From 80891d7ec172bc22e5dc7594b1b87dbdea92ffdb Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Fri, 3 Apr 2020 08:31:30 -0400
Subject: [PATCH] Add in-memory bootstrapping system

This should help with the bootstrapping of non-emulated environment.
For example, I have a problem with the RC2014: I can't send it
bootstrap info until the ACIA is up. I need to find a way...
---
 emul/Makefile       |  11 ++++++-----
 emul/forth/emul.fs  |  21 ++++-----------------
 emul/forth/run.fs   |   1 +
 emul/forth/z80c.bin | Bin 1741 -> 1720 bytes
 forth/icore.fs      |  17 +++++++++++++----
 forth/notes.txt     |  37 ++++++++++++++++++++++++++++++++++++-
 6 files changed, 60 insertions(+), 27 deletions(-)
 create mode 100644 emul/forth/run.fs

diff --git a/emul/Makefile b/emul/Makefile
index 54270c4..3b2e0ac 100644
--- a/emul/Makefile
+++ b/emul/Makefile
@@ -1,7 +1,7 @@
 TARGETS = runbin/runbin forth/forth
 # Those Forth source files are in a particular order
 FORTHSRCS = core.fs str.fs parse.fs readln.fs fmt.fs z80a.fs
-FORTHSRC_PATHS = ${FORTHSRCS:%=../forth/%}
+FORTHSRC_PATHS = ${FORTHSRCS:%=../forth/%} forth/run.fs
 OBJS = emul.o libz80/libz80.o
 SLATEST = ../tools/slatest
 
@@ -16,6 +16,7 @@ $(SLATEST):
 forth/forth0.bin: $(SLATEST)
 	cat forth/boot.bin forth/z80c.bin > $@
 	$(SLATEST) $@
+	cat forth/emul.fs >> $@
 
 forth/forth0-bin.h: forth/forth0.bin
 	./bin2c.sh KERNEL < forth/forth0.bin | tee $@ > /dev/null
@@ -24,13 +25,13 @@ forth/stage1: forth/stage.c $(OBJS) forth/forth0-bin.h
 	$(CC) forth/stage.c $(OBJS) -o $@
 
 forth/stage1dbg: forth/stage.c $(OBJS) forth/forth0-bin.h 
-	$(CC) -DDEBUG -DBOOT forth/stage.c $(OBJS) -o $@
+	$(CC) -DDEBUG forth/stage.c $(OBJS) -o $@
 
 forth/core.bin: $(FORTHSRC_PATHS) forth/stage1
 	cat $(FORTHSRC_PATHS) ./forth/stop.fs | ./forth/stage1 | tee $@ > /dev/null
 
-forth/forth1.bin: forth/forth0.bin forth/core.bin $(SLATEST)
-	cat forth/forth0.bin forth/core.bin > $@
+forth/forth1.bin: forth/core.bin $(SLATEST)
+	cat forth/boot.bin forth/z80c.bin forth/core.bin > $@
 	$(SLATEST) $@
 
 forth/forth1-bin.h: forth/forth1.bin
@@ -56,7 +57,7 @@ emul.o: emul.c
 .PHONY: updatebootstrap
 updatebootstrap: forth/stage2
 	cat ./forth/conf.fs ../forth/boot.fs | ./forth/stage2 | tee forth/boot.bin > /dev/null
-	cat ./forth/conf.fs ../forth/z80c.fs forth/emul.fs ../forth/icore.fs | ./forth/stage2 | tee forth/z80c.bin > /dev/null
+	cat ./forth/conf.fs ../forth/z80c.fs ../forth/icore.fs | ./forth/stage2 | tee forth/z80c.bin > /dev/null
 
 .PHONY: clean
 clean:
diff --git a/emul/forth/emul.fs b/emul/forth/emul.fs
index 0f4607b..245a80b 100644
--- a/emul/forth/emul.fs
+++ b/emul/forth/emul.fs
@@ -1,17 +1,4 @@
-( Implementation fo KEY and EMIT in the emulator
-  stdio port is 0
-)
-
-CODE EMIT
-    HL POPqq,
-    chkPS,
-    A L LDrr,
-    0 OUTnA,
-;CODE
-
-CODE KEY
-    0 INAn,
-    H 0 LDrn,
-    L A LDrr,
-    HL PUSHqq,
-;CODE
+HERE @ 256 /MOD 2 PC! 2 PC!
+: EMIT 0 PC! ;
+: KEY 0 PC@ ;
+CURRENT @ 12 RAM+ !
diff --git a/emul/forth/run.fs b/emul/forth/run.fs
new file mode 100644
index 0000000..7dccc06
--- /dev/null
+++ b/emul/forth/run.fs
@@ -0,0 +1 @@
+: INIT (c<$) INTERPRET ;
diff --git a/emul/forth/z80c.bin b/emul/forth/z80c.bin
index 1cfc35a2d4fa61b1609410783ab827d884ab5af0..c5137a6351623c1ed6e4b68909661fc84e03b846 100644
GIT binary patch
delta 657
zcmX|8J!lj`7=5!dJG(h@dx_u?E)q6J#GDBzLJD<Ja9D65Y%c2t4lF_lA)PES5K;wy
zny^KR<;oOV*{PkK*hnm_1Hu(n*X6JkA%5TPX|co3d*8hGz3=;8|5X2QLr!gO*YMJV
zkBgb#?pybL@l>`~m2I$?ZS6hZx!Jh_m+2Z9d>kgB2gQIY0ke@LVVq9GVazJA^^GVU
z7Xi)Uo4hWzijkb1?vuiUI)sN;%7;L|m{kjnzMY|kkznN9IxAu|fAtMvHQcp)00sl%
zCh)O%t->c~_7^K7^JCI7!4xd^oh08>o>1v>gXIId8ObO2bZ!N<kyO6i;&O&}$0R!j
z#Wj1;KGXy8wTSGwBW3^84a?9|W=mXWxVYqQC>D=q=h^<=VdoZyW;HmURb?hHv<8Ch
z{)i#jrm{=l(8~2YUER2mC{Dwqn}q2@On88Esxr(_41uO?jwlDmreE2EizN~`K@UGJ
z$#^^H+^)vIUPc~>19GZ5^}!hHKU!N$7r3lF-eL!*Y9yA3<aYiQ5=(j|RgKWdHll+#
zN(sxznr$_0X5TSbjncSVS^LO!t_|+h@xsF$hsToZDn^r*)%yQf5#FOkRvG5qD#iU3
Re&^G+a{Wt=guy0l?JrIYdv5>$

delta 704
zcmYjPJ!lhQ7=FI{zPn3Ga<PI|qe2YPCZ(u@KNyRGp9db+oSs)3r$$PtlO8pTg9H`l
z47a#sbd+;6lZZHJCy|1Z!9fC23{E-}^nG&~I^1#J^FHtMKHu}+oBU?}^{hPYUiZQr
z)C|6F9>L?!cwfXd_f7$F2H$WT4}K7^vYN+J2PK?1xSkzlcH(ogyjV3gs?ptzhih}S
zy~uER3JhL#1J{9KK#c*t6a;P~oQBPqF~)8#dEtZv)Z>@(n0Ow4l!vDKq;N40;ozAn
zL7*T1k(EN<j8Mc#FtTNA$8+lFz7K>=;k;1-pfR9Y7GL6)a&K*$?~I6szalNYum=Xu
z&C%RYc8NM)VEGoEwB$E?+A><EmPDT~GM(Y|Ns%YE;=iie=~)Bu(@M29xoP6pKaFKS
zxN<nXuR}9TyI^S2<hHaSA{yJ|DrL5IzrFFOc9PTJF%|o*N?iyHje%evJ7P$FLfNKg
zXe8Dri%*^Q*rL}6-QY&xhL@0aP_cU|!U4LVK%MGc`l3YXtBDMJYU`qjujKQx?}w+@
zXL+)>8hUCZe4-Mvy1+-iTaF0y3yh0tY!gDK!jy<)SyE8|Wq1uQ+yz<$zOXeGy|8gF
z&7_3HN-T|f9#0(HwmFByN^S3_wH0?MCRUSHnwmbFNo`*^!+j;%TQ0GF%aPDnp#}a2
D$Lx_6

diff --git a/forth/icore.fs b/forth/icore.fs
index 9299a36..c82be2c 100644
--- a/forth/icore.fs
+++ b/forth/icore.fs
@@ -189,13 +189,22 @@
     AGAIN
 ;
 
+( system c< simply reads source from binary, starting at
+  LATEST. Convenient way to bootstrap a new system. )
+: (c<)
+    ( 51 == SYSTEM SCRATCHPAD )
+    0x51 _c RAM+ _c @   ( a )
+    _c DUP _c C@        ( a c )
+    _c SWAP 1 _c +      ( c a+1 )
+    0x51 _c RAM+ _c !   ( c )
+;
+
 : BOOT
     LIT< (parse) _c (find) _c DROP _c (parse*) _c !
-    LIT< (c<) _c (find) _c
-    NOT IF LIT< KEY _c (find) _c DROP THEN
+    ( 51 == SYSTEM SCRATCHPAD )
+    _c CURRENT _c @ 0x51 _c RAM+ _c !
     ( 0c == CINPTR )
-    0x0c _c RAM+ _c !
-    LIT< (c<$) _c (find) IF EXECUTE ELSE _c DROP THEN
+    LIT< (c<) _c (find) _c DROP 0x0c _c RAM+ _c !
     LIT< INIT _c (find)
     IF EXECUTE
     ELSE _c DROP _c INTERPRET THEN
diff --git a/forth/notes.txt b/forth/notes.txt
index f178961..a685068 100644
--- a/forth/notes.txt
+++ b/forth/notes.txt
@@ -88,7 +88,8 @@ RAMSTART   INITIAL_SP
 +0e        WORDBUF
 +2e        SYSVNXT
 +4e        INTJUMP
-+51        RAMEND
++51        SYSTEM SCRATCHPAD
++60        RAMEND
 
 INITIAL_SP holds the initial Stack Pointer value so that we know where to reset
 it on ABORT
@@ -113,3 +114,37 @@ INTJUMP All RST offsets (well, not *all* at this moment, I still have to free
 those slots...) in boot binaries are made to jump to this address. If you use
 one of those slots for an interrupt, write a jump to the appropriate offset in
 that RAM location.
+
+SYSTEM SCRATCHPAD is reserved for temporary system storage.
+
+*** Initialization sequence
+
+On boot, we jump to the "main" routine in boot.fs which does very few things.
+It sets up the SP register, CURRENT and HERE to LATEST (saved in stable ABI),
+then look for the BOOT word and calls it.
+
+In a normal system, BOOT is in icore and does a few things:
+
+1. Find "(parse)" and set "(parse*)" to it.
+2. Find "(c<)" a set CINPTR to it (what C< calls).
+3. Write LATEST in SYSTEM SCRATCHPAD ( see below )
+4. Find "INIT". If found, execute. Otherwise, execute "INTERPRET"
+
+On a bare system (only boot+icore), this sequence will result in "(parse)"
+reading only decimals and (c<) reading characters from memory starting from
+CURRENT (this is why we put CURRENT in SYSTEM SCRATCHPAD, it tracks current
+pos ).
+
+This means that you can put initialization code in source form right into your
+binary, right after your last compiled dict entry and it's going to be executed
+as such until you set a new (c<).
+
+Note that there is no EMIT in a bare system. You have to take care of supplying
+one before your load core.fs and its higher levels.
+
+Also note that this initialization code is fighting for space with HERE: New
+entries to the dict will overwrite that code! Also, because we're barebone, we
+can't have comments. This leads to peculiar code in this area. If you see weird
+whitespace usage, it's probably because not using those whitespace would result
+in dict entry creation overwriting the code before it has the chance to be
+interpreted.