Thanks Glen for the in-depth description.
All make sense, but I am still at a loss. 1. The boot bios is enabled. 2. SCSI device is on ID0. 3. SCSI runs fine once linux is loaded from a floppy. So it is damb weird. The is detected ok, but the BIOS fails to see an OS. Matt At Wednesday, 26-06-02 15:18 (+0930), Glen Turner wrote: >Matt Hyne wrote: >>I have been having trouble getting a machine to boot lilo (or anything >>from HDD) after an install of RH7.3. >>Lilo is installed (and I ran it again for good measure) but the only way >>I can get linux to boot is to use the boot floppy I created at install time. > >LILO is a 16-bit program which only uses BIOS services. So issues >like Linux support for the SCSI driver don't enter into the picture >at that stage of the boot process. > >Your SCSI card should contain a boot BIOS, this is detected by the >motherboard's BIOS when the machine boots. The motherboard BIOS will >call the SCSI card's BIOS to spin up the drive as the machine boots. >You should see the disk lights flash. > >Later the motherboard BIOS will go looking for a bootable drive, >it will start with the motherboard (IDE) drives and, if there is >no bootable drive on that controller, try each of the controllers >on the ISA/PCI bus. The SCSI controller's BIOS will provide the >motherboard BIOS with facilities to di disk I/O -- in this case >to read the partition table and the boot block. > >LILO should be loaded from that boot block. LILO will use calls >to the motherboard BIOS to do disk I/O. If the LILO's I/O request >refers to the SCSI drive then the motherboard BIOS will call the >SCSI controller BIOS to satisfy that I/O request. > >LILO will load the Linux image, and then jump to a particular >address in that image. Linux will then be running in 16-bit >mode. It will move to 32-bit mode, at which stage the 16-bit >BIOS calls are no longer accessible and Linux had better have >a 32-bit device driver 'module' for your SCSI controler handy >(usually in initrd, a initial RAM drive loaded by LILO along >with the Linux image). > > ------- > >Since when Linux boots from the floppy and can access the SCSI >disk we can assume that the SCSI controllr device driver module >exists and works. > >So the most likely cause of failures from your description are: > > - The SCSI controller's BIOS is not activated. You usually > do this by pressing a magic key chord during the boot process, > which enters a configuration dialogue. The option might > be called "boot BIOS" or "boot ROM". You want it on. You > can only turn this on for one SCSI controller in your system. > > - Your controller actually has a DIP socket for a boot ROM, > but no boot ROM is in the socket. This is only likely > if your controller is old. > > - You have exceeded the BIOS limitations on searching for > a bootable drive. You can only boot from the first two > motherboard devices or the first two controller devices. > So if you have a SCSI bus with 3 disks, the bootable disk > had better not be the last SCSI disk discovered by the > SCSI controller -- you influence the disk discover order > by using the SCSI ID. > >All this assumes that you have no SCSI issues. Note the SCSI >bus settings from the running Linux system. Configure the SCSI >controller BIOS to have the same settings. > >Regards, >Glen > -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
