I’m using core OS on an aarch64 SBC(rk3399-nanopi-r4s). The boot process seems to be uboot → grub.efi → efistub → linux. But from what I can tell, uboot ends up using it’s own internal devicetree when linux calls into efi_install_fdt:
While that seems to work, wouldn’t it be better if it GRUB would load the FDT from /boot/ostree/fedora-coreos-*/dtb/? That way it’d be ensured that the contents of the FDT are actually compatible with the selected kernel version.
I have to admit that the SBC/Arm world has a lot of corners that I’m not fully versed in so there’s a lot of things I don’t understand.
Nice! I’d actually really like to see the steps you used to do this (maybe a blog?). We do have the Raspberry Pi 4 docs. Did you use a similar workflow?
I actually have no idea 
- Maybe @pwhalen would know.
ansible + podman-systemd-units are an awesome combination 
, they allow me to publish my whole setup:
Basically you just have to build and flash uboot into the reserved partition. On rk3399 it’s more complicated because the reserved partition is too small for that. So I simply modified the image to increase the size. Updates are still possible since they don’t touch the partition table or firmware.
I also have a homeserver setup with the same SoC(but a different board: ROCK 4 Model A+). There I cheated by flashing uboot to the internal MMC so I don’t need the reserved partition on the eMMC 
This is all really awesome! Thank you for sharing.
Thanks @m1cha for documenting a workaround. I’ve tried it for the NanoPi Neo2 board but unfortunately this did not work and I’m not knowledgeable enough in uboot to understand why 
.
The installation of Fedora IoT via the arm-image-installer worked however so there is likely something that I am missing.
Some logs:
$ cat layout.sfdisk ~/projects/boards|10:47
label: gpt
label-id: 00000000-0000-4000-A000-000000000001
device: fedora-coreos-38.20230819.3.0-metal.aarch64.raw
unit: sectors
first-lba: 34
last-lba: 5625822
sector-size: 512
fedora-coreos-38.20230819.3.0-metal.aarch64.raw1 : start= 2048, size= 30720, type=8DA63339-0007-60C0-C436-083AC8230908, uuid=67FE0990-A162-4641-BDA7-CD8F66226996, name="reserved"
fedora-coreos-38.20230819.3.0-metal.aarch64.raw2 : start= 32768, size= 260096, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=55688478-B2F7-40A3-A730-66ECA6F751C1, name="EFI-SYSTEM"
fedora-coreos-38.20230819.3.0-metal.aarch64.raw3 : start= 292864, size= 786432, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=69F3707F-449F-455C-BBBF-D999467DD5D7, name="boot"
fedora-coreos-38.20230819.3.0-metal.aarch64.raw4 : start= 1079296, size= 4507615, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=35DD1EEE-5A08-4254-B4CA-F5A6F6CB283D, name="root"
From https://pagure.io/arm-image-installer/blob/main/f/socs.d/AllWinner:
$ dnf download uboot-images-armv8.noarch
$ <extract "/usr/share/uboot/nanopi_neo2/u-boot-sunxi-with-spl.bin" from RPM archive above>
$ sudo dd if=u-boot-sunxi-with-spl.bin of=/dev/sdXYZ bs=1024 seek=8; sync; sleep 5
$ <Update kernel command line "options" in BLS config with "console=..." argument>
uboot serial log:
U-Boot SPL 2023.04 (Jun 11 2023 - 00:00:00 +0000)
DRAM: 512 MiB
Trying to boot from MMC1
NOTICE: BL31: v2.8(release):
NOTICE: BL31: Built : 00:00:00, Jan 18 2023
NOTICE: BL31: Detected Allwinner H5 SoC (1718)
NOTICE: BL31: Found U-Boot DTB at 0x20a2c78, model: FriendlyARM NanoPi NEO 2
NOTICE: PMIC: Assuming H5 reference regulator design
U-Boot 2023.04 (Jun 11 2023 - 00:00:00 +0000) Allwinner Technology
CPU: Allwinner H5 (SUN50I)
Model: FriendlyARM NanoPi NEO 2
DRAM: 512 MiB
Core: 62 devices, 19 uclasses, devicetree: separate
WDT: Not starting watchdog@1c20ca0
MMC: mmc@1c0f000: 0
Loading Environment from FAT... ** No valid partitions found **
In: serial
Out: serial
Err: serial
Net: eth0: ethernet@1c30000
starting USB...
Bus usb@1c1a000: USB EHCI 1.00
Bus usb@1c1a400: USB OHCI 1.0
Bus usb@1c1d000: USB EHCI 1.00
Bus usb@1c1d400: USB OHCI 1.0
scanning bus usb@1c1a000 for devices... 1 USB Device(s) found
scanning bus usb@1c1a400 for devices... 1 USB Device(s) found
scanning bus usb@1c1d000 for devices... 1 USB Device(s) found
scanning bus usb@1c1d400 for devices... 1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc0 is current device
** Invalid partition 1 **
Couldn't find partition mmc 0:1
Device 0: unknown device
ethernet@1c30000 Waiting for PHY auto negotiation to complete....... done
BOOTP broadcast 1
DHCP client bound to address 192.168.1.137 (2047 ms)
*** ERROR: `serverip' not set
Cannot autoload with TFTPGET
missing environment variable: pxeuuid
Retrieving file: pxelinux.cfg/01-02-01-e5-49-3b-4f
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A80189
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A8018
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A801
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A80
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A8
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0A
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C0
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/C
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/default-arm-sunxi-sunxi
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/default-arm-sunxi
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/default-arm
*** ERROR: `serverip' not set
Retrieving file: pxelinux.cfg/default
*** ERROR: `serverip' not set
Config file not found
BOOTP broadcast 1
DHCP client bound to address 192.168.1.137 (2003 ms)
*** ERROR: `serverip' not set
Cannot autoload with TFTPGET
BOOTP broadcast 1
DHCP client bound to address 192.168.1.137 (2003 ms)
*** ERROR: `serverip' not set
Cannot autoload with TFTPGET