Hi Sam,
On 6/7/26 01:05, Sam Day wrote:
Salutations Casey,
On Saturday, 6 June 2026 at 10:03 PM, Casey Connolly
<[email protected]> wrote:
Hi Sam,
On 6/6/26 02:52, Sam Day via B4 Relay wrote:
U-Boot is seeing increasing adoption on pocket computers, many of which
(sadly) have fused bootloader chains. Many of these bootloaders have a
very rigid definition of what a "valid" downstream payload looks like.
Sometimes it's just a boring old v0/v2 Android boot image. Sometimes
it's something decidedly more grotesque.
To date, this last-mile packaging step has been trapped in downstream CI
pipelines, blogposts, documentation, etc. This patch series aims to
gather up all that esoterica and institutional knowledge and codify it
in U-Boot's build system, using binman.
Awesome!!! :D
So happy to see this being worked on, it's a huge benefit to have this
here in the build system.
That said, I think we need a bit of discussion around binman, I
previously worked on using it for teaching the build system to emit .mbn
files (see [1]), in the end getting binman to co-operate was a bunch of
really annoying work and I wound up with a sub-par result.
Yes, I saw that series. I tried to engage you on Matrix about it a few days ago
to get a sense for why you felt that binman was unsalvageable. I should have
engaged you properly here on the list, that's my bad.
The new approach which made a whole lot more sense is to use a vendor
Makefile fragment to add a custom build target, skip dealing with binman
and just have the necessary info in Python (since adding a table entry
to a Python script is really no different to adding a binman DTB node).
That's in [2].
I would prefer to use binman. It's already well documented. It's already in
use by countless other boards in U-Boot. I prefer maintaining DTSI's for the
configuration DSL than some Python dicts. Also, at some point once enough
devices have their native Android boot artifact described, there will be
clear patterns that can be neatly tucked away into shared DTSI fragments.
From my side, binman is a no-go for a bunch of reasons, polluting the
device dtb being a big one, the ability to debug and maintain it is also
not something i feel particularly confident about. Hence having a
standalone tool would be the appropriate way to go for this, I really
want to avoid having to learn this bespoke overly complex build tooling
when it's selling points aren't things that have much value for Qualcomm.
I'm really not in favour of adding a binman node to the DTB that U-Boot
uses, and I think it's kinda dumb that this is the only sensible way to
configure binman today...
I see nothing wrong with that. Can you expand on your concerns a little more?
It really just goes against the goal of using upstream DT. Previously I
managed to get binman to parse its config from a separate DTB but that
was hellish to integrate the tooling for.
Having this random node at runtime for completely unnecessary arbitrary
reasons feels just wrong to me.
The way that mkmbn works is it just has all the device-specific config
in a dictionary where the key is the compatible string, it finds the DTB
in the U-Boot image and gets the appropriate mbn config from there.
I see you've clearly put a lot of effort into this, and I hate to ask
you to do a lot more, but I'd really like to avoid using binman, would
you be willing to rework this to put the config in Python and just have
a custom make target like in the mkmbn patches? You can probably base it
on top.
I'm definitely not interested in doing that. I would, however, be very willing
to address any specific concerns you have with binman.
That's a shame to hear>
At any rate, if you want to NAK any binman usage in the qualcomm side, that's
fair enough. Please let me know if you see absolutely no path forward, and I'll
split the series to just focus on the binman etype impls and their usage on
the Exynos side. That would be a bummer, but I'm intending to maintain a
long-lived close-to-mainline downstream anyway, so I would continue widening
the support there and hope that your opinion on binman changes in future :D
I don't feel comfortable depending on binman for Qualcomm, so we'll
leave it there.
Kind regards,
// Casey>
This way it avoids the need to add stuff to the dtb, you can just parse
`u-boot.dtb` to determine the device and pick the right config.
[1]:
https://lore.kernel.org/u-boot/20250722-b4-qcom-tooling-improvements-v5-0-df143f124...@linaro.org/
[2]:
https://lore.kernel.org/u-boot/20260511-b4-qcom-tooling-improvements-v7-0-0c06346e7...@linaro.org/
I wonder if maybe the ELF wrangling in particular was cursed? I had absolutely
no issues using binman and getting it to produce native binaries for a
half-dozen disparate devices.
Cheers,
-Sam
Put differently: an overwhelming majority of these pocket computer
devices have a "canonical" payload format that U-Boot currently has no
support for. Let's fix that.
The first patches in this series introduce an `android_boot` etype. To
begin with, this is a "typical" abootimg, as defined by canonical AOSP
sources and reference `fastboot`/`mkbootimg` implementation. There's
plenty of devices out there with a sane(-ish, nothing in Android-land is
ever truly sane) bootloader that will happily chain a U-Boot rolled into
the kernel section of an abootimg.
With that out of the way, the cursed bootloaders are next to be
supported. Binman etypes for Qualcomm's "QCDT" and Samsung's "DTBH"
formats are implemented. These are non-standard vendor-specific
devicetree containers, which the previous bootloader uses to pick a FDT
to boot the downstream with.
In both cases, these vendor-specific formats are tacked on to the end of
a v0 abootimg, with the header_version being hijacked to encode the
length of this following payload. Thus, the android_boot etype is
retrofitted to allow these shenanigans.
Binman configs that produce flashable boot artifacts are introduced for
the following devices:
* google-sargo (vanilla v2)
* oneplus-fajita (vanilla v2)
* samsung-a5u-eur (QCDT v0)
* samsung-gt510 (QCDT v0)
* samsung-j7xelte (DTBH v0)
I also successfully tested a vanilla v0 on my samsung-expressltexx, in
conjunction with the qcom-armv7 series already on the list. However,
since that work is still in-flight and the expressltexx DTS is
downstream, I opted not to include it here.
Signed-off-by: Sam Day <[email protected]>
---
Sam Day (13):
binman: Android boot image support
.gitignore: ignore binman-generated blobs
arch: arm: qcom: google-sargo binman config
qcom: arch: arm: qcom: sdm845-fajita binman configs
mach-snapdragon: enable BINMAN
binman: android_boot: vendor-dt support
binman: Add QCDT support
binman: android_boot: SEANDROIDENFORCE support
arch: arm: qcom: samsung-a5u-eur binman config
arch: arm: qcom: samsung-gt510 binman config
binman: Add DTBH support
arch: arm: exynos: add j7xelte binman config
configs: exynos-mobile: pull in BINMAN
.gitignore | 1 +
arch/arm/Kconfig | 1 +
arch/arm/dts/exynos-mobile.dtsi | 5 +
arch/arm/dts/exynos7870-j7xelte-u-boot.dtsi | 24 ++
arch/arm/dts/msm8916-samsung-a5u-eur-u-boot.dtsi | 39 ++
arch/arm/dts/msm8916-samsung-gt510-u-boot.dtsi | 39 ++
arch/arm/dts/qcom.dtsi | 5 +
arch/arm/dts/sdm670-google-sargo-u-boot.dtsi | 27 ++
arch/arm/dts/sdm845-oneplus-fajita-u-boot.dtsi | 25 ++
arch/arm/mach-exynos/Kconfig | 1 +
configs/exynos-mobile_defconfig | 1 +
configs/qcom_defconfig | 1 +
tools/binman/etype/android_boot.py | 408
+++++++++++++++++++++
tools/binman/etype/dtbh.py | 173 +++++++++
tools/binman/etype/qcdt.py | 160 ++++++++
tools/binman/ftest.py | 127 +++++++
.../test/vendor/android_boot_seandroidenforce.dts | 22 ++
tools/binman/test/vendor/android_boot_v0.dts | 29 ++
tools/binman/test/vendor/android_boot_v2.dts | 46 +++
.../binman/test/vendor/android_boot_vendor_dt.dts | 27 ++
tools/binman/test/vendor/dtbh.dts | 29 ++
tools/binman/test/vendor/dtbh_bad_model_info.dts | 19 +
tools/binman/test/vendor/qcdt.dts | 20 +
tools/binman/test/vendor/qcdt_bad_msm_id.dts | 17 +
24 files changed, 1246 insertions(+)
---
base-commit: a4c8728f225b0d7d591fb9199ce7efb72f48290e
change-id: 20260604-android-binman-ad7a43f4e99d
Best regards,
