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Limitations
A PC ROM boot program:
any boot device is treated like a floppy
real mode (only 1mb RAM)
loads only 512 bytes
inflexible priorities
no drivers for some devices
mixing IDE and SCSI may cause problems
Notes:
The limitations of the PC boot ROM
programs are mainly due to the PC's
history. In particular, all bootable
devices are treated like floppies, and
the PC boots in real mode, which
means it can access only the first 1mb
of memory (or less). The 512 bytes
which it loads is too small.
It ought to allow more flexible
configuration; for example, you should
be able to select any disk as your main
boot device. You can't always boot
from certain devices, since the ROM
has no driver, e.g. for certain network
cards. Note also that problems may
arise when you have both IDE and
SCSI disks on the same machine.