From d11ac3f0061c24b828557898f3cf0bee37c1dfeb Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Sat, 24 Oct 2020 22:06:51 -0400
Subject: [PATCH] emul/8086: and we have liftoff!

Getting a Collapse OS prompt.
---
 emul/8086/Makefile |  6 ++----
 emul/8086/cpu.c    |  5 +++--
 emul/8086/cpu.h    |  2 +-
 emul/8086/foo.asm  |  3 ---
 emul/8086/forth.c  |  7 ++++++-
 emul/8086/xcomp.fs | 14 ++++++++++++++
 6 files changed, 26 insertions(+), 11 deletions(-)
 delete mode 100644 emul/8086/foo.asm
 create mode 100644 emul/8086/xcomp.fs

diff --git a/emul/8086/Makefile b/emul/8086/Makefile
index 7768963..7024d87 100644
--- a/emul/8086/Makefile
+++ b/emul/8086/Makefile
@@ -13,10 +13,8 @@ forth: forth.c forth.bin $(OBJS)
 emul.o: emul.c $(BLKFS)
 	$(CC) -DFBIN_PATH=\"`pwd`/forth.bin\" -DBLKFS_PATH=\"`pwd`/$(BLKFS)\" -c -o emul.o emul.c
 
-forth.bin: foo.asm
-	nasm -o $@ foo.asm
-#forth.bin: xcomp.fs $(STAGE) $(BLKFS)
-#	$(CDIR)/stage < xcomp.fs > $@
+forth.bin: xcomp.fs $(STAGE)
+	$(CDIR)/stage < xcomp.fs > $@
 
 $(BLKFS): $(STAGE)
 
diff --git a/emul/8086/cpu.c b/emul/8086/cpu.c
index 41d6543..671a5c5 100755
--- a/emul/8086/cpu.c
+++ b/emul/8086/cpu.c
@@ -1217,13 +1217,13 @@ void intcall86(uint8_t intnum) {
 	tf = 0;*/
 }
 
-void exec86(int execloops) {
+int exec86(int execloops) {
 	int loopcount;
 	uint8_t docontinue;
 	static uint16_t firstip;
 
 	for (loopcount = 0; loopcount < execloops; loopcount++) {
-        if (hltstate) return;
+        if (hltstate) return 0;
 
         reptype = 0;
         segoverride = 0;
@@ -3393,6 +3393,7 @@ void exec86(int execloops) {
                 break;
         }
     }
+    return 1;
 }
 
 void reset86() {
diff --git a/emul/8086/cpu.h b/emul/8086/cpu.h
index dc10759..7414b10 100755
--- a/emul/8086/cpu.h
+++ b/emul/8086/cpu.h
@@ -53,5 +53,5 @@ void write86 (uint32_t addr32, uint8_t value);
 void writew86 (uint32_t addr32, uint16_t value);
 uint8_t read86 (uint32_t addr32);
 uint16_t readw86 (uint32_t addr32);
-void exec86(int execloops);
+int exec86(int execloops); // returns 0 if halted
 void reset86();
diff --git a/emul/8086/foo.asm b/emul/8086/foo.asm
deleted file mode 100644
index 8d672c4..0000000
--- a/emul/8086/foo.asm
+++ /dev/null
@@ -1,3 +0,0 @@
-mov al, 'X'
-int 1
-hlt
diff --git a/emul/8086/forth.c b/emul/8086/forth.c
index 10a9536..8c16ee9 100644
--- a/emul/8086/forth.c
+++ b/emul/8086/forth.c
@@ -19,9 +19,14 @@ void int1() {
     putchar(getreg8(regal));
 }
 
+void int2() {
+    putreg8(regal, getchar());
+}
+
 int main(int argc, char *argv[])
 {
     INTHOOKS[1] = int1;
+    INTHOOKS[2] = int2;
     reset86();
     // initialize memory
     FILE *bfp = fopen(FBIN_PATH, "r");
@@ -36,6 +41,6 @@ int main(int argc, char *argv[])
         c = getc(bfp);
     }
     fclose(bfp);
-    exec86(100);
+    while (exec86(100));
     return 0;
 }
diff --git a/emul/8086/xcomp.fs b/emul/8086/xcomp.fs
new file mode 100644
index 0000000..647576a
--- /dev/null
+++ b/emul/8086/xcomp.fs
@@ -0,0 +1,14 @@
+0xff00 CONSTANT RS_ADDR
+0xfffa CONSTANT PS_ADDR
+RS_ADDR 0x80 - CONSTANT SYSVARS
+30 LOAD   ( 8086 asm )
+262 LOAD  ( xcomp ) 270 LOAD  ( xcomp overrides )
+445 461 LOADR ( 8086 boot code )
+353 LOAD  ( xcomp core low )
+CODE (emit) AX POPx, 1 INT, ;CODE
+CODE (key) 2 INT, AH 0 MOVri, AX PUSHx, ;CODE
+380 LOAD  ( xcomp core high )
+(entry) _ ( Update LATEST ) PC ORG @ 8 + !
+EOT,
+ORG @ 256 /MOD 2 PC! 2 PC!
+H@ 256 /MOD 2 PC! 2 PC!