Hello world with strlen

README.md

@@ -27,6 +27,10 @@ cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
 - `|0010`, move to position in the program
 - `"hello`, push literal bytes for word "hello"
 
+### Operator modes
+
+- `,1234 ,0001 ADD^`, 16-bits operators have the short flag `^`.
+
 ```
 ( hello world )
 

examples/core.usm

@@ -6,14 +6,19 @@
 
 |0100 @RESET
 
-"hello
+@word1 "hello_word ( len: 0x0b )
 
 @loop
-	,dev1w STR
+	,dev1w STR ( write to stdout )
-	,incr JSU ( call incr )
+	,incr JSU ( increment itr )
-	,05 NEQ ,loop ROT JSC
+	,word1 ,strlen JSU ( get strlen )
+	NEQ ,loop ROT JSC ( loop != strlen )
 
-BRK ( RESET )
+BRK
+
+@strlen
+	,0001 ADD^ PEK
+	RTS
 
 @incr
 	,iterator LDR

examples/hello.usm

@@ -0,0 +1,32 @@
+( hello world )
+
+;iterator
+:dev1r FFF0
+:dev1w FFF1
+
+|0100 @RESET
+
+@word1 "hello_word ( len: 0x0b )
+
+@loop
+	,dev1w STR ( write to stdout )
+	,incr JSU ( increment itr )
+	,word1 ,strlen JSU ( get strlen )
+	NEQ ,loop ROT JSC ( loop != strlen )
+
+BRK
+
+@strlen
+	,0001 ADD^ PEK
+	RTS
+
+@incr
+	,iterator LDR
+	,01 ADD
+	,iterator STR 
+	,iterator LDR
+	RTS
+
+|c000 @FRAME BRK 
+|d000 @ERROR BRK 
+|FFFA .RESET .FRAME .ERROR

uxn.c

@@ -12,7 +12,7 @@ WITH REGARD TO THIS SOFTWARE.
 */
 
 #define FLAG_HALT 0x01
-#define FLAG_ZERO 0x02
+#define FLAG_SHORT 0x02
 #define FLAG_CARRY 0x04
 #define FLAG_TRAPS 0x08
 
@@ -96,6 +96,7 @@ Uint8 rampeek8(Uint16 s) { return cpu.ram.dat[s] & 0xff; }
 Uint8 mempeek8(Uint16 s) { return cpu.rom.dat[s]; }
 Uint16 mempeek16(Uint16 s) { return (cpu.rom.dat[s] << 8) + (cpu.rom.dat[s+1] & 0xff); }
 void wspush8(Uint8 b) { cpu.wst.dat[cpu.wst.ptr++] = b; }
+void wspush16(Uint16 s) { wspush8(s >> 8); wspush8(s & 0xff); }
 Uint8 wspop8(void) { return cpu.wst.dat[--cpu.wst.ptr]; }
 Uint16 wspop16(void) { return wspop8() + (wspop8() << 8); }
 Uint8 wspeek8(void) { return cpu.wst.dat[cpu.wst.ptr - 1]; }
@@ -122,18 +123,25 @@ void op_and() {	wspush8(wspop8() & wspop8()); }
 void op_ora() { wspush8(wspop8() | wspop8()); }
 void op_rol() { wspush8(wspop8() << 1); }
 void op_ror() { wspush8(wspop8() >> 1); }
-void op_add() { wspush8(wspop8() + wspop8()); }
+void op_add() { 
+	if(getflag(FLAG_SHORT))
+		wspush16(wspop16() + wspop16()); 
+	else
+		wspush8(wspop8() + wspop8()); 
+}
 void op_sub() { wspush8(wspop8() - wspop8()); }
 void op_mul() { wspush8(wspop8() * wspop8()); }
 void op_div() { wspush8(wspop8() / wspop8()); }
 void op_ldr() { wspush8(cpu.ram.dat[wspop16()]); }
 void op_str() { cpu.ram.dat[wspop16()] = wspop8(); }
+void op_pek() { wspush8(cpu.rom.dat[wspop16()]); }
+void op_pok() { printf("TODO:\n");}
 
-void (*ops[])(void) = {
+void (*ops[])() = {
 	op_brk, op_rts, op_lit, op_drp, op_dup, op_swp, op_ovr, op_rot, 
 	op_jmu, op_jsu, op_jmc, op_jsc, op_equ, op_neq, op_gth, op_lth, 
 	op_and, op_ora, op_rol, op_ror, op_add, op_sub, op_mul, op_div,
-	op_ldr, op_str, op_brk, op_brk, op_brk, op_brk, op_brk, op_brk
+	op_ldr, op_str, op_pek, op_pok, op_brk, op_brk, op_brk, op_brk
 };
 
 Uint8 opr[][2] = {
@@ -162,9 +170,9 @@ reset(void)
 }
 
 int
-error(char *name)
+error(char *name, int id)
 {
-	printf("Error: %s, at 0x%04x\n", name, cpu.counter);
+	printf("Error: %s[%04x], at 0x%04x\n", name, id, cpu.counter);
 	return 0;
 }
 
@@ -177,31 +185,48 @@ device1(Uint8 *read, Uint8 *write)
 	return 0;
 }
 
+void
+opc(Uint8 src, Uint8 *op, Uint8 *mode)
+{
+	*op = src;
+	*op &= ~(1 << 5);
+	*op &= ~(1 << 6);
+	*op &= ~(1 << 7);
+	*mode = src;
+	*mode &= ~(1 << 0);
+	*mode &= ~(1 << 1);
+	*mode &= ~(1 << 2);
+	*mode &= ~(1 << 3);
+}
+
 int
 eval(void)
 {
 	Uint8 instr = cpu.rom.dat[cpu.rom.ptr++];
+	Uint8 op, opmode;
+	/* when literal */
 	if(cpu.literal > 0) {
 		wspush8(instr);
 		cpu.literal--;
 		return 1;
 	}
-	if(instr < 32) {
+	/* when opcode */
-		if(cpu.wst.ptr < opr[instr][0])
+	opc(instr, &op, &opmode);
-			return error("Stack underflow");
+	setflag(FLAG_SHORT, (instr >> 5) & 1);
-		/* TODO stack overflow */
+	if((instr >> 6) & 1)
-		(*ops[instr])();
+		printf("Unused flag: %02x\n", instr);
-	}
+	if((instr >> 7) & 1)
-	if(instr > 0x10)
+		printf("Unused flag: %02x\n", instr);
-		setflag(FLAG_ZERO, 0);
+	/* TODO: setflag(FLAG_B, (instr >> 6) & 1); */
-	if(cpu.counter == 128) {
+	/* TODO: setflag(FLAG_C, (instr >> 7) & 1); */
-		return error("Reached bounds");
+	if(cpu.wst.ptr < opr[op][0])
-	}
+		return error("Stack underflow", op);
+	(*ops[op])();
 	cpu.counter++;
 	return 1;
 }
 
-void
+int
 start(FILE *f)
 {
 	reset();
@@ -216,6 +241,8 @@ start(FILE *f)
 		/* experimental */
 		if(cpu.ram.dat[0xfff1])
 			device1(&cpu.ram.dat[0xfff0], &cpu.ram.dat[0xfff1]);
+		if(cpu.counter > 256)
+			return error("Reached bounds", cpu.counter);
 	}
 	/*eval frame */
 	printf("\nPhase: frame\n");
@@ -227,10 +254,11 @@ start(FILE *f)
 	printf("ended @ %d steps | ", cpu.counter);
 	printf("hf: %x zf: %x cf: %x tf: %x\n",
 		getflag(FLAG_HALT) != 0,
-		getflag(FLAG_ZERO) != 0,
+		getflag(FLAG_SHORT) != 0,
 		getflag(FLAG_CARRY) != 0,
 		getflag(FLAG_TRAPS) != 0);
 	printf("\n");
+	return 1;
 }
 
 int
@@ -238,10 +266,11 @@ main(int argc, char *argv[])
 {
 	FILE *f;
 	if(argc < 2)
-		return error("No input.");
+		return error("No input.", 0);
 	if(!(f = fopen(argv[1], "rb")))
-		return error("Missing input.");
+		return error("Missing input.", 0);
-	start(f);
+	if(!start(f))
+		return error("Program error", 0);
 	/* print result */
 	echos(&cpu.wst, 0x40, "stack");
 	echom(&cpu.ram, 0x40, "ram");

uxnasm.c

@@ -29,11 +29,11 @@ Label labels[256];
 
 /* clang-format off */
 
-char opcodes[][4] = {
+char ops[][4] = {
 	"BRK", "RTS", "LIT", "POP", "DUP", "SWP", "OVR", "ROT",
 	"JMU", "JSU", "JMC", "JSC", "EQU", "NEQ", "GTH", "LTH",
 	"AND", "ORA", "ROL", "ROR", "ADD", "SUB", "MUL", "DIV",
-	"LDR", "STR", "---", "---", "---", "---", "---", "---"
+	"LDR", "STR", "PEK", "POK", "---", "---", "---", "---"
 };
 
 /* clang-format on */
@@ -162,6 +162,27 @@ findlabel(char *s)
 	return NULL;
 }
 
+Uint8
+findop(char *s)
+{
+	int i;
+	for(i = 0; i < 32; ++i) {
+		int m = 0;
+		if(ops[i][0] != s[0]) continue;
+		if(ops[i][1] != s[1]) continue;
+		if(ops[i][2] != s[2]) continue;
+		while(s[3 + m]) {
+			char c = s[3 + m];
+			if(c == '^') i |= (1 << 5); /* mode: 16 bits */
+			if(c == '&') i |= (1 << 6); /* mode: unused */
+			if(c == '~') i |= (1 << 7); /* mode: unused */
+			m++;
+		}
+		return i;
+	}
+	return 0;
+}
+
 #pragma mark - Parser
 
 int
@@ -171,16 +192,6 @@ error(char *name, char *id)
 	return 0;
 }
 
-Uint8
-findop(char *s)
-{
-	int i;
-	for(i = 0; i < 32; ++i)
-		if(scmp(opcodes[i], s))
-			return i;
-	return 0;
-}
-
 int
 makelabel(char *id, Uint16 addr)
 {
@@ -210,7 +221,6 @@ pass1(FILE *f)
 	char w[64];
 	while(fscanf(f, "%s", w) == 1) {
 		if(iscomment(w, &skip)) continue;
-		suca(w);
 		if(w[0] == '@' && !makelabel(w + 1, addr))
 			return error("Pass1 failed", w);
 		if(w[0] == ';' && !makelabel(w + 1, vars++))
@@ -253,7 +263,6 @@ pass2(FILE *f)
 		Label *l;
 		if(w[0] == '@') continue;
 		if(w[0] == ';') continue;
-		suca(w);
 		if(iscomment(w, &skip)) continue;
 		if(w[0] == '|')
 			p.ptr = shex(w + 1);
@@ -261,10 +270,10 @@ pass2(FILE *f)
 			fscanf(f, "%s", w);
 		else if(w[0] == '"')
 			pushword(w + 1);
-		else if((op = findop(w)) || scmp(w, "BRK"))
-			pushbyte(op, 0);
 		else if((l = findlabel(w + 1)))
 			pushshort(l->addr, w[0] == ',');
+		else if((op = findop(w)) || scmp(w, "BRK"))
+			pushbyte(op, 0);
 		else if(sihx(w + 1) && slen(w + 1) == 2)
 			pushbyte(shex(w + 1), w[0] == ',');
 		else if(sihx(w + 1) && slen(w + 1) == 4)