On 1/6/06, Sven Luther <sven.luther at wanadoo.fr> wrote: > On Fri, Jan 06, 2006 at 03:28:21PM +0200, Cyril Plisko wrote: > > > > > > What is important is that the OF client interface is still active and can > > > be > > > used from the client program (namely OpenSolaris here). This is the way > > > the > > > linux kernel early startup does it, in his prom.c code, and the way both > > > yaboot and grub2 access the disk underneath. > > > > > > grub2 really only provides OF-like capabilities to hardware lacking such, > > > and > > > in the OF implementation case, it mostly just passes down his read > > > accesses to > > > the lower level. > > > > What makes the GRUB2 so attractive is that it makes us independent from > > ufsboot. > > Indeed, i understand that. But if the pegasos OF had an ufs driver of the > level of the ufsboot one, this would also free you from the ufsboot thingy, > no ?
Yes, and at the same time will require us to implement ATA driver (in any form) right away. > > > It fetches the ramdisk image into the memory and runs from there. Which let > > us > > The OF has also the ability to load and execute elf binaries. That is true and very useful. Having more than one way of booting system is good. > > > have a working system even without ATA disk driver. the GRUB2 itself, > > indeed, > > uses the OF-client interface to access disk (or network [coming soon]). > > Ah, grub2 has no network support yet. > > > So I am not sure we need to invest in making ufsboot work on Peg. > > Nope, probably not, but it would be interesting to have good quality ufs > drivers in the pegasos OF implementation, of the same level of those found in > usfboot. Have a look at usr/src/psm/stand/bootblks/ufs/common/boot_1275.fth and usr/src/psm/stand/bootblks/ufs/common/boot_obp.fth > > Today Pegasos firmware supports Amiga and FDISK types, right ? > > There is support for amiga RDBs, msdos FDISK, and bsd disklabels, and > filesystem support for (v)fat, ext2/3, bsd ufs, and amiga ffs, pfs and sfs. > > Currently all pegasos favour the amiga RDB partition table (basically a linked > list of partition, each partition can be upto 32bit of cylinder value size, > and each cylinder size being defined by the multiplication of two 32bit values > (sectors and heads they are traditionally called), and one 32bit value for > sector size i believe, and you can have any number of partitions in the linked > list. Also, of interest to you, there is a 32bit value usable as partition > type marker, which you would use for zfs, which is something similar to > linux's raid/md/lvm thingy. The RDB disklabel also has support for carying > filesystem drivers, a bit like Solaris uses, and now also incorporates space > for a boot program. The RDB itself can be an arbitrary number in size, upto > 32bit of sectors i think. > > Either a OpenSolaris driver can be written for this, which makes cohabitation > with other operating systems easier, and yes, i am ready to write and maintain That is important consideration. > said code, having implemented it for both libparted and yaboot. The other > solution would be for the OF to implement whatever partition table is chosen > and prefered, provided you provide us with a clear specification of the format > in question. The GPT label is described in EFI spec (http://www.intel.com/technology/efi) and parted supports it too. -- Regards, Cyril
