Re: Installing NetBSD on Jetson Nano

[Jason Mitchell <jmitchel%bigjar.com@localhost>]

On 1/19/22 4:43 AM, Dan MacDonald wrote:
> I've not been able to find any instructions or confirmation that it is
> possible to install NetBSD on the Jetson Nano other than a NetBSD
> mailing list post from Jared McNeil saying that I would need to use
> the tegra210-p3450-0000.dtb:
>
> http://mail-index.netbsd.org/port-arm/2020/01/31/msg006479.html
>
> I’ve tried the NetBSD 9.2 evbarm-aarch64 image and it wouldn’t boot
> for me, likely because it doesn't include the tegra210-p3450-0000.dtb.
>
> Would I need to build NetBSD 10 from source to install it on my Jetson
> Nano or are there pre-built NetBSD arm64 images somewhere that do
> include the required dtb and u-boot? I don't think the Jetson Nano
> supports UEFI.
>
> Recent versions of Jetpack (the reference OS for Jetson devices) and
> Armbian let me boot straight from USB 3. Might this also be possible
> with NetBSD or will I only be able to boot from MicroSD?
>
> Thanks

Hello,

    From what I understand the boot process for ARM devices goes like this:

1) Device power on

1b) There could be a step here if there's some nvidia specific code on 
the SPI flash or in ROM

2) Load u-boot from SPI flash or boot device*

3) Load EFI code on the DOS partition and execute it

4) The EFI code looks for a kernel on an FFS partition and executes it.

    The questions I don't know the answer to are:

1) Does the Jetson Nano have u-boot installed in SPI flash?

2) If u-boot is present on the boot media and in SPI flash which is 
loaded first?

3) Where does the Jetson expect u-boot to be on the boot drive

    It looks like you're using a generic image which probably doesn't 
have u-boot on it. There's a package in pkgsrc (and also in pkgsrc-wip) 
containing u-boot for the Jetson nano (sysuttils/u-boot-jetson-nano). If 
you downloaded that you could copy it onto a microSD card that contained 
the base NetBSD ARM image (arm64.img.gz). I thought the package would 
print the dd command necessary to install the u-boot file, but it 
doesn't look like it does. I think:

    dd if=u-boot of=/dev/*disk* seek=64     is the command for other 
platforms.

    To boot NetBSD off of a USB device I'm nearly certain you'll need 
to load u-boot into the SPI flash. Maybe the Jetson will look for u-boot 
on a USB device , I don't know.

    My understanding of this is incomplete, but hopefully this will 
shed some light on the subject.

HTH,

Jason M.

* u-boot lives in unallocated space between the MBR and the DOS 
partition starting at 0x8000 on the disk (at least on some ARM chips)