[CentOS] how to find out which is the system disk by bios?

Mon Aug 6 15:13:57 UTC 2007
Farkas Levente <lfarkas at bppiac.hu>

hi,
how can i know which is the system disk by bios? i've pc with 2 sata
disk connected to the on board sata controller and 2 other connected to
a pci card sata controller. bios see all disk as well as linux, but in
linux kernel sda and sdb is the pci card's 2 disks and the on board
controllers are sdc and sdd. my problem is centos install the system by
default to sda and intall grub in the system disk's mbr (ie. sda's mbr).
which is right most of the time, but in my case the system is not boot
after the install since grub (and the os) it's not on the system disk
where the bios try to find it. ok after i recognize it i can choose sdc
during install and install the whole system there, but the worse thing
is that i'd like to do it from a kickstart file _automaticaly_. so i
have to somehow discover which disk will be choosen by the bios as
system disk? or which disk is connected to the on board controller and
which is the pci extension card? how can i find out this information
(eg. by a shell script in kickstart %pre section)? and this scripts
should have to work for all kind of motherboard and sata card too:-)
thanks.

-- 
  Levente                               "Si vis pacem para bellum!"