On Sun, 1 Mar 1998, David Woodhouse wrote:
Not so. At least on the SX164 we have, it knows about the filesystem. Anyway, the phrase "the location of which is described by values stored on the first 512 byte sector" sounds suspiciously like understanding disk partitions to me.
Ahh... the Windows NT AlphaBIOS that runs on the PC164. Its a lot like the Windows NT ARC firmware, but it is not SRM.
What does reading raw sectors off of a disk have to do with partitions? Before any disk has partitions or even filesystems on it, it has sectors. Do you think the MBR is a partition? You store these values in the first 512 byte sector of raw disk and you read them.
The SRM firmware understands at least FAT, and possibly also NTFS partitions. Certainly it's capable of loading second-stage bootloaders like "LINLOAD.EXE" from a FAT floppy disk. I believe that even the emergency firmware update is managed from a FAT floppy.
Again, the Windows NT AlphaBIOS, tailored specifically for running Windows NT, has support for these filesystems. It is not SRM. I dont see the point in developing such OS specific BIOS extensions.
Making new filesystems just so that the BIOS can access them easily is not practicable. Neither is the idea of dedicating a partition to BIOS extensions. Simple read-only filesystem support can be kept fairly small, and is going to be required by UNIX people to load either the second-stage bootloader or the kernel itself.
Agreed, creating new filesystems is probably not practical. But saying that a filesystem is required in order to boot UNIX is entirely false. The concept of reading sectors directly from disk independent of partitions or filesystem is not a new one. I'd suggest that you read the SRM Firmware HOWTO:
http://www.azstarnet.com/~axplinux/srm.html
Aa.
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