Started implementing errors

README.md

@@ -17,20 +17,20 @@ cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
 ```
 < conditionals >
 
-+03 +02    ADD 
-+05        EQU
+0302	ADD 
+05		EQU
 
-.there     JMQ
+.there	JMQ
 
 :here
-  < when not equal >
-  +ee
-  BRK
+	< when not equal >
+	ee
+	BRK
 
 :there
-  < when is equal >
-  +ff
-  BRK
+	< when is equal >
+	ff
+	BRK
 ```
 
 ## Mission
@@ -44,10 +44,6 @@ cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
 - Print word to stdout
 - Draw pixel to screen
 - Detect mouse click
-- 16 bits addressing
-- jumping to subroutine should be relative
-- Implement addressing
-- Implement 16 bits operations
 - Jumps should be relative
 - Catch overflow/underflow
 - Audo-detect literals length.
@@ -55,6 +51,13 @@ cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
 - Build PPU
 - Interrupts
 
+### 16 Bit Missions
+
+- 16 bits addressing
+- jumping to subroutine should be relative
+- Implement addressing
+- Implement 16 bits operations
+
 ## Refs
 
 https://code.9front.org/hg/plan9front/file/a7f9946e238f/sys/src/games/nes/cpu.c

examples/cond.usm

@@ -1,16 +1,16 @@
 < conditionals >
 
-+03 +02    ADD 
-+05        EQU
+0302	ADD 
+05		EQU
 
-.there     JMQ
+.there	JMQ
 
 :here
-  < when not equal >
-  +ee
-  BRK
+	< when not equal >
+	ee
+	BRK
 
 :there
-  < when is equal >
-  +ff
-  BRK
+	< when is equal >
+	ff
+	BRK

examples/core.usm

@@ -1,4 +1,4 @@
 < core >
 
-+12 +34 ADD
+01 ADD
 

examples/jump.usm

@@ -1,7 +1,7 @@
-< conditionals >
+< jump >
 
-.end       JMP
+.end JMP BRK
 
-:end
-  +ff
-  BRK
+:end 
+	ff
+	BRK

examples/rstack.usm

@@ -1,18 +0,0 @@
-< comment >
-
-.deep JSR [4 6 7 8 9 ] BRK
-
-:deep
-	[2 1 2 ] 
-	.deeper JSR 
-	RTS
-
-:deeper
-	[3 3 4 5 ] 
-	.deeperyet JSR
-	RTS
-
-:deeperyet
-	[2 aa bb ]
-	RTS
-	

examples/subroutines.usm

@@ -2,17 +2,17 @@
 
 :begin
   .addall JSR ADD ADD
-  +06 EQU .isequal JSR
+  06 EQU .isequal JSR
   BRK
 
 :add1
-  +01 RTS
+  01 RTS
 
 :add2
-  +02 RTS
+  02 RTS
 
 :add3
-  +03 RTS
+  03 RTS
 
 :addall
   .add1 JSR
@@ -21,5 +21,5 @@
   RTS
 
 :isequal
-  .addall JSR +ff
+  .addall JSR ff
   RTS

uxn.c

@@ -19,15 +19,15 @@ WITH REGARD TO THIS SOFTWARE.
 #define STACK_DEPTH 256
 
 typedef unsigned char Uint8;
+typedef unsigned short Uint16;
 
 typedef struct {
-	Uint8 literal;
-	Uint8 status, counter;
-	Uint8 memory[STACK_DEPTH];
+	Uint8 literal, status;
 	Uint8 mptr, sptr, rsptr;
+	Uint8 memory[STACK_DEPTH];
 	Uint8 stack[STACK_DEPTH];
 	Uint8 rstack[STACK_DEPTH];
-	Uint8 address[STACK_DEPTH];
+	Uint16 counter;
 } Computer;
 
 Computer cpu;
@@ -92,7 +92,7 @@ rspop(void)
 
 void op_brk() { setflag(FLAG_HALT, 1); }
 void op_rts() {	cpu.mptr = rspop(); }
-void op_lit() { cpu.literal += 1; }
+void op_lit() { cpu.literal += cpu.memory[cpu.mptr++]; }
 void op_drp() { spop(); }
 void op_dup() { spush(cpu.stack[cpu.sptr - 1]); }
 void op_swp() { Uint8 b = spop(), a = spop(); spush(b); spush(a); }
@@ -100,8 +100,8 @@ void op_ovr() { spush(cpu.stack[cpu.sptr - 2]); }
 void op_rot() { Uint8 c = spop(),b = spop(),a = spop(); spush(b); spush(c); spush(a); }
 void op_jmp() { cpu.mptr = spop(); }
 void op_jsr() { rspush(cpu.mptr); cpu.mptr = spop(); }
-void op_jmq() { if(getflag(FLAG_ZERO)){ op_jmp(); } setflag(FLAG_ZERO,0); }
-void op_jsq() { if(getflag(FLAG_ZERO)){ op_jsr(); } setflag(FLAG_ZERO,0); }
+void op_jmq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ cpu.mptr = a; } setflag(FLAG_ZERO,0); }
+void op_jsq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ rspush(cpu.mptr); cpu.mptr = a; } setflag(FLAG_ZERO,0); }
 void op_equ() { setflag(FLAG_ZERO, spop() == spop()); }
 void op_neq() { setflag(FLAG_ZERO, spop() != spop()); }
 void op_lth() {	setflag(FLAG_ZERO, spop() < spop()); }
@@ -120,6 +120,13 @@ void (*ops[])(void) = {
 	op_jmp, op_jsr, op_jmq, op_jsq, op_equ, op_neq, op_gth, op_lth, 
 	op_and, op_ora, op_rol, op_ror, op_add, op_sub, op_mul, op_div};
 
+Uint8 opr[][2] = {
+	{0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0},
+	{0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0},
+	{0,0}, {0,0}, {0,0}, {0,0}, {2,1}, {0,0}, {0,0}, {0,0},
+	{0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0}, {0,0},
+};
+
 /* clang-format on */
 
 void
@@ -148,38 +155,40 @@ load(FILE *f)
 	fread(cpu.memory, sizeof(cpu.memory), 1, f);
 }
 
-void
+int
 eval()
 {
 	Uint8 instr = cpu.memory[cpu.mptr++];
 	if(cpu.literal > 0) {
 		spush(instr);
 		cpu.literal--;
-		return;
+		return 1;
 	}
-	if(instr < 24)
+	if(instr < 24) {
+		if(cpu.sptr < opr[instr][0])
+			return error("Stack underflow");
+		/* TODO stack overflow */
 		(*ops[instr])();
+	}
 	if(instr > 0x10)
 		setflag(FLAG_ZERO, 0);
+	cpu.counter++;
+	return 1;
 }
 
 void
 run(void)
 {
-	int i;
-	while((cpu.status & FLAG_HALT) == 0)
-		eval(cpu);
+	while(!(cpu.status & FLAG_HALT) && eval(cpu))
+		;
 	/* debug */
-	printf("ended @ %d  |  ", cpu.counter);
+	printf("ended @ %d steps | ", cpu.counter);
 	printf("hf: %x zf: %x cf: %x tf: %x\n",
-		getflag(FLAG_HALT),
-		getflag(FLAG_ZERO),
-		getflag(FLAG_CARRY),
-		getflag(FLAG_TRAPS));
-	printf("\n\n");
-	for(i = 0; i < 4; i++)
-		printf("%d-", (cpu.status & (1 << i)) != 0);
-	printf("\n\n");
+		getflag(FLAG_HALT) != 0,
+		getflag(FLAG_ZERO) != 0,
+		getflag(FLAG_CARRY) != 0,
+		getflag(FLAG_TRAPS) != 0);
+	printf("\n");
 }
 
 int

uxnasm.c

@@ -29,33 +29,14 @@ typedef struct {
 int labelslen;
 Label labels[256];
 
+/* clang-format off */
+
 char opcodes[][4] = {
-	"BRK",
-	"RTS",
-	"LIT",
-	"POP",
-	"DUP",
-	"SWP",
-	"OVR",
-	"ROT",
-	/* */
-	"JMP",
-	"JSR",
-	"JMQ",
-	"JSQ",
-	"EQU",
-	"NEQ",
-	"LTH",
-	"GTH",
-	"---",
-	"---",
-	"---",
-	"---",
-	"ADD",
-	"SUB",
-	"MUL",
-	"DIV"
-	/* */};
+	"BRK", "RTS", "LIT", "POP", "DUP", "SWP", "OVR", "ROT",
+	"JMP", "JSR", "JMQ", "JSQ", "EQU", "NEQ", "LTH", "GTH",
+	"AND", "ORA", "ROL", "ROR", "ADD", "SUB", "MUL", "DIV"};
+
+/* clang-format on */
 
 Program p;
 
@@ -81,6 +62,15 @@ scpy(char *src, char *dst, int len) /* string copy */
 	return dst;
 }
 
+int
+slen(char *s) /* string length */
+{
+	int i = 0;
+	while(s[i] && s[++i])
+		;
+	return i;
+}
+
 char *
 suca(char *s) /* string to uppercase */
 {
@@ -120,11 +110,41 @@ shex(char *s) /* string to num */
 #pragma mark - Parser
 
 void
-addprg(Uint8 hex)
+pushprg(Uint8 hex)
 {
 	p.data[p.len++] = hex;
 }
 
+void
+pushlabel(Label *l)
+{
+	pushprg(0x02);
+	pushprg(0x01);
+	pushprg(l->addr);
+}
+
+void
+pushliteral(char *w)
+{
+	int len = slen(w) / 2, value = shex(w);
+	pushprg(0x02);
+	pushprg(len);
+	switch(len) {
+	case 1:
+		pushprg(value);
+		break;
+	case 2:
+		pushprg(value >> 8);
+		pushprg(value);
+		break;
+	case 3:
+		pushprg(value >> 16);
+		pushprg(value >> 8);
+		pushprg(value);
+		break;
+	}
+}
+
 void
 addlabel(char *id, Uint8 addr)
 {
@@ -164,10 +184,9 @@ int
 getlength(char *w)
 {
 	if(findop(w) || scmp(w, "BRK")) return 1;
-	if(w[0] == '.') return 2;
+	if(w[0] == '.') return 3;
 	if(w[0] == ':') return 0;
-	if(w[0] == '+') return 2;
-	if(w[0] == '-') return 2;
+	if(sihx(w)) { return slen(w) / 2 + 2; }
 	printf("Unknown length %s\n", w);
 	return 0;
 }
@@ -209,21 +228,14 @@ pass2(FILE *f)
 		if(word[0] == ':') continue;
 		suca(word);
 		if(comment(word, &skip)) continue;
-		/* literals */
-		if(word[0] == '+' || word[0] == '-')
-			addprg(0x02);
-		if(word[0] == '+')
-			addprg(shex(word + 1));
-		else if(word[0] == '-')
-			addprg((Uint8)(-1 * shex(word + 1)));
-		/* opcodes */
-		else if((op = findop(word)) || scmp(word, "BRK"))
-			addprg(op);
-		else if((l = findlabel(word + 1))) {
-			addprg(0x02);
-			addprg(l->addr);
-		} else
-			printf("unknown: %s\n", word);
+		if((op = findop(word)) || scmp(word, "BRK"))
+			pushprg(op);
+		else if((l = findlabel(word + 1)))
+			pushlabel(l);
+		else if(sihx(word))
+			pushliteral(word);
+		else
+			printf("Unknown label: %s\n", word);
 	}
 }