On Tue, Sep 08, 2026 at 12:31:10AM +0800, Eric Chung wrote: > On Mon, Sep 7, 2026 at 4:51 PM Yao Zi <[email protected]> wrote: > > > > On Sun, Sep 06, 2026 at 05:11:08PM +0800, Eric Chung wrote: > > > Add document on how to flash images into eMMC of K1 SoC based boards. > > > > > > Signed-off-by: Eric Chung <[email protected]> > > > > > > --- > > > v9: > > > - Add to generate the partition table of SD card. > > > v3: > > > - Add document on how to flash images into SD card. > > > --- > > > board/spacemit/k1/MAINTAINERS | 2 +- > > > doc/board/spacemit/index.rst | 1 + > > > doc/board/spacemit/k1-mmc.rst | 271 > > > ++++++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 273 insertions(+), 1 deletion(-) > > > > ... > > > > > diff --git a/doc/board/spacemit/k1-mmc.rst b/doc/board/spacemit/k1-mmc.rst > > > new file mode 100644 > > > index 000000000000..0be5d5fa1c39 > > > --- /dev/null > > > +++ b/doc/board/spacemit/k1-mmc.rst > > > > ... > > > > > +Chapter 2: SD Card Boot > > > +======================= > > > + > > > + > > > +SpacemiT K1 Bianbu SD Card Image Flashing and U-Boot Update Guide > > > +================================================================== > > > + > > > +This guide explains how to prepare a bootable SD card with Bianbu OS for > > > +SpacemiT K1 based boards and how to replace the U-Boot binary on the SD > > > +card with a custom build. > > > + > > > +Prerequisites > > > +~~~~~~~~~~~~~ > > > + > > > +- A SpacemiT K1 based development board > > > +- A microSD card (at least 4GB capacity recommended) > > > +- A card reader for your host computer > > > +- A Linux host system (for ``dd``, ``sgdisk``, ``lsblk`` commands) > > > +- The Bianbu release package from > > > + > > > <https://archive.spacemit.com/image/k1/version/bianbu/v2.3.3/Bianbu-Minimal-K1-V2.3.3-20260128183217.zip> > > > +- A custom ``FSBL.bin`` and ``u-boot.itb`` file to be written to the > > > U-Boot > > > + partition > > > + > > > +Prepare the SD Card & the image > > > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > + > > > +**1. Obtain the release images** > > > + > > > +Unpack the release package to get the image files. Replace the > > > ``FSBL.bin`` > > > +and ``u-boot.itb`` with your custom builds. > > > + > > > +**2. Identify the SD card device** > > > + > > > +Insert the microSD card into your card reader, then run: > > > + > > > +.. code-block:: console > > > + > > > + $ lsblk > > > + > > > +Compare the output before and after inserting the card to identify > > > +the new device. It will typically appear as ``/dev/sdb``, ``/dev/sdc``, > > > +or ``/dev/mmcblk0``. > > > + > > > +**3. Write the image to the SD card** > > > + > > > +Run ``sgdisk`` to generate the partition table, then use ``dd`` to write > > > +the images to the corresponding partitions. > > > + > > > +.. code-block:: console > > > + > > > + $sudo sgdisk -o /dev/sdb > > > + $sudo sgdisk -a 128 \ > > > + -n 1:256:767 -t 1:8300 \ > > > + -n 2:768:895 -t 2:8300 \ > > > + -n 3:2048:4095 -t 3:8300 \ > > > + -n 4:4096:8191 -t 4:8300 \ > > > + -n 5:8192:532479 -t 5:8300 \ > > > + -n 6:532480:4726783 -t 6:8300 \ > > > + /dev/sdb > > > + $sudo dd if=FSBL.bin of=/dev/sdb1 bs=512 seek=0 status=progress > > > + $sudo dd if=env.bin of=/dev/sdb2 bs=512 seek=0 status=progress > > > + $sudo dd if=fw_dynamic.itb of=/dev/sdb3 bs=512 seek=0 status=progress > > > + $sudo dd if=u-boot.itb of=/dev/sdb4 bs=512 seek=0 status=progress > > > + $sudo dd if=bootfs.img of=/dev/sdb5 bs=1M status=progress > > > + $sudo dd if=rootfs.ext4 of=/dev/sdb6 bs=1M status=progress > > > > The bootfs/rootfs part aren't U-Boot-related stuff, so please omit them > > from this documentation to keep it simplified. > > > > Then the only binary we need to extract from the "SpacemiT release > > package" is env.bin and fw_dynamic.bin. > > > > For env.bin, I think this U-Boot port depends on no specific environment > > setttings? If no, please omit it, too; otherwise please provide a .env > > file in upstream U-Boot tree, and make it the default environment to > > use. > > OK. I can drop these binaries. > > > > > For fw_dynamic.bin, I think SpacemiT K1 support has been landed in the > > upstream OpenSBI tree? Please check if it works with upstream U-Boot. > > If no, please try fixing it, and then it's okay to stick to the > > downstream OpenSBI, but you need providing a guidance to build it from > > source if possible. > > The patch set is for MMC/SD. OpenSBI is another topic that does not > belong to u-boot either. They should not be mixed together.
At least "which OpenSBI variants are compatible with this port" should belong to this documentation, because your port requires a functional OpenSBI image to boot. If you really do not want to include the build steps here, though it could be very brief to only one or two paragraphs, please check upstream OpenSBI, and if it works, describe the minimum required OpenSBI version, and the platform to build; if not, please mention which downstream OpenSBI should be used instead, how to build it, and if you could figure it out, why. > I prefer to address one topic per patch set. > > > > Then you could fully omit the step of downloading the "SpacemiT release > > package". Regards, Yao Zi
