Progress on branching

README.md

@@ -34,6 +34,17 @@ $01 < pointer8 >
 :label ADD RTS
 ```
 
+## Mission
+
+- Loop
+- Conditional example
+- Pointers/Literals
+- Print word to stdout
+- Draw pixel to screen
+- Detect mouse click
+- 16 bits addressing
+- jumping to subroutine should be relative
+
 ## TODOs
 
 - Implement addressing
@@ -44,6 +55,7 @@ $01 < pointer8 >
 - Audo-detect literals length.
 - SDL Layer Emulator
 - Build PPU
+- Interrupts
 
 ## Refs
 

build.sh

@@ -13,12 +13,6 @@ rm -f ./boot.rom
 cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werror=implicit-int -Werror=incompatible-pointer-types -Werror=int-conversion -Wvla -g -Og -fsanitize=address -fsanitize=undefined uxnasm.c -o uxnasm
 cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werror=implicit-int -Werror=incompatible-pointer-types -Werror=int-conversion -Wvla -g -Og -fsanitize=address -fsanitize=undefined uxn.c -o uxn
 
-# build(fast)
-# cc uxn.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -o uxn
-
-# Size
-# echo "Size: $(du -sk ./uxn)"
-
 # run
-./uxnasm example.usm boot.rom
+./uxnasm examples/cond.usm boot.rom
 ./uxn boot.rom

examples/cond.usm

@@ -0,0 +1,16 @@
+< conditionals >
+
++03 +02    ADD 
++05        EQU
+
+.there     JMQ
+
+:here
+  < when not equal >
+  +ee
+  BRK
+
+:there
+  < when is equal >
+  +ff
+  BRK

examples/core.usm

@@ -0,0 +1,3 @@
+< core >
+
++12 -34

examples/jump.usm

@@ -0,0 +1,7 @@
+< conditionals >
+
+.end       JMP
+
+:end
+  +ff
+  BRK

uxn.c

@@ -91,8 +91,8 @@ rspop(void)
 /* clang-format off */
 
 void op_brk() { setflag(FLAG_HALT, 1); }
-void op_lit() { cpu.literal += cpu.memory[cpu.mptr++]; }
-void op_nop() { }
+void op_rts() {	cpu.mptr = rspop(); }
+void op_lit() { cpu.literal += 1;}
 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_jeq() { if(getflag(FLAG_ZERO)) cpu.mptr = spop(); }
-void op_rts() {	cpu.mptr = rspop(); }
+void op_jmq() { if(getflag(FLAG_ZERO)) op_jmp(); }
+void op_jsq() { if(getflag(FLAG_ZERO)) op_jsr(); }
 void op_equ() { setflag(FLAG_ZERO, spop() == spop()); }
 void op_neq() { setflag(FLAG_ZERO, spop() != spop()); }
 void op_lth() {	setflag(FLAG_ZERO, spop() < spop()); }
@@ -116,8 +116,8 @@ void op_mul() { spush(spop() * spop()); }
 void op_div() { spush(spop() / spop()); }
 
 void (*ops[])(void) = {
-	op_brk, op_lit, op_nop, op_drp, op_dup, op_swp, op_ovr, op_rot, 
-	op_jmp, op_jsr, op_jeq, op_rts, op_equ, op_neq, op_gth, op_lth, 
+	op_brk, op_rts, op_lit, op_drp, op_dup, op_swp, op_ovr, op_rot, 
+	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};
 
 /* clang-format on */

uxnasm.c

@@ -31,8 +31,8 @@ Label labels[256];
 
 char opcodes[][4] = {
 	"BRK",
+	"RTS",
 	"LIT",
-	"---",
 	"POP",
 	"DUP",
 	"SWP",
@@ -41,8 +41,8 @@ char opcodes[][4] = {
 	/* */
 	"JMP",
 	"JSR",
-	"JEQ",
-	"RTS",
+	"JMQ",
+	"JSQ",
 	"EQU",
 	"NEQ",
 	"LTH",
@@ -164,11 +164,10 @@ int
 getlength(char *w)
 {
 	if(findop(w) || scmp(w, "BRK")) return 1;
-	if(w[0] == '.') return 3;
+	if(w[0] == '.') return 2;
 	if(w[0] == ':') return 0;
-	if(w[0] == '[') return 2;
-	if(sihx(w)) return 1;
-	if(w[0] == ']') return 0;
+	if(w[0] == '+') return 2;
+	if(w[0] == '-') return 2;
 	printf("Unknown length %s\n", w);
 	return 0;
 }
@@ -205,28 +204,23 @@ pass2(FILE *f)
 	int skip = 0;
 	char word[64];
 	while(fscanf(f, "%s", word) == 1) {
-		Uint8 op;
+		Uint8 op = 0;
 		Label *l;
 		if(word[0] == ':') continue;
 		suca(word);
 		if(comment(word, &skip)) continue;
-		if(word[0] == ']') continue;
-		if(word[0] == '+') {
-			addprg(0x01);
-			addprg(1);
+		/* literals */
+		if(word[0] == '+' || word[0] == '-')
+			addprg(0x02);
+		if(word[0] == '+')
 			addprg(shex(word + 1));
-		} else if(word[0] == '[') {
-			addprg(0x01);
-			addprg(shex(word + 1));
-		} else if((op = findop(word)))
+		else if(word[0] == '-')
+			addprg((Uint8)(-1 * shex(word + 1)));
+		/* opcodes */
+		else if((op = findop(word)) || scmp(word, "BRK"))
 			addprg(op);
-		else if(sihx(word))
-			addprg(shex(word));
-		else if(scmp(word, "BRK"))
-			addprg(0x00);
 		else if((l = findlabel(word + 1))) {
-			addprg(0x01);
-			addprg(1);
+			addprg(0x02);
 			addprg(l->addr);
 		} else
 			printf("unknown: %s\n", word);