FDT to ATF (which could clobber adjacent firmware).
>
> So add the minimal code necessary to distinguish U-Boot/non-U-Boot
> loadables with CONFIG_SPL_FIT_IMAGE_TINY=y. This adds about 300 bytes,
> much less than the 7400 bytes added by CONFIG_SPL_FIT_IMAGE_TINY=n.
>
> Signed-off-by: Samuel Holland <samuel at sholland.org>
> ---

+ Andre


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