**************************************** * LUG meet on 12 Jan. 2003 @ VJTI ****************************************
On Wed, 8 Jan 2003, Nikhil Joshi wrote: > Now BIOS performs the IO checks. Afterwards it searches for address > (Track 0) of a media (CDROM/HDD/FDD). Now it is expected that Track 0 > contains valid OS. (Some Magic Number AFAIK) > > Now where does the Bootloader come into picture? ( I dunno pls someone > elucidate on this) After BIOS finishes the POST, it checks the Master Boot Record on the boot devices in configured order (configurable in newer bioses). Control is passed to the first MBR with executable code on it. In the case of DOS/Windows, this simply has a JMP instruction to go to the boot sector of the active partition (this is set in the partition table). In the case of boot loaders, it is a JMP instruction to the boot loader image - wherever on the hard disk it may be. If you configured your lilo to be on the boot sector of some partition, then you would have to make that partition active for control to be passed to it. This is more or less how things happen. I'm sure someone else can give a more technical explanation. If you're interested, get a hold of a disk editor and browse the raw disk. Philip -- Illiterate? Write today, for free help! -- _______________________________________________ http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
