[PATCH v2 7/8] arch: arm: exynos: add j7xelte binman config

[Sam Day]

Hey Kaustabh, Simon,

On Wednesday, 10 June 2026 at 4:41 AM, Kaustabh Chakraborty <kauschluss at disroot.org> wrote:

> Allow me to chime in and provide some context for discussions below:
> 
> On 2026-06-08 07:27 -06:00, Simon Glass wrote:
> > Hi Sam,
> >
> > On 2026-06-07T23:37:09, Sam Day via B4 Relay
> > <devnull+me.samcday.com at kernel.org> wrote:
> >> arch: arm: exynos: add j7xelte binman config
> >>
> >> Note that, as of this commit, j7xelte does not yet exist in U-Boot's
> >> upstream DTS tree. It was accepted into next so it should appear here
> >> eventually.
> >>
> >> S-BOOT expects a DTBH with hw-rev == 6.
> >>
> >> Link: https://lore.kernel.org/all/177209522223.26390.6219893536178441080.b4-ty@kernel.org/
> >> Signed-off-by: Sam Day <me at samcday.com>
> >>
> >> arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi | 24 ++++++++++++++++++++++++
> >>  1 file chang
> >> diff --git a/arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi b/arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi
> >> @@ -0,0 +1,24 @@
> >> +     binman {
> >> +             filename = 'u-boot-samsung-j7xelte.img';
> >> +             android-boot {
> >> +                     kernel {
> >> +                             u-boot-nodtb {};
> >> +                     };
> >
> > No 'base' is set, so android_boot falls back to its default of
> > 0x10000000, putting the kernel_addr field in the abootimg header at
> > 0x10008000 - nowhere near Exynos7870 DRAM at 0x40000000. Does S-BOOT
> > on j7xelte ignore the load addresses in the header (so the defaults
> > are harmless), or do you need to set base = <0x40000000> explicitly? A
> > short note in the commit message on what S-BOOT does with those fields
> > would help.
> 
> In my devices (on7xelte, a2corelte, j6lte), S-BOOT does ignore the load
> address. This is also mentioned in the install guide [1], as it says:
> 
>   "Offsets are not provided to mkbootimg as S-BOOT ignores them."
> 

Right. I forgot to add a comment to the j7xelte carrying along this important
quirk. That will be addressed in v3.

> >> diff --git a/arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi b/arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi
> >> @@ -0,0 +1,24 @@
> >> +                     vendor-dt {
> >> +                             dtbh {
> >> +                                     dtb-0 {
> >> +                                             u-boot-dtb { };
> >> +                                     };
> >> +                             };
> >> +                     };
> >
> > Does this indenting use tabs? It should.
> >
> > 'S-BOOT expects a DTBH with hw-rev == 6' is terse - worth a sentence
> > explaining that this pins both hw_rev and hw_rev_end to 6, contrasting
> > with the wider 0..255 range used by the j6lte overlay, so it's clear
> > why that DTSI's approach wasn't reused.
> 
> I also question this approach. In my devices S-BOOT happily accepts dtbs
> having revisions lower than that of the hardware, but of course, doesn't
> accept higher ones. Setting hw-rev to 6 means that U-Boot won't work for
> S-BOOT versions 5 or below.
> 
> If this is indeed a quirk of S-BOOT in this device, then do we need to
> make revision variants for j7xelte, or pass the revision to binman
> somehow?

So, all I was trying to accomplish here is increased specificity. That is,
since we're formalizing this process of producing canonical artifacts for
un(der-)documented platforms, I felt that nailing down the most precise
magic values for a device is preferable to cargo culting around generalized
spooky numbers :D

Since it's contentious, I'll make sure that v3 keeps the defaults casting
the net as maximally wide as possible and avoid trying to pin down the j7xelte.

Thanks all,
-Sam

> 
> > Regards,
> > Simon
> 
> [1] https://docs.u-boot-project.org/en/v2026.04/board/samsung/exynos-mobile/exynos7870.html#preparation.
> 
>