Re: Supermicro R12SPD Ampere Altra - No valid device tree blob found

Reply: Warner Losh : "Re: Supermicro R12SPD Ampere Altra - No valid device tree blob found"
In reply to: John : "Supermicro R12SPD Ampere Altra - No valid device tree blob found"
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From: Mark Millard <marklmi_at_yahoo.com>
Date: Mon, 17 Jul 2023 17:14:57 UTC

On Jul 17, 2023, at 09:37, John <jwd@FreeBSD.org> wrote:

> Hi Folks,
> 
>   I have a new Supermicro system:
> 
> Supermicro R12SPD BIOS Date:04/26/2023 Rev:1.1a
> CPU : Ampere(R) Altra(R) Max Processor
> 
>   Booting from the latest media (spot checking older
> media makes no difference):
> 
> Boot Media: FreeBSD-14.0-CURRENT-arm64-aarch64-20230713-510fd8313800-264135-disc1.iso
> 
>   Fails here:
> 
> Loading kernel...
> /boot/kernel/kernel text=0x2a8 text=0x8ff810 text=0x29b324 data=0x153cc8 data=0x0+0x2c3000 0x8+0x155628+0x8+0x17e504|
> Loading configured modules...
> can't find '/etc/hostid'
> can't find '/boot/entropy'
> No valid device tree blob found!
> WARNING! Trying to fire up the kernel, but no device tree blob found!
> EFI framebuffer information:
> addr, size     0x10000000, 0x300000
> dimensions     1024 x 768
> stride         1024
> masks          0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000
> 
> 
>   If I break into the loader, the fdt command shows the
> same error message.
> 
> OK fdt ls
> No device tree blob found!
> 
> OK 
> 
>   A verbose boot shows no additional information.
> 
>   I've poked around in the source and don't see an obvious
> fix for this. Web searches have also not provided any
> obvious solutions.
> 
>  Any ideas? Thoughts?

UEFI/ACPI booting does not have a "device tree blob" to find but
FreeBSD's UEFI laoder still puts out the "No valid device tree
blob found!". I see this on all the UEFI/ACPI booting systems that
I have access to --and they all boot fine, aarch64 system and the
amd64 system.

I expect that your boot context is UEFI/ACPI and that the message
has mislead you about what to look for relative to booting.

But I could be wrong and the system could be trying to boot via
fdt. That is one of the problems with the way this messaging is
handled.

On the HoneyComb (16 Cortex-A72's), for example, there
is the FreeBSD loader's configuration command:

OK configuration
NumberOfTableEntries=12
  76b6bdfa-2acd-4462-9e3f-cb58c969d937 at 0xfad05b18
  fc1bcdb0-7d31-49aa-936a-a4600d9dd083 at 0xfaabfd98
  DXE Table at 0xfacea6b0
  HOB List Table at 0xfaabd018
  MemoryTypeInformation at 0xfacea338
  Debug Image Info Table at 0xfad038d8
  a4ee0728-e5d7-4ac5-b21e-658ed857e834 at 0xfaccea98
  ACPI 2.0 Table at 0xef890018
  SMBIOS3 Table at 0xfacb0000
  dcfa911d-26eb-469f-a220-38b7dc461220 at 0xee5cb018
  HII database at 0xee550018
  HII config routing at 0xee530018

For this context, it indicates a UEFI/ACPI boot: note the
"ACPI 2.0 Table at". FDT booting would refer to such instead.

So you likely can check if you are UEFI/ACPI booting vs.
FDT booting.

It is technically possible to have an environment that could
list both. I've no experience with booting such a system or
other knowledge of how FreeBSD handles such.

===
Mark Millard
marklmi at yahoo.com