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550 lines
21 KiB
Plaintext
550 lines
21 KiB
Plaintext
;
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; File: SCSIBoot.a
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;
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; Contains: This is the SCSI boot code for the Macintosh.
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;
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; Written by: Erich Ringewald
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;
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; Copyright: © 1985-1993 by Apple Computer, Inc. All rights reserved.
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;
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; Change History (most recent first):
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;
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; <SM9> 10/14/93 pdw Comment changes.
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; <SM8> 5/29/93 PW Added line to heap munging code (after driver is called) that
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; updates TheZone as well as ApplZone.
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; <SM7> 2/13/93 PW Added <LW2> change.
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; <LW2> 2/11/93 PW Added ability to tell drivers not to munge the heap by passing a
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; flag register (D6) from StartSearch or LateLoad.
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; <SM6> 11/3/92 SWC Changed SCSIEqu.a->SCSI.a.
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; <SM5> 10/22/92 CSS Change some branch short instructions to branches.
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; <SM4> 6/2/92 kc Roll in Pandora/Horror/Zydeco changes. Comments follow:
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; <H2> 12/21/91 jmp (BG,Z3) Added fix for busy status from drive while spinning up.
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; <Z2> 10/2/90 CCH Added a cache flush after SCSI reads during boot.
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; <SM1> 5/22/92 CS Cyclone (Pandora) roll in.
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; <9> 5/1/92 JSM Don’t use onMacXX style conditionals. This file now has no
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; conditionals.
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; <8> 12/27/91 RB Changed the flush cache code for 040's so it calls CacheFlush
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; <7> 9/16/91 JSM Cleanup header.
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; <6> 6/12/91 LN Changed #include 'HardwareEqu.a' to 'HardwarePrivateEqu.a'
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; <5> 9/21/90 BG Removing EclipseNOPS and other 040-related kludges as 040s are
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; now working more reliably.
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; <4> 7/19/90 BG Added EclipseNOPs for flakey 040s.
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; <3> 6/22/90 CCH Added a data cache push for 68040's after a SCSI block read.
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; <2> 5/16/90 MSH Added hasPowerControls to hcmac conditional.
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; <1.4> 8/22/89 SES Removed references to nFiles.
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; <1.3> 5/26/89 GGD Deleted the hack that was added for flakey PRAM on MvMac in
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; December.
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; <1.2> 12/13/88 rwh Added hack to set default OS to Mac OS while MvMac PRAM is
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; flakey.
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; <1.1> 11/10/88 CCH Fixed Header.
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; <1.0> 11/9/88 CCH Adding to EASE.
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; <•1.2> 9/23/88 CCH Got rid of inc.sum.d and empty nFiles
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; <1.1> 4/18/88 CSL Added support for JVC drive for HcMac
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; <1.0> 2/10/88 BBM Adding file for the first time into EASE…
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; <C895> 9/30/87 MSH Port to HcMac (Laguna)
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; <C859> 6/15/87 SHF Fixed bug in register usage in SRead routine.
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; <C846> 4/28/87 SHF Bug fixes.
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; <C770> 2/7/87 SHF Fixed bug in SRead read retry (stack problem).
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; <C613> 1/12/87 SHF Fixed driver count decrement size (long to word).
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; <C608> 1/9/87 SHF Fixed register-usage bug for booting non-Mac drivers.
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; <C478> 12/11/86 SHF Changes for Becks to allow booting a non-Mac OS.
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; <A382> 11/8/86 SHF Took out checksum bypass for driver checksums of 0.
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; <A349> 11/4/86 SHF Made the error-handling more forgiving (especially for 532-byte
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; sectors).
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; <A311> 10/31/86 SHF Added checksum for drivers having the appropriate boot code
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; partition map entry; we now search for appropriate driver
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; partition map entries and data partition map entries.
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; <A300> 10/29/86 SHF Go through all 8 devices (InitSCSIMgr sets the bit in SCSIDrvrs
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; corresponding to the CPU's SCSI id).
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; <A244> 10/27/86 SHF Read 512 instead of 256 bytes of blocks 0 and 1.
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; <A211> 10/17/86 SHF Put the Status phase check after the Command trap, added retry
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; to accomodate Unit Attention devices.
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; <C185> 9/30/86 SHF Fixed the mask value for the Status phase check.
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; <C165> 9/29/86 SHF Checks for Status phase after bad Select.
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; <C136> 9/3/86 SHF Added explicit .b, .w, .l; now checks NewPtr value
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; <C66> 7/9/86 SHF Fixed zero sbDrvrCount field bug in 'Openit'
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; <C26> 5/29/86 SHF Deleted _SCSIReset call in SCSILoad to avoid Unit Attn
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; recurrence. InitIO in StartInit now does the reset.
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; <C1> 4/15/86 RDC Deleted old MidMac changes
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; 2/19/86 BBM Made some modifications to work under MPW
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; 1/16/86 ELR Fixed polarity of beq to bpl for tst of SCSI byte.
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; 10/28/85 ELR Fixed bug in SCSILoad which didn't correctly look at SCSIFlags
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; 10/27/85 ELR Removed inclusion of SCSIMacs and SCSIBootEqu; this is now
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; included in NewEqu.
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; 10/27/85 ELR Added Flag "SCSIDrvrs" which is a bitmap for loaded SCSI
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; drivers. Now SCSILoad can be called repeatedly to check for new
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; devices coming online. A call to SCSILoad was placed in the
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; RDBootBlocks loop in StartInit to facilitate this.
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; 9/27/85 ELR Bunch of changes in a last ditch effort to get something to
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; work.
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; 9/16/85 RDC More changes for MidMac
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; 9/13/85 RDC Added changes for Milwaukee (MidMac) Fixed SetTrapaddress call
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; to work with new ROM's Added include of HWequ.text
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; 9/6/85 ELR New Today.
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;
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BLANKS ON
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STRING ASIS
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PRINT OFF
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LOAD 'StandardEqu.d'
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INCLUDE 'HardwarePrivateEqu.a'
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INCLUDE 'SCSI.a'
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PRINT ON
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MACHINE MC68020
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;
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; Equates for the partition map blocks
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;
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PMSigWord EQU $504D ; offset 0
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map_blks EQU 4 ; see partition design document
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part_phys_blk EQU 8
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part_blks EQU 12
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name EQU 16
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type EQU 48
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boot_size EQU 96
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boot_cksum EQU 116
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SCSIBoots PROC EXPORT
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EXPORT SCSILoad ; this is called by startinit
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;---------------------------------------------------------------
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;
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; SCSILoad -- loads in SCSI device drivers. Called by the start code.
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;
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; Modified to handle arbitrary combinations of requested drivers. <A349/03Nov86>
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;
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; On entry, d0.b is a bit map of devices for which we want to load drivers.
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; D6 = mask to OR with D5 when calling driver's installation point
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; On exit, d0.b is a bit map of devices for which we either:
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;
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; (a) successfully loaded drivers - or -
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; (b) the device(s) didn't respond and it would be useful to try
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; them later (possibly when they are powered up, etc.).
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;
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; If a device responded to the select but didn't have a valid driver, then
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; we clear the bit associated with that SCSI ID so that we don't waste any
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; more time polling it.
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;
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; --------------------------------------
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;
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; For NuMac only....
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;
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; d3 contains the following fields taken from parameter RAM in StartSearch.a:
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;
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; bits 0-7: partition number
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; bits 8-15: device ID (used for slots)
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; bits 16-23: OS type to boot (normally Mac OS)
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; bits 24-31: reserved
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;
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SCSILoad
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btst.b #7,HWCfgFlags ; is there a SCSI chip? <A349/03Nov86>
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bne.s Start ; yes, so continue <A349/03Nov86>
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moveq.l #0,d0 ; 0: don't try any more devices <A349/03Nov86>
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rts ; <A349/03Nov86>
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; deleted old code <C1/15Apr86>
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; Start the load procedure. Assumes the SCSI bus has already been reset
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; <C26/29May86>; makes a pass through the 7 SCSI devices,
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; attempting to load 0-7 drivers. On entry, d0 has a bit map (byte wide)
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; of drivers to attempt to load. We compare this with the list of drivers
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; already loaded in order to decide which ones to load now. <A311/31Oct86>
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; InitSCSIMgr has already set the SCSIDrvrs bit corresponding to the CPU's
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; SCSI bus ID.
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Start
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movem.l a0-a6/d1-d7,-(sp) ; don't clobber this stuff
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move.b d0,-(sp) ; save the map <A311>
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; hard reset of the SCSI bus removed here <C26/29May86>
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; start command to portable drives removed here
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moveq.l #7,d5 ; start with SCSI device 7 <A300>
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CheckNext
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btst.b d5,(sp) ; do we want this one? <A311>
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beq.s @1 ; nope <A311>
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btst.b d5,SCSIDrvrs ; is it already loaded? <A349/04Nov86>
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bne.s @1 ; yes, so skip it <A349/04Nov86>
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bsr.s OpenIt ; try to install the driver
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beq.s @1 ; don't clear bit in map <A349/04Nov86>
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; If the return value is non-zero, then it means a drive was there but that
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; block 0 or 1 (or the driver's checksum) weren't cool. In this case we
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; clear the bit in the map to be returned to the caller. <A349/04Nov86>
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bclr.b d5,(sp) ; don't try this one again <A349/04Nov86>
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@1
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dbra d5,CheckNext ; do the next one
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moveq.l #0,d0 ; clear upper nonsense <A349/04Nov86>
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move.b (sp)+,d0 ; pop the map byte <A311>
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movem.l (sp)+,a0-a6/d1-d7 ; restore everything else
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tst.w d0 ; set con. codes for word <A349/04Nov86>
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rts
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;---------------------------------------------------------------
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;
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; OpenIt. This routine solicits the SCSI device whose ID is in d5
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; for a driver. If one is found, it is loaded into the system heap
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; and given an installation call. d3 contains boot information
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; passed in by StartSearch.a.
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;
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;
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; Equates for the local stack frame <A311>
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;
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DriverStart EQU -4 ; 1st blk # of driver (long)
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DriverBlks EQU DriverStart-4 ; # of blks in driver (long)
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BootOS EQU DriverBlks-2 ; boot OS type (word)
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MapCnt EQU BootOS-4 ; # of part. map blocks (long)
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CurMapBlk EQU MapCnt-4 ; counter variable (long)
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BlockBuf EQU CurMapBlk-512 ; after link, EA = 0(sp)
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FrameSize EQU BlockBuf ; value for link instruction
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OpenIt
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move.l d3,-(sp) ; preserve register <C478>
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link a6,#FrameSize ; need some locals <A311>
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move.l sp,a2 ; start of blk buffer <A311>
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swap d3 ; OS type (low byte) <C478>
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moveq.l #0,d0 ; clear upper bits <C478>
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move.b d3,d0 ; get the byte <C478>
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move.w d0,BootOS(a6) ; store as a word <C478>
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moveq.l #0,d3 ; d3 gets block location
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moveq.l #1,d2 ; d2 gets block count
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move.w #512,d4 ; d4 gets block size <A244>
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bsr SRead ; read the block from unit in d5
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bne.w ZeroExit ; OK to try later <A349/04Nov86>
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cmpi.w #SBSigWord,SBSig(sp) ; is it for real?
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bne.w NonZeroExit ; no -- don't try again <A349/04Nov86>
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move.w SBBlkSize(sp),d4 ; get the block size
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move.w SBDrvCount(sp),d0 ; get the driver count
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beq NonZeroExit ; no drivers: no retry <A349/04Nov86><SM5> CSS
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lea SBDrvrs(sp),a0 ; point at driver list
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move.l SBData(sp),d7 ; save the default data block pointer...
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NextDD
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move.w BootOS(a6),d1 ; desired driver type <C608>
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cmp.w DDType(a0),d1 ; is this the one? <C608>
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beq.s FoundDD
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addq.l #DDLen,a0 ; move to the next driver
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subq.w #1,d0 ; decrement count <C613>
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bne.s NextDD
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bra NonZeroExit ; no matching drivers... <A349/04Nov86><SM5> CSS
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FoundDD
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bset.b d5,SCSIDrvrs ; show we tried to load the driver
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move.l DDBlock(a0),d3 ; block #
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move.l d3,DriverStart(a6) ; save a local copy <A311>
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moveq.l #0,d2 ; clear high word <A311>
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move.w DDSize(a0),d2 ; # blocks
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move.l d2,DriverBlks(a6) ; local copy <A311>
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move.l d4,d0 ; block size of driver
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mulu d2,d0 ; times # blocks is byte size
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_NewPtr ,SYS ; head for the system heap
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bne.s NonZeroExit ; no room in the inn <A349/04Nov86>
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move.l a0,a3 ; put the driver here
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move.l a0,a2
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bsr SRead ; load the driver
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bne.s DisposExit ; deallocate on error <A349/04Nov86>
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moveq.l #1,d3 ; now read block 1
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move.l d3,CurMapBlk(a6) ; initialize counter <A311>
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moveq.l #1,d2 ; do a single block
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move.w #512,d4 ; full block <A244>
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move.l sp,a2 ; ontop of block 0 is OK
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bsr SRead ; preserves a2
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bne.s DisposExit ; error in read of block 1
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cmp.w #SBMac,BootOS(a6) ; are we booting Mac OS? <C478>
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bne.s CallDriver ; no, so skip partition stuff <C478>
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cmp.w #PDSigWord,(a2) ; old partition map? <A311>
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beq.s CallDriver ; yes, so just call it <A311>
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; Just in case someone defines a new signature word for block 1, we'll
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; be nice and assume that the driver knows how to handle this new type.
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cmp.w #PMSigWord,(a2) ; new partition entry? <A311>
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bne.s CallDriver ; no, so be nice <A311>
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move.l map_blks(a2),d0 ; get count of map blocks <A311>
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move.l d0,MapCnt(a6) ; and save it locally
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bra.s DoNewPartition ; go do everything else
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CallDriver
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move.l a2,a0 ; pointer to the partition block
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; We assume that if the driver is for the Mac OS, it will install itself and return.
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; If it's another OS type (such as UNIX), it should take control of the machine
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; and never return.
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; <LW2>pdw thru next
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or.l D6, D5 ; OR in control mask from client
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jsr (a3) ; install the driver...
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and.l #$00FFFFFF, D5 ; get rid of bit(s) that were in D6
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; Make the System Heap growable by making the App Heap and TheZone the same zone as the System.
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MOVE.L SysZone,A0 ; which zone is the system zone
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MOVE.L A0,TheZone ; make THE REAL zone that zone
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MOVE.L A0,ApplZone ; good-bye to the app zone (make it same zone)
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MOVE.L bkLim(A0),HeapEnd ; end of System heap is now end of App Heap.
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; <LW2>pdw from prev
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ZeroExit
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moveq.l #0,d0 ; assume success <A349/04Nov86>
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bra.s OpenItRts ; <A349/04Nov86>
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DisposExit
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move.l a3,a0 ; restore ptr to driver <A349/04Nov86>
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_DisposPtr ; get rid of bad driver <A349/04Nov86>
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NonZeroExit
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moveq.l #-1,d0 ; bad sig or checksum <A349/04Nov86>
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OpenItRts
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unlk a6 ; clean up <A311>
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move.l (sp)+,d3 ; restore register <C478>
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tst.w d0 ; set con. codes <C545>
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rts
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;---------------------------------------------------------------
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;
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; DoNewPartition -- This is called when the signature word on block 1
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; matches the new partition map signature value. The first task is to
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; look for the partition map block for the driver itself (which contains a
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; checksum field, among other things). After we find one that matches the
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; Mac driver information we found in block 0, we do a checksum on the
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; driver (this helps to avoid loading garbage or trashed drivers, which
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; will cause a sad Mac at bootup time). If the checksum is good, we try
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; to find the first HFS partition entry in the partition map. If we pass
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; all these stages, then we finally call the driver.
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;
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DoNewPartition ; new subroutine <A311>
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cmp.l #'Appl',type+0(a2) ; 'Apple_Driver' type?
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bne.s NextMapEntry
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cmp.l #'e_Dr',type+4(a2)
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bne.s NextMapEntry
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cmp.l #'iver',type+8(a2)
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bne.s NextMapEntry
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cmp.l #'Maci',name+0(a2) ; 'Macintosh' name?
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bne.s NextMapEntry ; only check 4 letters
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move.l DriverStart(a6),d0 ; starting block of driver
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cmp.l part_phys_blk(a2),d0 ; same driver from block 0?
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bne.s NextMapEntry ; starts somewhere else...
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move.l a3,a0 ; pointer to driver
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move.l boot_size(a2),d1 ; size of driver (bytes)
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bsr DoCksum ; put checksum in d0
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cmp.l boot_cksum(a2),d0 ; matches saved value?
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beq.s CkSumOK ; yes, so continue
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bra.s DisposExit ; else remove driver <A349/04Nov86>
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NextMapEntry
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addq.l #1,CurMapBlk(a6) ; increment to next map block
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move.l CurMapBlk(a6),d3 ; get updated value
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cmp.l MapCnt(a6),d3 ; greater than maximum?
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bhi.s CksumOK ; if so, just look for data partition
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moveq.l #1,d2 ; read 1 block (from blk d3)
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move.w #512,d4 ; block size
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bsr.s SRead ; preserves a2 (ptr to block)
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bne.s NextMapEntry ; error in read
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cmp.w #PMSigWord,(a2) ; new partition entry?
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bne.s NextMapEntry ; try another if not
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bra.s DoNewPartition ; try to use this one
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; We have validated this partition map entry as belonging to a Macintosh
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; driver, and it has a good checksum (or none at all). Now we'll scan the
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; list of partition map blocks again, this time looking for the first
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; Macintosh HFS partition. If we find one, we'll load it, and call the
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; driver, passing a pointer to it. If we don't find an HFS partition,
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; then we deallocate the driver and continue with the next drive.
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CkSumOK
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moveq.l #0,d0 ; prime the loop variable
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move.l d0,CurMapBlk(a6) ; save it
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LookForDataPt
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addq.l #1,CurMapBlk(a6) ; increment to next map block
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move.l CurMapBlk(a6),d3 ; get updated value
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cmp.l MapCnt(a6),d3 ; greater than maximum?
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bhi.w DisposExit ; if so, we give up
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moveq.l #1,d2 ; read 1 block (from blk d3)
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move.w #512,d4 ; block size
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bsr.s SRead ; preserves a2 (ptr to block)
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bne.s LookForDataPt ; error in read
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cmp.w #PMSigWord,(a2) ; new partition entry?
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bne.s LookForDataPt ; try another if not
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cmp.l #'Appl',type+0(a2) ; 'Apple_HFS' type?
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bne.s LookForDataPt
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cmp.l #'e_HF',type+4(a2)
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bne.s LookForDataPt
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cmp.b #'S',type+8(a2)
|
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bne.s LookForDataPt
|
||
bra.w CallDriver ; finally got a data partition
|
||
|
||
|
||
;------------------------------------------------------------------
|
||
;
|
||
; Read block. d3 is block. d2 is block count. d4 is blocksize. d5 is unit.
|
||
; a2 is the transfer address. d6 used for a pointer into the stack.
|
||
; d7 is as follows: bit 31 is a retry flag, d7.w is the error code. <A349/04Nov86>
|
||
;
|
||
|
||
SRead
|
||
move.l d6,-(sp) ; save d6 <LW2>pdw
|
||
move.l d7,-(sp) ; save d7 <A349/04Nov86>
|
||
moveq.l #0,d7 ; clear flag & errcode <A349/04Nov86>
|
||
swap d2 ; save block count <C846>
|
||
move.w d4,d2 ; block size to LSW <C846>
|
||
SReadAgain
|
||
lea Scratch8,a0
|
||
move.b #8,(a0)+ ; read command
|
||
|
||
swap d3
|
||
andi.b #$1F,d3 ; isolate disk address
|
||
move.b d3,(a0)+ ; LUN and disk address
|
||
swap d3
|
||
|
||
move.w d3,(a0)+ ; disk address
|
||
|
||
move.l d2,d4 ; block count & size <C846>
|
||
swap d4 ; block count in low word
|
||
move.b d4,(a0)+ ; block count (byte) <C859>
|
||
clr.b (a0)+ ; cmdbyte
|
||
|
||
mulu.w d2,d4 ; size (d2) * count (d4) = total bytes
|
||
|
||
sub.w #(SCSIZE*2),sp ; make room for 2 commands...
|
||
move.l sp,d6 ; save this pointer...
|
||
|
||
subq.l #2,sp ; space for return value
|
||
_SCSIGet
|
||
move.w (sp),d7 ; error condition? <A349/04Nov86>
|
||
bne RdDone ; go report it <A349/04Nov86>
|
||
|
||
move.w d5,-(sp) ; selid
|
||
_SCSISelect
|
||
move.w (sp),d7 ; error condition? <A349/04Nov86>
|
||
bne RdDone ; go report it <A349/04Nov86> <SM5> CSS
|
||
|
||
pea Scratch8
|
||
move.w #6,-(sp) ; count
|
||
_SCSICmd
|
||
move.w (sp),d7 ; remember the result <A349/04Nov86>
|
||
bne.s Compl ; try to clean up <A349/04Nov86>
|
||
|
||
move.l d6,a0 ; point at command block
|
||
move.w #SCINC,(a0)+ ; read command
|
||
move.l a2,(a0)+ ; to this address
|
||
move.l d4,(a0)+ ; this many bytes
|
||
move.w #SCSTOP,(a0) ; then stop
|
||
|
||
move.l d6,-(sp) ; pass a pointer to this thing
|
||
|
||
_SCSIRead ; we'll save the error, <A349/04Nov86>
|
||
move.w (sp),d7 ; but still do completion
|
||
|
||
Compl
|
||
pea Scratch8 ; address for status byte
|
||
pea Scratch8+2 ; address for message byte
|
||
move.l #OneSecTicks,-(sp) ; wait up to one sec
|
||
_SCSIComplete
|
||
tst.w d7 ; error before complete? <A349/04Nov86>
|
||
beq.s ChkComplErr ; no, so continue <C846>
|
||
cmp.w #scPhaseErr,d7 ; phase error? <C846>
|
||
beq.s ChkStat ; yes, so check status <C846>
|
||
|
||
;
|
||
; Ignore SCSIComplete's phase error because it means it had <A349/04Nov86>
|
||
; to read extra bytes beyond the 512 requested to get to the
|
||
; Status phase. In the case of 532-byte sector sizes, we'll
|
||
; get this error each time during boot, so we want to ignore
|
||
; it. Note: the Mac+ SCSIMgr code doesn't signal this error.
|
||
;
|
||
ChkComplErr
|
||
move.w (sp),d7 ; check Complete ret code <A349/04Nov86>
|
||
cmp.w #scComplPhaseErr,d7 ; an error to ignore? <A349/04Nov86>
|
||
bne.s RdDone ; only ignore phase errors <A349/04Nov86>
|
||
ChkStat
|
||
move.w Scratch8,d7 ; SCSI command status byte
|
||
beq.s RdDone ; no error <A349/04Nov86>
|
||
|
||
cmp.w #2,d7 ; 'check condition' or 'busy' status? <H2>
|
||
beq.s @ChkOrBsy ; ...check condition <H2>
|
||
cmp.w #8,d7 ; ...busy condition <H2>
|
||
bne.l RdDone ; we got neither condition...bail <H2>
|
||
|
||
@ChkOrBsy
|
||
bset.l #31,d7 ; have we done a retry? <A349/04Nov86>
|
||
bne.s RdDone ; yes, so return <C770/07Feb87>
|
||
add.w #(SCSIZE*2)+2,sp ; clean up for retry... <C770/07Feb87>
|
||
bra.w SReadAgain ; try 1 more time only <C770/07Feb87>
|
||
|
||
RdDone
|
||
jsr ([jCacheFlush]) ; flush the cache <Z2>
|
||
|
||
add.w #(SCSIZE*2)+2,sp ; remove TIB and return value
|
||
move.w d7,d0 ; return error code <A349/04Nov86>
|
||
move.l (sp)+,d7 ; restore old d7 <A349/04Nov86>
|
||
move.l (sp)+,d6 ; restore old d6 <LW2>pdw
|
||
|
||
tst.w d0 ; test return value <A349/04Nov86>
|
||
rts
|
||
|
||
|
||
;-----------------------------------------------
|
||
;
|
||
; Checksum routine added <A311/31Oct86>. It uses the algorithm in the
|
||
; partition design document. On entry, a0 points to the driver and d1
|
||
; has the size in bytes (word quantity).
|
||
;
|
||
; Returns 16-bit checksum in d0. Destroys d1,d7,a0.
|
||
;
|
||
|
||
DoCksum
|
||
moveq.l #0,d0 ; initialize sum register
|
||
moveq.l #0,d7 ; zero-extended byte
|
||
bra.s CkDecr ; handle 0 bytes <A349/04Nov86>
|
||
CkLoop
|
||
move.b (a0)+,d7 ; get a byte
|
||
add.w d7,d0 ; add to checksum
|
||
rol.w #1,d0 ; and rotate
|
||
CkDecr
|
||
dbra d1,CkLoop ; next byte
|
||
tst.w d0 ; convert a checksum of 0
|
||
bne.s @1 ; into $FFFF (as per
|
||
subq.w #1,d0 ; algorithm description).
|
||
@1
|
||
rts
|
||
|
||
|
||
END
|
||
|