On Wed, Dec 22, 2010 at 11:20 PM, Chirag Anand <anand.chi...@gmail.com>wrote:
> On Dec 22 10:43PM, Rajveer Singh wrote: > > Hello Guys, > > > > I've a confusion related to hard drive detection process by system BIOS. > > This question may sound strange to some of you but I'll appreciate if I > can > > get any link or lead to explore it further. > > > > As all of us know, to detect hardrive, we must need a suitable driver for > > hard disk in kernel. When we buy a new hard drive, if it's driver is not > in > > the kernel, it doesn't detect but system BIOS can read it's MBR. So I'm > just > > wondering, What machenism or techniques are used by BIOS so it doesn't > > require any additional drivers to detect hard drives. > > Talking about programming, the BIOS first reads the 1 sector of any hard > disk by a BIOS interrupt 0x80 and tries to locate the byte "0xAA55" at > the 512th byte, which confirms that the starting 512 bytes are bootable > code. > > So, if your hard disk is detected inside the BIOS, I think it will be > able to do the above procedure. After the kernel is loaded, the generic > drivers for IDE/SATA etc. should do the needful. > > According to me, there is no need for drivers at the BIOS level, they > are only required while/after the kernel is loaded. > Thanks guys for your quick responses, Yes, I agree, drivers for disk(IDE/SATA/SCSI/SAS chipsets, thanks to Mahesh for correcting me) are required by kernel not by BIOS but I'm wondering, why BIOS doesn't need drivers to access it. What special techniques are used in BIOS, so it can detect disks without it's drivers. If it's true, why kernel can not use the same technique to detect the new disks. Thanks, Rajveer Singh _______________________________________________ Ilugd mailing list Ilugd@lists.linux-delhi.org http://frodo.hserus.net/mailman/listinfo/ilugd
