From billt@pongo74.West.Sun.COM Wed Jun 29 16:19 PDT 1994 Return-Path: Received: from Eng.Sun.COM (zigzag) by bigfry.Eng.Sun.COM (5.0/SMI-SVR4) id AA05410; Wed, 29 Jun 1994 16:19:05 +0800 Received: from sac.Eng.Sun.COM by Eng.Sun.COM (4.1/SMI-4.1) id AA11494; Wed, 29 Jun 94 16:20:38 PDT Received: from benet.Eng.Sun.COM by sac.Eng.Sun.COM (5.0/SMI-SVR4) id AA10333; Wed, 29 Jun 1994 16:20:25 +0800 Received: from Eng.Sun.COM (engmail1) by benet.Eng.Sun.COM (4.1/SMI-4.1) id AA01566; Wed, 29 Jun 94 16:20:19 PDT Received: from West.Sun.COM (west.West.Sun.COM) by Eng.Sun.COM (4.1(1/24/94)/SMI-4.1) id AA23160; Wed, 29 Jun 94 16:20:28 PDT Received: from cypress.West.Sun.COM by West.Sun.COM (5.0/SMI-5.3) id AA08087; Wed, 29 Jun 1994 16:20:24 +0800 Received: from pongo.West.Sun.COM (pongo74) by cypress.West.Sun.COM (4.1/SMI-4.1-900117) id AA26347; Wed, 29 Jun 94 16:20:23 PDT Received: from olds.West.Sun.COM by pongo.West.Sun.COM (5.0/SMI-SVR4) id AA23259; Wed, 29 Jun 1994 16:20:23 +0800 Received: by olds.West.Sun.COM (5.x/SMI-SVR4) id AA01511; Wed, 29 Jun 1994 16:20:19 -0700 Date: Wed, 29 Jun 1994 16:20:19 -0700 From: billt@pongo74.West.Sun.COM (Bill Taylor) Message-Id: <9406292320.AA01511@olds.West.Sun.COM> To: psarc-materials@benet.Eng.Sun.COM Subject: 1994/196 PowerPC Header Files - follow up X-Sun-Charset: US-ASCII Content-Type: text Content-Length: 2166 X-Lines: 44 Status: RO PSARC 1994/196 PowerPC Header Files Report on issue 9 from inception review. Bill Taylor @ West This note breifly describes how booting works on PowerPC with regard to the disk label(s) needed by the firmware. There are two points of discussion here, the first being the current method of booting (Method 1), and the second being booting with Open Firmware (Method 2). The discussion is limited to booting from SCSI hard disk and CDs (and not floppies). Both methods of booting rely on a x86 compatible FDISK table in sector 0 of the drive. Method 1 looks for a new "PowerPC" type partition (system id field is 0x41). If it is not found, the drive is not bootable. If it is found, the firmware looks at the second sector in the partition (defined by the "relsect" and "numsect" of the type 0x41 partition) to read a two word boot descriptor (size of the boot program, and its entry point). From this descriptor, the firmware can load the boot program into memory, and then transfer control. At the current time there is no residual information, and no callback capabilities, so the boot program is completely on its own. In summary, we are currently using a type 0x41 partition to store our boot program, and we use a type 130 (Solaris) for the Solaris slices (the same as on x86). Method 2 uses Open Firmware for PowerPC (which does not yet exist). I describe my understanding of what the Open Firmware will do (please pardon me if my terminology is not 100% correct). Open Firmware will look for a "FAT 12" partition type which will contain a DOS file system. By default, a file name "boot.elf" (a PowerPC ELF file) will be loaded as a boot client. Control is tranferred to this program along with a callback function pointer (and possibly other information). We have not fully defined what "boot.elf" will be for Solaris. This will be covered in a separate PSARC case. One new problem this FAT-12 DOS file system presents to Solaris is that there now becomes a need to a PCFS mkfs utility. At least it seems to me that there will be a need for such a utility during system installation. I think this will become a new 1-pager.