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Re: PBR not bootable (eek!)

"Eric d'Halibut" <> writes:

> I put NetBSD 6.0 on ancient Micron full tower -- dual PPro 180mhz

Cool; that almost qualifies as retrocomputing - most old i386 stuff is
just junk, but that's interesting.

> Some time spent on google suggested 'installboot' might be the remedy,
> but I am in over my head with that util I am afraid (as well as with
> MUCH else besides, clearly <g>).

So, if you can make a disklabel, newfs, use the fs, then the disk is
basically ok.

Some hints:

man boot(8)

The boot process on i386 has three stages:

  1) fdisk -c /usr/mdec/mbr_bootsel
  2) installboot, bootxx_ffsvX (depending; I use a smallish root with
  UFS1, and bigger data with UFS2)
  3) /boot (copied from /usr/mdec to /)

first the bios loads the mbr
the mbr loads the first sector of the active partition
that loads bootxx from after the label
the bootxx_ loads /boot from the filesystem
/boot loads /netbsd etc.

In a partition, it's mbr, disklabel, bootxx_.

The part I'm fuzzy on is whether you need an mbr boot block in the first
block of a partition that starts at 63, but I think so.

I hope this helps.  Don't be afraid to read installboot really slowly
and try to follow it, and to use -v when running it.

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