emul/Makefile

@@ -15,10 +15,10 @@ $(SLATEST):
 $(BIN2C):
 	$(MAKE) -C ../tools
 
-# z80c.bin is not in the prerequisites because it's a bootstrap
-# binary that should be updated manually through make updatebootstrap.
+# z80c.bin and boot.bin are not in the prerequisites because they're bootstrap
+# binaries that should be updated manually through make updatebootstrap.
 forth/forth0.bin: $(SLATEST)
-	cp forth/z80c.bin $@
+	cat forth/boot.bin forth/z80c.bin > $@
 	$(SLATEST) $@
 	cat forth/emul.fs >> $@
 
@@ -37,7 +37,7 @@ forth/core.bin: $(FORTHSRC_PATHS) forth/stage1
 	cat $(FORTHSRC_PATHS) ./forth/stop.fs | $(STRIPFC) | ./forth/stage1 | tee $@ > /dev/null
 
 forth/forth1.bin: forth/core.bin $(SLATEST)
-	cat forth/z80c.bin forth/core.bin > $@
+	cat forth/boot.bin forth/z80c.bin forth/core.bin > $@
 	$(SLATEST) $@
 
 forth/forth1-bin.h: forth/forth1.bin $(BIN2C)
@@ -60,11 +60,10 @@ emul.o: emul.c
 	$(CC) -c -o emul.o emul.c
 
 
-forth/z80c.bin: forth/stage2
-	cat ./forth/conf.fs ../forth/xcomp.fs ./forth/xcomp.fs ../forth/boot.fs ../forth/z80c.fs ../forth/icore.fs | ./forth/stage2 | tee $@ > /dev/null
-
 .PHONY: updatebootstrap
-updatebootstrap: forth/z80c.bin
+updatebootstrap: forth/stage2
+	cat ./forth/conf.fs ../forth/boot.fs | ./forth/stage2 | tee forth/boot.bin > /dev/null
+	cat ./forth/conf.fs ../forth/xcomp.fs ./forth/xcomp.fs ../forth/z80c.fs ../forth/icore.fs | ./forth/stage2 | tee forth/z80c.bin > /dev/null
 
 .PHONY: clean
 clean:

emul/forth/xcomp.fs

@@ -1,18 +1,11 @@
-: _
-    ['] EXIT ,
-    R> DROP     ( exit : )
-    XCOFF
-; IMMEDIATE
-';' CURRENT @ 4 - C!
-
-: (find) (xfind) ;
-: ['] X['] ; IMMEDIATE
-: COMPILE XCOMPILE ; IMMEDIATE
 : CODE XCODE ;
 : IMMEDIATE XIMM ;
 : : [ ' X: , ] ;
 
 CURRENT @ XCURRENT !
+H@ ' _bend - 4 + XOFF !
 
+( dummy entry for dict hook )
+(xentry) _
 H@ 256 /MOD 2 PC! 2 PC!
-H@ XOFF !
+

forth/boot.fs

@@ -87,7 +87,6 @@ L1 BSET ( CBR )
 'E' A, 'X' A, 'E' A, 'C' A, 'U' A, 'T' A, 'E' A,
 PC L1 @ - A,, ( prev )
 7 A,
-H@ XCURRENT !        ( set current tip of dict )
 L2 BSET ( used frequently below )
     0x17 A,,         ( nativeWord )
     IY POPqq,        ( is a wordref )
@@ -367,3 +366,20 @@ PC ORG @ 0x22 + ! ( litWord )
       want... )
     RAMSTART 0x06 + LD(nn)HL, ( RAMSTART+0x06 == IP )
     JPNEXT,
+
+( filler )
+NOP, NOP, NOP, NOP, NOP,
+
+( DICT HOOK )
+( This dummy dictionary entry serves two purposes:
+  1. Allow binary grafting. Because each binary dict always
+     end with a dummy entry, we always have a predictable
+     prev offset for the grafter's first entry.
+  2. Tell icore's "_c" routine where the boot binary ends.
+     See comment there.
+)
+'_' A, 'b' A, 'e' A, 'n' A, 'd' A,
+PC L2 @ - A,, ( prev )
+5 A,
+
+H@ 256 /MOD 2 PC! 2 PC!

forth/xcomp.fs

@@ -14,29 +14,18 @@
   "'" and friends will *not* find words you're about to
   define. Only (xfind) will.
 
-  Words overrides like ":", "IMMEDIATE" and "CODE" are not
-  automatically shadowed to allow the harmless inclusion of
-  this unit. This shadowing has to take place in your xcomp
-  configuration.
+  Words ":", "IMMEDIATE" and "CODE" are not automatically
+  shadowed to allow the harmless inclusion of this unit. This
+  shadowing has to take place in your xcomp configuration.
 
   See example in /emul/forth/xcomp.fs
-
-  Note that this cross compilation unit is far from foolproof
-  and cannot cross compile any kind of code. Cross compliation
-  of Forth dicts is *tricky*. This unit is designed to cross
-  compile the core full interpreter, that is, the contents
-  of the "/forth" folder of the project.
-
-  Cross compiling anything else might work, but as soon as
-  you start defining immediates and using them on-the-fly,
-  things get icky.
 )
 
 VARIABLE XCURRENT
 VARIABLE XOFF
 
 : XCON XCURRENT CURRENT* ! ;
-: XCOFF 0x02 RAM+ CURRENT* ! ;
+: XCOFF CURRENT CURRENT* ! ;
 
 : (xentry) XCON (entry) XCOFF ;
 
@@ -44,37 +33,15 @@ VARIABLE XOFF
 
 : XIMM XCON IMMEDIATE XCOFF ;
 
-: XAPPLY
-    DUP XOFF @ > IF XOFF @ - THEN
-;
-
-( Run find in XCURRENT and apply XOFF )
-: (xfind)
-    XCURRENT @ SWAP     ( xcur w )
-    _find               ( a f )
-    IF  ( a )
-        ( apply XOFF )
-        XAPPLY 1
-    ELSE
-        0
-    THEN
-;
-
-: X' XCON ' XCOFF XAPPLY ;
-: X['] X' LITN ;
-( TODO: am I making the word "," stable here? )
-: XCOMPILE X' LITN ['] , , ;
-
 : X:
-    (xentry)
+    XCON
+    (entry)
     ( 0e == compiledWord )
     [ 0x0e LITN ] ,
     BEGIN
     ( DUP is because we need a copy in case it's IMMED )
     WORD DUP
-    ( cross compile CURRENT )
-    XCURRENT @ SWAP     ( w xcur w )
-    _find               ( w a f )
+    (find)      ( w a f )
     IF
         ( is word )
         DUP IMMED?
@@ -82,33 +49,23 @@ VARIABLE XOFF
             ( When encountering IMMEDIATE, we exec the *host*
               word. )
             DROP    ( w )
-            ( system CURRENT )
+            ( hardcoded system CURRENT )
             0x02 RAM+ @ SWAP        ( cur w )
             _find                   ( a f )
             NOT IF ABORT THEN   ( a )
-            XCON EXECUTE XCOFF
+            EXECUTE
         ELSE
             ( not an immed. drop backup w and write, with
               offset. )
             SWAP DROP   ( a )
-            XAPPLY
+            DUP 0x100 > IF XOFF @ - THEN
             ,
         THEN
     ELSE ( w a )
-        ( not found? it might be an immediate that isn't yet defined in our
-          cross-compiled dict. It's alright, we can find-and-execute it. )
-        DROP ( w )
-        ( system CURRENT )
-        0x02 RAM+ @ SWAP        ( cur w )
-        _find                   ( a f )
-        IF
-            ( found. It *must* be an IMMED )
-            DUP IMMED? NOT IF ABORT THEN
-            EXECUTE
-        ELSE
-            ( not found. maybe number )
-            (parse*) @ EXECUTE LITN
-        THEN
+        ( maybe number )
+        DROP   ( w )
+        (parse*) @ EXECUTE LITN
     THEN
     AGAIN
+    XCOFF
 ;