vsm

commit f4b4e02a65bc63d5eff03cc76fe7da43a369856d
parent 9aa5f22ab7c94e120b62bb59015924bd89c2c535
Author: glenda <glenda@9front.local>
Date:   Fri, 11 Feb 2022 21:48:22 +0000

map boilerplate funcions for future new memory model

Diffstat:
A
mem.c
 | 
50
++++++++++++++++++++++++++++++++++++++++++++++++++
M
mkfile
 | 
8
+++++---
M
vsm.c
 | 
33
+++++++++++++++++++++++++--------
M
vsm.h
 | 
16
++++++++++++++++

4 files changed, 96 insertions(+), 11 deletions(-)
diff --git a/mem.c b/mem.c
@@ -0,0 +1,50 @@
+#include <u.h>
+#include <libc.h>
+
+#include "vsm.h"
+
+int
+_mapget(int id, Mapentry **m)
+{
+	/* TODO: binary search */
+	int i;
+	for (i = 0; (i < mapsize) && (map[i].id <= id); i++) {
+		if (map[i].id == id) {
+			*m = map + i;
+			return i;
+		}
+	}
+	*m = nil;
+	return i;
+}
+
+void *
+mapget(int id)
+{
+	Mapentry *m;
+	_mapget(id, &m);
+	if (m != nil) return m->vp;
+	return nil;
+}
+
+void
+mapset(int id, void *vp)
+{
+	int n;
+	Mapentry *m;
+
+	n = _mapget(id, &m);
+
+	if (m != nil) {
+		m->vp = vp;
+		return;
+	}
+
+	mapsize++;
+	map = realloc(map, sizeof(Mapentry) * mapsize);
+	memcpy(map + n, map + n + 1, sizeof(Mapentry) * (mapsize - n - 1));
+	map[n].id = id;
+	map[n].vp = vp;
+
+	return;
+}
diff --git a/mkfile b/mkfile
@@ -1,10 +1,12 @@
 </$objtype/mkfile
 
-TARG=run\
-	asm
+TARG=\
+	run \
+	asm \
 
 OFILES=\
-	vsm.$O\
+	mem.$O \
+	vsm.$O \
 
 HFILES=vsm.h
 
diff --git a/vsm.c b/vsm.c
@@ -82,19 +82,27 @@ void i_FROMR(void)
 /* Memory Management: */
 void i_STORE(void)
 {
-	ram[*dsp] = *(dsp - 1);
+	mapset(*dsp, dsp - 1);
 	dsp -= 2;
 }
 
 void i_FETCH(void)
 {
-	*dsp = ram[*dsp];
+	CELL *r;
+	r = mapget(*dsp);
+	if (r != nil) *dsp = *r;
+	else *dsp = 0;
 }
 
 /* Literals: */
 void i_LIT(void)
 {
-	*(dsp + 1) = ram[pc + 1];
+	CELL *r;
+	r = mapget(pc + 1);
+	if (r != nil) *(dsp + 1) = *r;
+	else {
+		*(dsp + 1) = 0;
+	}
 	dsp++;
 	pc++;
 }
@@ -161,8 +169,6 @@ instruction instructions[128] = {
 void
 vsm_reset(void)
 {
-	//CELL i;
-	//for (i = 0; i < IMAGE_SIZE; i++) ram[i] = VSM_NOP;
 	pc = 0;
 	dsp = dstack;
 	rsp = rstack;
@@ -194,9 +200,12 @@ vsm_run(void)
 			fprint(2, "pc reached end of the image\n");
 			return;
 		}
+
 		op = ram[pc];
+
+
 		if (op >= NUM_OPS) {
-			fprint(2, "invalid op == %x\n", op);
+			fprint(2, "invalid op == %d\n", op);
 			return;
 		}
 		vsm_exec(op);
@@ -214,11 +223,19 @@ vsm_readimage(char *path)
 	if (fd <= 0) return -1;
 	mp = ram;
 	while((n = read(fd, buf, 64)) > 0){
+		if (mp + n/sizeof(CELL) >= ram + IMAGE_SIZE)
+			sysfatal("file bigger than image size");
+
 		memcpy(mp, buf, n);
 		mp += n/sizeof(CELL);
-		if (mp >= ram + IMAGE_SIZE)
-			sysfatal("file bigger than image size");
 	}
 	close(fd);
+
+	int i;
+	for (i = 0; i < IMAGE_SIZE; i++) {
+		if (ram[i] == 0) break;
+		mapset(i, ram + i);
+	}
+
 	return 0;
 }
diff --git a/vsm.h b/vsm.h
@@ -3,6 +3,22 @@
 #define STACK_DEPTH 512
 typedef void (*instruction)(void);
 
+/* Memory */
+
+typedef struct Mapentry Mapentry;
+
+struct Mapentry {
+	int id;
+	void *vp;
+};
+
+Mapentry *map;
+usize mapsize;
+
+int _mapget(int, Mapentry **);
+void * mapget(int);
+void   mapset(int, void *);
+
 /* Operators */
 
 enum {