Creating an i386 root disk that can boot

[Joel <joelp%sdf.org@localhost>]

Hello -- It's that time of year to play with NetBSD 10.1 and some old 
hardware!

I'm having trouble creating a bootable disk for my old i386 laptop (1998 
Satellite Pro 445). It starts to boot, then fails with an error:
    NetBSD/x86 ffsv2 Primary Bootstrap
    Boot failed (errno  2): Can't open /boot
    Insert system disk in drive.
    Press any key when ready....

Can someone advise what I'm failing to do to create an i386 bootable drive?

I followed instructions in installboot(8). Specifically, with the CF 
disk with adapter attached as /dev/sd0:

    fdisk -c ./mbr /dev/rsd0c
    installboot -v -m i386 /dev/rsd0a ./bootxx_ffsv2

Here's the output from installboot:
    File system:         /dev/rsd0a
    Primary bootstrap:   ./bootxx_ffsv2
    Boot options:        timeout 5, flags 0, speed 9600, ioaddr 0, 
console pc

Both mbr and bootxx_ffsv2 are from my own NetBSD-10.1 i386 build. I have 
kern-GENERIC and base, modules, and etc sets installed on 'a'.

This is the only i386 device I have so I run fdisk and installboot from 
my AMD64 build machine.

I know the CF to IDE adapter works as I can successfully boot an i386 
install image downloaded from netbsd.org.

Unfortunately this old laptop cannot boot from USB or PXE, and the FD 
and CDROM drives long since died; hence the need to create a bootable image.

Here is what fdisk and disklabel look like for the CF:

Disk: /dev/sd0
NetBSD disklabel disk geometry:
cylinders: 3815, heads: 64, sectors/track: 32 (2048 sectors/cylinder)
total sectors: 7813120, bytes/sector: 512
 
                  BIOS disk geometry:
cylinders: 487, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 7813120

Partitions aligned to 2048 sector boundaries, offset 2048

Partition table:
0: NetBSD (sysid 169)
    start 2048, size 6141952 (2999 MB, Cyls 0-382/113/51), Active
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
First active partition: 0
Drive serial number: 0 (0x00000000)

# /dev/sd0:
type: ESDI
disk: image
label:
flags:
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 64
sectors/cylinder: 2048
cylinders: 3000
total sectors: 6144000
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0

8 partitions:
#        size    offset     fstype [fsize bsize cpg/sgs]
 a:   5939200      2048     4.2BSD   1024  8192    16  # (Cyl.      1 - 
  2900)
 b:    202752   5941248       swap                     # (Cyl.   2901 - 
  2999)
 c:   6144000         0     unused      0     0        # (Cyl.      0 - 
  2999)
 d:   6141952      2048     unused      0     0        # (Cyl.      1 - 
  2999)


Thanks - Joel