Use the same Exomizer code for depacking the loader and for later fil…

…e access.

Makefile

@@ -43,11 +43,13 @@ hessian.d64: loader.prg main.pak options.bin emptysave.bin savelist.bin logo.pak
 hessian.d81: hessian.d64 hessiand81.seq
 	c1541 < hessiand81.seq
 
-loader.prg: kernal.s loader.s loadsym.txt ldepack.s boot.s macros.s memory.s
+loader.prg: kernal.s loader.s loadsym.txt ldepacksym.txt ldepack.s boot.s macros.s memory.s
+	dasm ldepack.s -oloader.prg -sldepack.tbl -f3
+	symbols ldepack.tbl ldepacksym.s ldepacksym.txt
 	dasm loader.s -oloader.bin -sloader.tbl -f3
 	symbols loader.tbl loadsym.s loadsym.txt
 	pack2 loader.bin loader.pak
-	dasm ldepack.s -oloader.prg -f3
+	dasm ldepack.s -oloader.prg -sldepack.tbl -f3
 	dasm boot.s -oboot.prg
 
 sfx/pistol.sfx: sfx/pistol.ins

boot.s

@@ -2,7 +2,7 @@
 
                 include memory.s
                 include kernal.s
-                include loadsym.s
+                include ldepacksym.s
 
                 org $032a
 
@@ -13,11 +13,12 @@
 
                 rorg $080d
 
-BasicStart:     ldx #AutoStartEnd-loaderFileName-1
-Copy:           lda BasicEnd+loaderFileName-AutoStart,x ;Just need to relocate data, not code
-                sta loaderFileName,x
+BasicStart:     ldx #AutoStartEnd-AutoStart
+Copy:           lda BasicEnd-1,x
+                sta AutoStart-1,x
                 dex
-                bpl Copy
+                bne Copy
+                jmp AutoStart
 BasicEnd:
                 rend
 
@@ -43,23 +44,36 @@ ClearScreen:    sta $2000,y                     ;Use another screen as $400 is t
                 bne ClearScreen
                 lda #$84
                 sta $d018
-                ldy #38
+                ldx #38
 ShowMessage:    lda #$0f
-                sta colors+12*40,y
-                lda message-1,y
+                sta colors+12*40,x
+                lda message-1,x
                 and #$3f
-                sta $2000+12*40,y
-                dey
+                sta $2000+12*40,x
+                dex
                 bne ShowMessage
-MessageDone:
-LoadLoop:       jsr ChrIn
-                sta loaderInitEnd,y
-                iny
-                cpy #214                        ;Load 214 bytes (loader depacker)
-                bne LoadLoop
-                jmp loaderInitEnd
+MessageDone:    ldx #LoadExomizerEnd-LoadExomizer-1
+CopyToStack:    lda LoadExomizer,x              ;This code will be overwritten by loader, so copy elsewhere
+                sta $0100,x
+                dex
+                bpl CopyToStack
+                jmp $100
 
 loaderFileName: dc.b "00"
 message:        dc.b "HOLD SPACE/FIRE TO DISABLE FAST LOADER"
 
+LoadExomizer:   ldy #$00
+LoadExomizerLoop:
+                jsr ChrIn
+                sta exomizerCodeStart,y
+                iny
+                cpy #packedLoaderStart-exomizerCodeStart ;Load Exomizer
+                bne LoadExomizerLoop
+                lda #<loaderCodeStart
+                ldx #>loaderCodeStart
+                jsr LoadFile                    ;Load rest of code with Exomizer
+                inc $01                         ;Kernal back on
+                jmp loaderCodeEnd               ;Jump to InitLoader
+LoadExomizerEnd:
+
 AutoStartEnd:

ldepack.s

@@ -2,9 +2,12 @@
 
                 include kernal.s
                 include memory.s
-                include loadsym.s
 
-                org loaderInitEnd
+                org exomizerCodeStart
+
+tablBi          = depackBuffer
+tablLo          = depackBuffer + 52
+tablHi          = depackBuffer + 104
 
 ; -------------------------------------------------------------------
 ; This source code is altered and is not the original version found on
@@ -41,22 +44,76 @@
 ;   specific prior written permission.
 
 ; -------------------------------------------------------------------
+; get bits (29 bytes)
+;
+; args:
+;   x = number of bits to get
+; returns:
+;   a = #bits_lo
+;   x = #0
+;   c = 0
+;   z = 1
+;   zpBitsHi = #bits_hi
+; notes:
+;   y is untouched
+; -------------------------------------------------------------------
+get_bits:
+  lda #$00
+  sta zpBitsHi
+  cpx #$01
+  bcc bits_done
+bits_next:
+  lsr zpBitBuf
+  bne bits_ok
+  pha
+  stx loadTempReg
+  jsr GetByte
+  ldx loadTempReg
+  bcs loaderror3
+  sec
+  ror
+  sta zpBitBuf
+  pla
+bits_ok:
+  rol
+  rol zpBitsHi
+  dex
+  bne bits_next
+bits_done:
+  rts
 
-Depacker:
-  ldx #3
-  ldy #0
+loaderror3:
+  pla
+  pla
+  pla
+loaderror:
+  rts
+
+        ; Load file packed with Exomizer 2 forward mode
+        ;
+        ; Parameters: A,X load address, fileNumber
+        ; Returns: C=0 if loaded OK, or C=1 and error code in A (see GetByte)
+        ; Modifies: A,X,Y
+
+LoadFile:       sta zpDestLo
+                stx zpDestHi
+                jsr OpenFile
+
+; -------------------------------------------------------------------
+; init zeropage, x and y regs.
+;
 init_zp:
-  jsr getbyte
-  sta zpBitBuf-1,x
-  dex
-  bne init_zp
+  jsr GetByte
+  ;bcs loaderror  ;Error will be caught later
+  sta zpBitBuf
+  ldy #0
 
 ; -------------------------------------------------------------------
 ; calculate tables
 ; x and y must be #0 when entering
 ;
 nextone:
-  inx
+  ldx #1
   tya
   and #$0f
   beq shortcut    ; start with new sequence
@@ -86,23 +143,29 @@ shortcut:
   iny
   cpy #52
   bne nextone
+
+begin:
   ldy #$ff
 
 ; -------------------------------------------------------------------
 ; decruncher entry point, needs calculated tables
 ;
 getgamma:
-  iny
-begin:
-  inx
-  jsr bits_next
+  lsr zpBitBuf
+  bne norefill
+  jsr GetByte
+  bcs loaderror
+  sec
   ror
+  sta zpBitBuf
+norefill:
+  iny
   bcc getgamma
-  tya
   bne sequence
 
 literal:
-  jsr getbyte
+  jsr GetByte
+  ;bcs loaderror ;Error will be caught later
   sta (zpDestLo),y
   inc zpDestLo
   bne begin
@@ -112,7 +175,7 @@ inchi:
 
 sequence:
   cpy #$11
-  beq ready   ; gamma = 17   : end of file
+  beq eof   ; gamma = 17   : end of file
 
 ; -------------------------------------------------------------------
 ; calculate length of sequence (zp_len)
@@ -167,65 +230,35 @@ copy_next:
   cpy zpLenLo
   bne copy_next
   tya
-  ldy #$00
   clc
   adc zpDestLo
   sta zpDestLo
   bcc begin
   bcs inchi
 
-ready:
-  jmp InitLoader
-
-; -------------------------------------------------------------------
-; get bits (29 bytes)
-;
-; args:
-;   x = number of bits to get
-; returns:
-;   a = #bits_lo
-;   x = #0
-;   c = 0
-;   z = 1
-;   zpBitsHi = #bits_hi
-; notes:
-;   y is untouched
-; -------------------------------------------------------------------
-get_bits:
-  lda #$00
-  sta zpBitsHi
-  cpx #$01
-  bcc bits_done
-bits_next:
-  lsr zpBitBuf
-  bne bits_ok
-  pha
-  jsr getbyte
-  sec
-  ror
-  sta zpBitBuf
-  pla
-bits_ok:
-  rol
-  rol zpBitsHi
-  dex
-  bne bits_next
-bits_done:
-  rts
-
-getbyte:
-  stx loadTempReg
-  jsr ChrIn
-  ldx loadTempReg
+eof:
+  clc
   rts
 
 tablBit:        dc.b 2,4,4                      ;Exomizer static tables
 tablOff:        dc.b 48,32,16
 
-tablBi          = *
-tablLo          = * + 52
-tablHi          = * + 104
+; -------------------------------------------------------------------
+; end of decruncher
+; -------------------------------------------------------------------
+
+OpenFile:       rts
+                dc.b 0,0
+SaveFile:       rts
+                dc.b 0,0
+GetByte:        lda #$36
+                sta $01
+                cli
+                jsr ChrIn
+                sei
+                dec $01
+                clc
+                rts
 
-                dc.b >mainCodeStart             ;This will be read next from the file
-                dc.b <mainCodeStart
+packedLoaderStart:
                 incbin loader.pak

ldepacksym.txt

@@ -0,0 +1,5 @@
+GetByte
+OpenFile
+SaveFile
+LoadFile
+packedLoaderStart