Rewrote hello world to not use the stack

README.md

@@ -58,40 +58,43 @@ evaluxn(u, u->vframe); /* Each frame
 - `+21 -03 MULS`, signed operators have the cond flag `S`.
 
 ```
+( comment )
+
 :dev/w fff9 ( const write port )
-;i 1 ( var iterator )
 
 |0100 @RESET 
 
-	#00 ,dev/w STR              ( set dev/write to console ) 
+	#00 ,dev/w STR                        ( set dev/write to console ) 
-
+	,string                               ( add string pointer to stack )
-	@word1 "hello_world         ( len: 0x0b )
-
 	@loop
-		IOW                     ( write to device#0 )
+		DUP2 LDR IOW                         ( write pointer value to console )
-		,i LDR #01 ADD ,i STR   ( increment itr )
+		#0001 ADD2                           ( increment string pointer )
-		,i LDR                  ( a = i )
+		DUP2 LDR #00 NEQ ,loop ROT JMP? POP2 ( while *ptr!=0 goto loop )
-		,word1 ,strlen JSR      ( b = string length )
-		NEQ ,loop ROT JSR? POP^ ( a != b ? loop )
 
 BRK
 
-@strlen #0001 ADD2 LDR RTS
+@string " Hello World "                ( add string to memory )
 
 |c000 @FRAME BRK
 |d000 @ERROR BRK 
+
 |FFFA .RESET .FRAME .ERROR
 ```
 
 ## TODOs
 
+- Li1 short mode
+- Defines?
+- LDR/STR helpers
+- Keyboard example
+- PPU chr device
 - Line routine
 - On-screen debugger.
 - Auto-advance ldr?
 - Getting rid of IOR/IOW would be nice..
 - Sending from the wst to the rst, balance mode/flag?
 - Device that works like an extra memory bank
-- Draw a chr sprite.
+- [debug]Print unused labels
 
 ## Refs
 

assembler.c

@@ -33,7 +33,7 @@ Program p;
 /* clang-format off */
 
 char ops[][4] = {
-	"BRK", "NOP", "LI1", "LIX", "IOR", "IOW", "LDR", "STR",
+	"BRK", "NOP", "LIT", "LIX", "IOR", "IOW", "LDR", "STR",
 	"JMP", "JSR", "RTI", "RTS", "---", "---", "---", "---",
 	"POP", "DUP", "SWP", "OVR", "ROT", "AND", "ORA", "ROL",
 	"ADD", "SUB", "MUL", "DIV", "EQU", "NEQ", "GTH", "LTH"
@@ -43,7 +43,6 @@ int scmp(char *a, char *b) { int i = 0; while(a[i] == b[i]) if(!a[i++]) return 1
 int slen(char *s) { int i = 0; while(s[i] && s[++i]) ; return i; } /* string length */
 int sihx(char *s) { int i = 0; char c; while((c = s[i++])) if(!(c >= '0' && c <= '9') && !(c >= 'a' && c <= 'f') && !(c >= 'A' && c <= 'F')) return 0; return 1; } /* string is hexadecimal */
 int shex(char *s) { int n = 0, i = 0; char c; while((c = s[i++])) if(c >= '0' && c <= '9') n = n * 16 + (c - '0'); else if(c >= 'A' && c <= 'F') n = n * 16 + 10 + (c - 'A'); else if(c >= 'a' && c <= 'f') n = n * 16 + 10 + (c - 'a'); return n; } /* string to num */
-int cmnt(char *w, int *skip) { if(w[0] == ')') { *skip = 0; return 1; } if(w[0] == '(') *skip = 1; if(*skip) return 1; return 0; } /* comment helper */
 char *scpy(char *src, char *dst, int len) { int i = 0; while((dst[i] = src[i]) && i < len - 2) i++; dst[i + 1] = '\0'; return dst; } /* string copy */
 
 #pragma mark - Helpers
@@ -63,24 +62,12 @@ pushbyte(Uint8 b, int lit)
 void
 pushshort(Uint16 s, int lit)
 {
-	if(lit) {
+	if(lit)
-		pushbyte(0x03, 0);
+		pushbyte(0x22, 0);
-		pushbyte(0x02, 0);
-	}
 	pushbyte((s >> 8) & 0xff, 0);
 	pushbyte(s & 0xff, 0);
 }
 
-void
-pushtext(char *w)
-{
-	int i = slen(w);
-	pushbyte(0x03, 0);
-	pushbyte(slen(w), 0);
-	while(i > 0)
-		pushbyte(w[--i], 0);
-}
-
 Label *
 findlabel(char *s)
 {
@@ -156,15 +143,62 @@ makevariable(char *id, Uint16 *addr, FILE *f)
 	return makelabel(id, origin);
 }
 
+int
+skipcomment(char *w, int *cap)
+{
+	if(w[0] == ')') {
+		*cap = 0;
+		return 1;
+	}
+	if(w[0] == '(') *cap = 1;
+	if(*cap) return 1;
+	return 0;
+}
+
+int
+skipstring(char *w, int *cap, Uint16 *addr)
+{
+	if(w[0] == '"') {
+		if(*cap)
+			*addr += 1;
+		*cap = !(*cap);
+		return 1;
+	}
+	if(*cap) {
+		*addr += slen(w) + 1;
+		return 1;
+	}
+	return 0;
+}
+
+int
+capturestring(char *w, int *cap)
+{
+	if(w[0] == '"') {
+		if(*cap)
+			pushbyte(0x00, 0);
+		*cap = !(*cap);
+		return 1;
+	}
+	if(*cap) {
+		int i;
+		for(i = 0; i < slen(w); ++i)
+			pushbyte(w[i], 0);
+		pushbyte(' ', 0);
+		return 1;
+	}
+	return 0;
+}
+
 int
 pass1(FILE *f)
 {
-	int skip = 0;
+	int ccmnt = 0, cstrg = 0;
 	Uint16 addr = 0;
 	char w[64];
 	while(fscanf(f, "%s", w) == 1) {
-		if(cmnt(w, &skip))
+		if(skipcomment(w, &ccmnt)) continue;
-			continue;
+		if(skipstring(w, &cstrg, &addr)) continue;
 		if(w[0] == '@') {
 			if(!makelabel(w + 1, addr))
 				return error("Pass1 failed", w);
@@ -179,12 +213,11 @@ pass1(FILE *f)
 		else {
 			switch(w[0]) {
 			case '|': addr = shex(w + 1); break;
-			case '"': addr += slen(w + 1) + 2; break;
 			case '.': addr += 2; break;
-			case ',': addr += 4; break;
+			case ',': addr += 3; break;
 			case '+': /* signed positive */
 			case '-': /* signed negative */
-			case '#': addr += (slen(w + 1) == 2 ? 2 : 4); break;
+			case '#': addr += (slen(w + 1) == 2 ? 2 : 3); break;
 			default: return error("Unknown label in first pass", w);
 			}
 		}
@@ -196,13 +229,14 @@ pass1(FILE *f)
 int
 pass2(FILE *f)
 {
-	int skip = 0;
+	int ccmnt = 0, cstrg = 0;
 	char w[64];
 	while(fscanf(f, "%s", w) == 1) {
 		Uint8 op = 0;
 		Label *l;
 		if(w[0] == '@') continue;
-		if(cmnt(w, &skip)) continue;
+		if(skipcomment(w, &ccmnt)) continue;
+		if(capturestring(w, &cstrg)) continue;
 		/* clang-format off */
 		if(w[0] == '|') p.ptr = shex(w + 1);
 		else if((op = findopcode(w)) || scmp(w, "BRK")) pushbyte(op, 0);
@@ -214,7 +248,6 @@ pass2(FILE *f)
 		else if(w[0] == '+' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)shex(w + 1), 1);
 		else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 2) pushbyte((Sint8)(shex(w + 1) * -1), 1);
 		else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)(shex(w + 1) * -1), 1);
-		else if(w[0] == '"') pushtext(w + 1);
 		else if((l = findlabel(w + 1))) pushshort(l->addr, w[0] == ',');
 		else return error("Unknown label in second pass", w);
 		/* clang-format on */

examples/draw.usm

@@ -9,51 +9,35 @@
 |0100 @RESET
 
 	( set dev/write to screen ) 
-	,01 ,dev/w STR 
+	#01 ,dev/w STR 
 
-	,01 ,color STR
+	#01 ,color STR
 	( fill rect x y w h )
-	,0020 ,0020 ,0060 ,0040 ,fillrect JSR
+	#0020 #0020 #0060 #0040 ,fillrect JSR
 
-	,02 ,color STR
+	#02 ,color STR
 	( fill rect x y w h )
-	,0030 ,0030 ,0040 ,0060 ,fillrect JSR
+	#0030 #0030 #0040 #0060 ,fillrect JSR
 
-	,03 ,color STR
+	#03 ,color STR
 	( fill rect x y w h )
-	,0040 ,0040 ,0060 ,0040 ,fillrect JSR
+	#0040 #0040 #0060 #0040 ,fillrect JSR
 
-	,01 ,color STR
+	#01 ,color STR
 	( fill rect x y w h )
-	,00a0 ,0010 ,0020 ,0020 ,fillrect JSR
+	#00a0 #0010 #0020 #0020 ,fillrect JSR
 
-	,02 ,color STR
+	#02 ,color STR
 	( fill rect x y w h )
-	,00b0 ,0040 ,0020 ,0020 ,linerect JSR
+	#00b0 #0040 #0020 #0020 ,linerect JSR
 
-	,03 ,color STR
+	#03 ,color STR
 	( fill rect x y w h )
-	,0058 ,0028 ,0050 ,0050 ,linerect JSR
+	#0058 #0028 #0050 #0050 ,linerect JSR
 
-	,01 ,color STR
+	#01 ,color STR
 	( fill rect x y w h )
-	,0028 ,0038 ,0050 ,0030 ,linerect JSR
+	#0028 #0038 #0050 #0030 ,linerect JSR
-
-	( positive )
-	,01 ,color STR
-	+0030 ,x0 STR2 +0040 ,y0 STR2
-	+0100 ,x1 STR2 +0060 ,y1 STR2
-	,line JSR
-
-	,02 ,color STR
-	+0020 ,x0 STR2 +0010 ,y0 STR2
-	+0090 ,x1 STR2 +0070 ,y1 STR2
-	,line JSR
-
-	,03 ,color STR
-	+0010 ,x0 STR2 +0040 ,y0 STR2
-	+0070 ,x1 STR2 +0060 ,y1 STR2
-	,line JSR
 
 	,redraw JSR
 
@@ -66,9 +50,9 @@ BRK
 		,x LDR2 ,x_ STR2
 		@fillrectcol
 			( draw ) ,x_ LDR2 ,y_ LDR2 ,putpixel JSR
-			,x_ LDR2 ,0001 ADD2 ,x_ STR2 
+			,x_ LDR2 #0001 ADD2 ,x_ STR2 
 			,x_ LDR2 ,w LDR2 ,x LDR2 ADD2 LTH2 ,fillrectcol ROT JMP? POP2
-		,y_ LDR2 ,0001 ADD2 ,y_ STR2 
+		,y_ LDR2 #0001 ADD2 ,y_ STR2 
 		,y_ LDR2 ,h LDR2 ,y LDR2 ADD2 LTH2 ,fillrectrow ROT JMP? POP2
 	RTS
 
@@ -78,33 +62,13 @@ BRK
 	@linerectcol
 		( draw ) ,x LDR2 ,y_ LDR2 ,putpixel JSR
 		( draw ) ,x LDR2 ,w LDR2 ADD2 ,y_ LDR2 ,putpixel JSR
-		,y_ LDR2 ,0001 ADD2 ,y_ STR2 
+		,y_ LDR2 #0001 ADD2 ,y_ STR2 
 		,y_ LDR2 ,h LDR2 ,y LDR2 ADD2 LTH2 ,linerectcol ROT JMP? POP2
 	@linerectrow
 		( draw ) ,x_ LDR2 ,y LDR2 ,putpixel JSR
 		( draw ) ,x_ LDR2 ,y LDR2 ,h LDR2 ADD2 ,putpixel JSR
-		,x_ LDR2 ,0001 ADD2 ,x_ STR2 
+		,x_ LDR2 #0001 ADD2 ,x_ STR2 
-		,x_ LDR2 ,w LDR2 ,x LDR2 ADD2 ,0001 ADD2 LTH2 ,linerectrow ROT JMP? POP2
+		,x_ LDR2 ,w LDR2 ,x LDR2 ADD2 #0001 ADD2 LTH2 ,linerectrow ROT JMP? POP2
-	RTS
-
-@line
-	,x0 LDR2 ,x_ STR2 ,y0 LDR2 ,y_ STR2                   ( start at x0,y0 )
-	,x1 LDR2 ,x0 LDR2 ,diff16sub JSR ,dx STR2             ( int dx = abs[x1 - x0] )
-	,y1 LDR2 ,y0 LDR2 ,diff16sub JSR -0001 MULS2 ,dy STR2 ( int dy = -abs[y1 - y0] )
-	,dx LDR2 ,dy LDR2 ADDS2 ,err1 STR2                    ( int err1 = dx + dy, e2; )
-	@lineloop
-	,x_ LDR2 ,y_ LDR2 ,putpixel JSR                       ( draw )
-	@line-x
-	,err1 LDR2 +0002 MULS2 ,err2 STR2                     ( e2 = 2 * err; )
-	,err2 LDR2 ,dy LDR2 LTHS2 ,line-y ROT JMP? POP2 	  ( e2 >= dy )
-		,err1 LDR2 ,dy LDR2 ADDS2 ,err1 STR2 			  ( err1 += dy; )
-		,x_ LDR2 +0001 ADDS2 ,x_ STR2                     ( y0 += y0 < y1 ? 1 : -1; )
-	@line-y
-	,err2 LDR2 ,dx LDR2 GTHS2 ,line-end ROT JMP? POP2     ( e2 <= dx )
-		,err1 LDR2 ,dx LDR2 ADDS2 ,err1 STR2              ( err1 += dx; )
-		,y_ LDR2 +0001 ADDS2 ,y_ STR2                     ( y0 += y0 < y1 ? 1 : -1; )
-	@line-end
-	,x_ LDR2 ,x1 LDR2 NEQS2 ,lineloop ROT JMP? POP2       ( loop )
 	RTS
 
 @diff16
@@ -113,17 +77,17 @@ BRK
 RTS
 
 @redraw
-	,0000 IOW2
+	#0000 IOW2
-	,0000 IOW2
+	#0000 IOW2
-	,00 IOW
+	#00 IOW
-	,01 IOW
+	#01 IOW
 	RTS
 
 @putpixel 
 	IOW2 ( y short )
 	IOW2 ( x short )
 	,color LDR IOW  ( color byte )
-	,00 IOW  ( redraw byte )
+	#00 IOW  ( redraw byte )
 	RTS
 
 |c000 @FRAME BRK 

examples/hello.usm

@@ -1,25 +1,21 @@
-( hello world, to console )
+( comment )
 
 :dev/w fff9 ( const write port )
-;i 1 ( var iterator )
 
 |0100 @RESET 
 
-	#00 ,dev/w STR              ( set dev/write to console ) 
+	#00 ,dev/w STR                        ( set dev/write to console ) 
-
+	,string                               ( add string pointer to stack )
-	@word1 "hello_world         ( len: 0x0b )
-
 	@loop
-		IOW                     ( write to device#0 )
+		DUP2 LDR IOW                         ( write pointer value to console )
-		,i LDR #01 ADD ,i STR   ( increment itr )
+		#0001 ADD2                           ( increment string pointer )
-		,i LDR                  ( a = i )
+		DUP2 LDR #00 NEQ ,loop ROT JMP? POP2 ( while *ptr!=0 goto loop )
-		,word1 ,strlen JSR      ( b = string length )
-		NEQ ,loop ROT JSR? POP^ ( a != b ? loop )
 
 BRK
 
-@strlen #0001 ADD2 LDR RTS
+@string " Hello World "                ( add string to memory )
 
 |c000 @FRAME BRK
 |d000 @ERROR BRK 
+
 |FFFA .RESET .FRAME .ERROR

examples/test.usm

@@ -1,16 +1,21 @@
 ( comment )
 
-:const abcd
+:dev/w fff9 ( const write port )
-;byte 1
-;short 2
 
 |0100 @RESET 
 
-	12 34 ADD
+	#00 ,dev/w STR                           ( set dev/write to console ) 
-	1234 0001 ADD2
+	,string                                  ( add string pointer to stack )
+	@loop
+		DUP2 LDR IOW                         ( write pointer value to console )
+		#0001 ADD2                           ( increment string pointer )
+		DUP2 LDR #00 NEQ ,loop ROT JMP? POP2 ( while *ptr!=0 goto loop )
 
 BRK
 
+@string " Hello World "                      ( add string to memory )
+
 |c000 @FRAME BRK
 |d000 @ERROR BRK 
+
 |FFFA .RESET .FRAME .ERROR

uxn.c

@@ -31,7 +31,7 @@ Uint16 pop16(St8 *s) { return pop8(s) + (pop8(s) << 8); }
 Uint16 peek16(St8 *s, Uint8 a) { return peek8(s, a * 2) + (peek8(s, a * 2 + 1) << 8); }
 /* I/O */
 void op_brk(Uxn *u) { setflag(&u->status,FLAG_HALT, 1); }
-void op_li1(Uxn *u) { u->literal += 1; }
+void op_lit(Uxn *u) { u->literal += 1; }
 void op_lix(Uxn *u) { u->literal += u->ram.dat[u->ram.ptr++]; }
 void op_nop(Uxn *u) { printf("0x%02x ", pop8(&u->wst)); }
 void op_ior(Uxn *u) { Device *dev = &u->dev[mempeek8(&u->ram, u->devr)]; if(dev) push8(&u->wst, dev->read(dev, pop8(&u->wst))); }
@@ -61,6 +61,7 @@ void op_neq(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst,
 void op_gth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b > (Sint8)a : b > a); }
 void op_lth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b < (Sint8)a : b < a); }
 /* --- */
+void op_lit16(Uxn *u) { u->literal += 2; }
 void op_nop16(Uxn *u) { printf("%04x\n", pop16(&u->wst)); }
 void op_ior16(Uxn *u) { Uint8 a = pop8(&u->wst); Device *dev = &u->dev[mempeek8(&u->ram, u->devr)]; if(dev) push16(&u->wst, (dev->read(dev, a) << 8) + dev->read(dev, a + 1)); }
 void op_iow16(Uxn *u) { Uint8 a = pop8(&u->wst); Uint8 b = pop8(&u->wst); Device *dev = &u->dev[mempeek8(&u->ram, u->devw)]; if(dev) { dev->write(dev, b); dev->write(dev, a); } }
@@ -86,12 +87,12 @@ void op_gth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u-
 void op_lth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint16)b < (Sint16)a : b < a); }
 
 void (*ops[])(Uxn *u) = {
-	op_brk, op_nop, op_li1, op_lix, op_ior, op_iow, op_ldr, op_str, 
+	op_brk, op_nop, op_lit, op_lix, op_ior, op_iow, op_ldr, op_str, 
 	op_jmp, op_jsr, op_nop, op_rts, op_nop, op_nop, op_nop, op_nop, 
 	op_pop, op_dup, op_swp, op_ovr, op_rot, op_and, op_ora, op_rol,
 	op_add, op_sub, op_mul, op_div, op_equ, op_neq, op_gth, op_lth,
 	/* 16-bit */
-	op_brk, op_nop16, op_li1, op_lix, op_ior16, op_iow16, op_ldr16, op_str16, 
+	op_brk, op_nop16, op_lit16, op_lix, op_ior16, op_iow16, op_ldr16, op_str16, 
 	op_jmp, op_jsr, op_nop, op_rts, op_nop, op_nop, op_nop, op_nop, 
 	op_pop16, op_dup16, op_swp16, op_ovr16, op_rot16, op_and16, op_ora16, op_rol16,
 	op_add16, op_sub16, op_mul16, op_div16, op_equ16, op_neq16, op_gth16, op_lth16