nanobsd image boot issues

[Rick van der Zwet]

Boot delay and fail issues on various hardware using nanobsd generated
RELENG_7_1 images on a sandisk 2gb CF (SDCFH2-002G). For example while
trying to run a image on a soekris net4521 (bios 1.33) it seems to
take ages (up to a minute) to start booting. Same image supplied to a
PC (intel Pentium 1 & award bios) using a CF->IDE converter does not
seems to boot at all, neither does a net4801 (bios 1.33). Just seems
trying to find a boot loader. The net4801 even bails out after a
while. Output of fdisk of image list as follows:

    Disk: /dev/disk3	geometry: 992/64/63 [4001760 sectors]
    Signature: 0xAA55
             Starting       Ending
     #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
    ------------------------------------------------------------------------
    *1: A5    0   1   1 -  491  15  63 [        63 -     495873] FreeBSD
     2: A5  492   1   1 -  983  15  63 [    495999 -     495873] FreeBSD
     3: A5  984   0   1 -  992  15  63 [    991872 -       9072] FreeBSD
     4: 00    0   0   0 -    0   0   0 [         0 -          0] unused


 A reference pfSense image put on the same CF card is boot perfectly
fine under the net4521 & PC (untested net4801):

    Disk: /dev/rdisk3	geometry: 992/64/63 [4001760 sectors]
    Signature: 0xAA55
             Starting       Ending
     #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
    ------------------------------------------------------------------------
     1: 00    0   0   0 -    0   0   0 [         0 -          0] unused
     2: 00    0   0   0 -    0   0   0 [         0 -          0] unused
     3: 00    0   0   0 -    0   0   0 [         0 -          0] unused
    *4: A5    0   0   1 - 1023 254  63 [         0 -      50000] FreeBSD

Which makes me wonder about the sector start, why does nanobsd not
start at sector 0, but uses sector 63 as a start instead. Could that
be the explanation or is something else going on?

/Rick
-- 
http://rickvanderzwet.nl