# HG changeset patch
# User boisy
# Date 1129029025 0
# Node ID c96f594fe0989156ee58e05041ec5c891c42dfe9
# Parent  a9154d83aff9f46ed59fb8c503c2626b75c5bd39
Added fragmented boot support... needs additional testing.

diff -r a9154d83aff9 -r c96f594fe098 level1/modules/boot_1773.asm
--- a/level1/modules/boot_1773.asm	Wed Sep 21 11:09:41 2005 +0000
+++ b/level1/modules/boot_1773.asm	Tue Oct 11 11:10:25 2005 +0000
@@ -22,6 +22,9 @@
 *
 *   6r4    2004/02/17  Rodney Hamilton
 * Minor optimizations, improvements in source comments
+*
+*   7      2005/10/10  Boisy G. Pitre
+* Added fragmented bootfile support
 
          nam   Boot
          ttl   WD1773 Boot module
@@ -72,18 +75,20 @@
 
 tylg     set   Systm+Objct
 atrv     set   ReEnt+rev
-rev      set   $04
-edition  set   6
+rev      set   $00
+edition  set   7
 
          mod   eom,name,tylg,atrv,start,size
 
 * NOTE: these are U-stack offsets, not DP
+seglist  rmb   2						pointer to segment list
+blockloc rmb   2                       pointer to memory requested
+blockimg rmb   2                       duplicate of the above
+bootloc  rmb   3                       sector pointer; not byte pointer
+bootsize rmb   2                       size in bytes
 drvsel   rmb   1
-buffptr  rmb   2
 currtrak rmb   1
-*ddfmt    rmb   1
 ddtks    rmb   1		no. of sectors per track
-*ddtot    rmb   1
 dblsided rmb   1
 side     rmb   1		side 2 flag
 size     equ   .
@@ -91,32 +96,156 @@
 name     fcs   /Boot/
          fcb   edition
 
-start    clra			clear A
-         ldb   #size		get our 'stack' size
-MakeStak pshs  a		save 0 on stack
-         decb			and continue...
-         bne   MakeStak		until we've created our stack
+start    orcc  #IntMasks  ensure IRQs are off (necessary?)
+         leas  -size,s   
+         tfr   s,u        get pointer to data area
+         pshs  u          save pointer to data area
+                         
+* Device Specific Init
+         lbsr  HWInit    
+*         bcs   error2    
+                         
+* Request memory for LSN0
+         ldd   #256       get sector/fd buffer
+         os9   F$SRqMem   get it!
+         bcs   error2    
+         bsr   getpntr    restore U to point to our statics
+                         
+* Read LSN0
+         clrb             MSB sector
+         ldx   #0         LSW sector
+         lbsr  HWRead     read LSN 0
+         bcs   error      branch if error
+                         
+         ifgt  Level-1   
+         lda   #'0        --- loaded in LSN0'
+         jsr   <D.BtBug   ---
+         endc            
+                         
+* Pull relevant values from LSN0
+         lda   DD.TKS,x    number of tracks on this disk
+         sta   ddtks,u 
+         lda   DD.FMT,x    disk format byte
+         sta   dblsided,u 
+         lda   DD.BT,x    os9boot pointer
+         sta   bootloc,u 
+         ldd   DD.BT+1,x  LSW of 24 bit address
+         std   bootloc+1,u
+         ldd   DD.BSZ,x   os9boot size in bytes
+         std   bootsize,u
+         beq   FragBoot   if zero, do frag boot
+* Old style boot -- make a fake FD segment
+         leax  FD.SEG,x  
+         addd  #$00FF		round up to next page
+         exg   a,b
+         std   FDSL.B,x   save file size
+         lda   bootloc,u 
+         sta   FDSL.A,x  
+         ldd   bootloc+1,u
+         std   FDSL.A+1,x save LSN of file (contiguous)
+         clr   FDSL.S,x   make next segment entry 0
+         clr   FDSL.S+1,x
+         clr   FDSL.S+2,x
+         ldd   bootsize,u
+         bra   GrabBootMem
+                         
+Back2Krn ldx   blockimg,u pointer to start of os9boot in memory
+         clrb             clear carry
+         ldd   bootsize,u
+error2   leas  2+size,s   reset the stack    same as PULS U
+         rts              return to kernel
+                         
+* Error point - return allocated memory and then return to kernel
+error                    
+* Return memory allocated for sector buffers
+         ldd   #256      
+         ldu   blockloc,u
+         os9   F$SRtMem  
+         bra   error2    
+                         
+* Routine to save off alloced mem from F$SRqMem into blockloc,u and restore
+* the statics pointer in U
+getpntr  tfr   u,d        save pointer to requested memory
+         ldu   2,s        recover pointer to data stack
+         std   blockloc,u
+ret      rts             
+                         
+* NEW! Fragmented boot support!
+FragBoot ldb   bootloc,u  MSB fd sector location
+         ldx   bootloc+1,u LSW fd sector location
+         lbsr  HWRead     get fd sector
+         ldd   FD.SIZ+2,x get file size (we skip first two bytes)
+         std   bootsize,u
+         leax  FD.SEG,x   point to segment table
+                         
+GrabBootMem                 
+         ifgt  Level-1   
+         os9   F$BtMem   
+         else            
+         os9   F$SRqMem  
+         endc            
+         bcs   error     
+         bsr   getpntr   
+         std   blockimg,u
+                         
+* Get os9boot into memory
+BootLoop stx   seglist,u  update segment list
+         ldb   FDSL.A,x   MSB sector location
+BL2      ldx   FDSL.A+1,x LSW sector location
+         bne   BL3       
+         tstb            
+         beq   Back2Krn  
+BL3      lbsr  HWRead    
+         inc   blockloc,u point to next input sector in mem
+                         
+         ifgt  Level-1   
+         lda   #'.        Show .'
+         jsr   <D.BtBug  
+         endc            
+                         
+         ldx   seglist,u  get pointer to segment list
+         dec   FDSL.B+1,x get segment size
+         beq   NextSeg    if <=0, get next segment
+                         
+         ldd   FDSL.A+1,x update sector location by one to 24bit word
+         addd  #1        
+         std   FDSL.A+1,x
+         ldb   FDSL.A,x  
+         adcb  #0        
+         stb   FDSL.A,x  
+         bra   BL2       
+                         
+NextSeg  leax  FDSL.S,x   advance to next segment entry
+         bra   BootLoop  
+                         
 
-         tfr   s,u		put 'stack statics' in U
-*         ldx   #DPort
-         lda   #%11010000	($D0) Force Interrupt (stops any command in progress)
-         sta   >DPort+CMDREG	write command to command register
-*         sta   CMDREG,x		write command to command register
-         lbsr  Delay2		delay 54~
-         lda   >DPort+STATREG	clear status register
-*         lda   STATREG,x	read status register
+
+************************************************************
+************************************************************
+*              Hardware-Specific Booter Area               *
+************************************************************
+************************************************************
+
+* Device Specific Init
+* HWInit - Initialize the device
+HWInit
+         ldy   Address,pcr				get hardware address
+         lda   #%11010000		($D0) Force Interrupt (stops any command in progress)
+         sta   CMDREG,y			write command to command register
+         lbsr  Delay2			delay 54~
+         lda   STATREG,y		clear status register
          lda   #$FF
-         sta   currtrak,u	set current track to 255
-         leax  >NMIRtn,pcr	point to NMI routine
+         sta   currtrak,u		set current track to 255
+         leax  >NMIRtn,pcr		point to NMI routine
          IFGT  Level-1
-         stx   <D.NMI		save address
+         stx   <D.NMI			save address
          ELSE
-         stx   >D.XNMI+1	save address
+         stx   >D.XNMI+1		save address
          lda   #$7E
          sta   >D.XNMI
          ENDC
          lda   #MOTON+BootDr	turn on drive motor
-         sta   >DPort+CONTROL
+         sta   CONTROL,y
 
 * MOTOR ON spin-up delay loop (~307 mSec)
          IFGT  Level-1
@@ -136,80 +265,8 @@
          ENDC
          subd  #$0001
          bne   L003A
-
-* search for memory to use as a sector buffer
-         pshs  u,y,x,b,a	save regs
-         ldd   #SECTSIZE	get sector size in D
-         os9   F$SRqMem		request that much memory
-         bcs   L00AA		branch if there is an error
-         tfr   u,d		move pointer to D temporarily
-         ldu   $06,s		restore U (saved earlier)
-         std   buffptr,u	save alloced mem pointer in statics
-         clrb
-
-* go get LSN0
-         ldx   #$0000		we want LSN0
-         bsr   ReadSect		go get it
-         bcs   L00AA		branch if error
+		 rts
 
-* From LSN0, we get various pieces of info.
-*         ldd   DD.TOT+1,y
-*         std   ddtot,u
-         lda   <DD.FMT,y	get format byte of LSN0
-*         sta   ddfmt,u		save it for ???
-         anda  #FMT.SIDE	keep side bit
-         sta   dblsided,u	and save it
-         lda   DD.TKS,y		get sectors per track
-         sta   ddtks,u		and save
-         ldd   <DD.BSZ,y	get bootfile size
-         std   ,s		save on stack
-         ldx   <DD.BT+1,y	get start sector of bootfile
-         pshs  x		push on the stack
-         ldd   #SECTSIZE	load D with sector size
-         ldu   buffptr,u	and point to the buffer pointer
-         os9   F$SRtMem		return the memory
-         ldd   $02,s		get the bootfile size
-         IFGT  Level-1
-         os9   F$BtMem
-         ELSE
-         os9   F$SRqMem		get the memory from the system
-         ENDC
-         puls  x		pull bootfile start sector off stack
-         bcs   L00AA		branch if error
-         stu   2,s		save pointer to bootfile mem on stack
-         stu   8+buffptr,s	also save to buffptr,u
-         ldu   6,s		reload original U
-*         ldd   2,s		get pointer to bootfile mem
-*         std   buffptr,u	and save pointer
-         ldd   ,s		get bootfile size
-         beq   L00A3		branch if zero
-
-* this loop reads a sector at a time from the bootfile
-* X = start sector
-* D = bootfile size
-L0091    pshs  x,b,a		save params
-         clrb
-         bsr   ReadSect		read sector
-         bcs   L00A8		branch if error
-         IFGT  Level-1
-         lda   #'.		dump out a period for boot debugging
-         jsr   <D.BtBug		do the debug stuff     
-         ENDC
-         puls  x,b,a		restore params
-* RVH NOTE: the next 3 lines assume sector size=256=LSN size?
-         inc   buffptr,u	point to next 256 bytes
-         leax  1,x		move to next sector
-         subd  #SECTSIZE	subtract sector bytes from size
-         bhi   L0091		continue if more space
-L00A3    clrb
-         puls  b,a
-         bra   L00AC
-L00A8    leas  $04,s
-L00AA    leas  $02,s
-L00AC    puls  u,y,x
-         leas  size,s		clean up stack
-         clr   >DPort+CONTROL	shut off floppy disk
-         rts
 
 L00B7    lda   #DDEN+MOTON+BootDr	permit alternate drives
          sta   drvsel,u			save drive selection byte
@@ -219,14 +276,20 @@
          ldb   #0+STEP		RESTORE cmd
          lbra  L0195
 
+*
+* HWRead - Read a 256 byte sector from the device
+*   Entry: Y = hardware address
+*          B = bits 23-16 of LSN
+*          X = bits 15-0  of LSN
+* 		   blockloc,u = ptr to 256 byte sector
+*   Exit:  X = ptr to data (i.e. ptr in blockloc,u)
+*
 * Read a sector from the 1773
-* Entry: X = LSN to read
-ReadSect lda   #$91
-         cmpx  #$0000		LSN0?
-         bne   L00DF		branch if not
+* Entry: B,X = LSN to read
+HWRead   lda   #$91
          bsr   L00DF		else branch subroutine
          bcs   L00D6		branch if error
-         ldy   buffptr,u	get buffer pointer in Y for caller
+         ldx   blockloc,u	get buffer pointer in X for caller
          clrb
 L00D6    rts
 
@@ -242,12 +305,12 @@
          bne   L00D7
 L00EA    bsr   L013C
          bcs   L00D6		if error, return to caller
-         ldx   buffptr,u	get address of buffer to fill
+         ldx   blockloc,u	get address of buffer to fill
          orcc  #IntMasks	mask interrupts
-         pshs  y		save Y
-         ldy   #$FFFF
+         pshs  x			save X
+         ldx   #$FFFF
          ldb   #%10000000	($80) READ SECTOR command
-         stb   >DPort+CMDREG	write to command register
+         stb   CMDREG,y		write to command register
          ldb   drvsel,u		(DDEN+MOTORON+BootDr)
 * NOTE: The 1773 FDC multiplexes the write precomp enable and ready
 * signals on the ENP/RDY pin, so the READY bit must always be ON for
@@ -256,7 +319,7 @@
          tst   side,u		are we on side 2?
          beq   L0107
          orb   #SIDESEL		set side 2 bit
-L0107    stb   >DPort+CONTROL
+L0107    stb   CONTROL,y
          lbsr  Delay2		delay 54~
          orb   #HALTENA		HALT enable ($80)
 *         lda   #%00000010	RESTORE cmd ($02)
@@ -268,13 +331,14 @@
 *         sta   >DPort+CONTROL
 *         puls  y
 *         bra   L0138
-         stb   >DPort+CONTROL
+         stb   CONTROL,y
          nop
          nop
-         bra   L0123
+*         bra   L0123
 
+         ldx   ,s			get X saved earlier
 * Sector READ Loop
-L0123    lda   >DPort+DATAREG	read from WD DATA register
+L0123    lda   DATAREG,y	read from WD DATA register
          sta   ,x+
 *         stb   >DPort+CONTROL
          nop
@@ -286,13 +350,13 @@
 * use a polled I/O loop instead.
 
 NMIRtn   leas  R$Size,s		adjust stack
-         puls  y
-         ldb   >DPort+STATREG	read WD STATUS register
-         bitb  #$9C		any errors?
+         puls  x
+         ldb   STATREG,y	read WD STATUS register
+         bitb  #$9C			any errors?
 *         bitb  #$04		LOST DATA bit set?
          beq   RetOK		branch if not
 *         beq   ChkErr		branch if not
-L0138    comb			else we will return error
+L0138    comb				else we will return error
          ldb   #E$Read
 RetOK    rts
 
@@ -302,7 +366,7 @@
          tfr   x,d
          cmpd  #$0000
          beq   L016C
-         clr   ,-s		clear space on stack
+         clr   ,-s			clear space on stack
          tst   dblsided,u	double sided disk?
          beq   L0162		branch if not
          bra   L0158
@@ -318,16 +382,16 @@
 L0162    subb  ddtks,u
          sbca  #$00
          bcc   L0160
-L0168    addb  #18		add sectors per track
-         puls  a		get current track indicator off of stack
+L0168    addb  #18			add sectors per track
+         puls  a			get current track indicator off of stack
 L016C    incb
-         stb   >DPort+SECTREG	save in sector register
+         stb   SECTREG,y	save in sector register
 L0170    ldb   currtrak,u	get current track in B
-         stb   >DPort+TRACKREG	save in track register
+         stb   TRACKREG,y	save in track register
          cmpa  currtrak,u	same as A?
          beq   L018D		branch if so
          sta   currtrak,u
-         sta   >DPort+DATAREG
+         sta   DATAREG,y
          ldb   #$10+STEP	SEEK command
          bsr   L0195		send command to controller
          pshs  x
@@ -345,15 +409,15 @@
 *         rts
 
 L0195    bsr   L01A8		issue FDC cmd, wait 54~
-L0197    ldb   >DPort+STATREG
+L0197    ldb   STATREG,y
          bitb  #$01		still BUSY?
          bne   L0197		loop until command completes
          rts
 
 * Entry: B = command byte
 L019F    lda   drvsel,u
-         sta   >DPort+CONTROL
-         stb   >DPort+CMDREG
+         sta   CONTROL,y
+         stb   CMDREG,y
          rts
 
 * issue command and wait 54 clocks
@@ -383,9 +447,12 @@
 
          IFGT  Level-1
 * Filler to get $1D0
-Filler   fill  $39,$1D0-3-*
+Filler   fill  $39,$1D0-3-2-1-*
          ENDC
 
+Address  fdb   DPort
+WhichDrv fcb   0
+
          emod
 eom      equ   *
          end