Hey Kaustabh, Simon, On Wednesday, 10 June 2026 at 4:41 AM, Kaustabh Chakraborty <[email protected]> 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 > > <[email protected]> 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/[email protected]/ > >> Signed-off-by: Sam Day <[email protected]> > >> > >> 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. > >
