Re: NetBSD MBR boot / Error no operating system

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Fri, 20 Apr 2018 18:31:43 +0100
    From:        Steve Binkhorn <steve%prd.co.uk@localhost>
    Message-ID:  <7a9553f1-ae0a-43f1-b48e-3491d9e7f87a%prd.co.uk@localhost>

  | fdisk reported the correct size (1TB) but said not bootable,

That's not good.   But what matters (for what I was thinking) is

BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 1953525168

that kind of info.   A 1TB disk is not likely to have sector size issues,
so that issue can probably be forgotten.

Ths issue is that when the MBR says that the partition starts at
sector N,  and the MBR boot code takes that and attempts a
bios read of cylinder 0, head 3, sector 17 (or whatever the
calculations produce) does the BIOS actually read sector N,
or somewhere different?

  | recognised it  as NetBSD.

That's just what the type field in the MBR partition table says.
Of itself, not very important (for as far as you're getting.)

  | I wonder if this is an MBR/GPT issue - out of my depth here.

GPT most probably not - if your system is reading the MBR boot
code and executing it, which it clearly is, then it is obviously
attempting a BIOS type boot.

However, BIOS emulation in modern UEFI firmware can be a bit
touch and go.

  | The target system didn't get beyond the hardware probe from an install DVD

Is this the system (I get the various threads mixed up) that halted
with a "no console found" type problem?

If so, that also suggests BIOS emulation issues (not configuring the
graphics the way NetBSD assumes a BIOS will have set it all up.)