Booting from CF

[Guest]

I am trying the boot from CF but am always getting a message indicating itis
not a bootable drive. I think it is occuring because the CF is a removable
disk (that's how it appears when I boot from XP pro anyway.) How do I force
the CF to look like it is a fixed disk? Is it possible?
thanks
kevin

 

[JC]

That's a trick question. First you have to make sure that the CF slot in
your hardware, and the hardware's BIOS support CF boot, and then there is a
utility that you can obtain from the flash MFR (SanDisk, Lexar, PNY, ETC)
that you can run on the flash to mark it as non-removable. Should be on
their respective websites under downloads/utilities.

HTH,
JC

 

[Johannes Stratmann]

it is possible for XPe to boot from a removable CF, but the problem will be
the different disk geometry: when you format the CF in a card reader adapter
it will be treated different than from your BIOS in the target machine. So
you need to create the NTFS partition on the target machine. THEN you may
have the removable problem if you use W2k or XP: some tools as partition
magic do not work with removable disks. I needed to format with with
partition magic because the XP diskmanager gives less free space as other
formatting tools ! I have not played with diskpart, this may be also a
solution.
A great step would be a formatting tool where you can specify the disk
geometry so that it will match the BIOS on the target machine. The
interesting thing is that Windows disk.sys can read the disk that was
formatted with another geometry on the target machine, so this should be
possible.

 

[Slobodan Brcin \(eMVP\)]

Hi Johannes,

The interesting thing is that Windows disk.sys can read the disk that was
formatted with another geometry on the target machine, so this should be
possible.

Actually this is not an interesting thing since windows do not use disk geometry (CHS) information but instead it always uses LBA
information, and they are always the same.

A great step would be a formatting tool where you can specify the disk
geometry so that it will match the BIOS on the target machine.

You would need a partitioning tool as well. If you need formatting tool only for some reason then you can use format /? for help
about following switches.
/T:Tracks
/N:Sectors.

Best regards,
Slobodan

 

[Johannes Stratmann]

thanks for your reply,

Actually this is not an interesting thing since windows do not use disk

geometry (CHS) information but instead it always uses LBA

information, and they are always the same.

my experience is that LBA is not the same on different BIOS Versions (f.e.
General Software vs. Award vs. disk.sys). The c/h/s entries in the partition
table are different when I create a partition on the CF with my laptop and
CF adapter or when I create a partition when the CF is in target machine.

You would need a partitioning tool as well. If you need formatting tool

only for some reason then you can use format /? for help

about following switches.
/T:Tracks
/N:Sectors.

these options are for floppy disks (and from the time where an OS fitted on
a floppy disk).

Best regards,
Slobodan

thanks, Johannes

 

[Slobodan Brcin \(eMVP\)]

Hi Johannes,

CHS this is disk geometry information. Today because of big disks (They can't be described by limited size registers) and other
compatibility reasons nobody use it any more but rather all BIOS-es use L-CHS which is BIOS specific.

LBA is and must be always same.
For instance LBA sector 0 is always MBR, and logical sectors position is absolute on disk so sector 1 is next, etc regardless of
disk geometry.
Also disk based on its capacity have fixed number of sectors and if BIOS if not faulty last sector you can access at LBA position
that matches number of sectors minus 1.
L-CHS is completely different story since counting changes from BIOS to BIOS.

these options are for floppy disks (and from the time where an OS fitted on
a floppy disk).

Perhaps but these values are written to BPB and still used by ntldr. during the boot.
If you don't place MBR but format disk itself values written by these switches alone are Disk Geometry.

If you are interested in what is stored in MBR sector (partition tables).
http://www.ata-atapi.com/hiwtab.htm

If you want to see what format store in BPB:
http://www.microsoft.com/resources/...Windows/XP/all/reskit/en-us/prkd_tro_ilxl.asp

Best regards,
Slobodan