Added access of DATA section for LDI and SVI.

README.md

@@ -34,14 +34,14 @@ The meat of the project:
 * `common/common.h`: details of instructions
 * `common/common.asm`: assembler code for the instructions
 * `common/macros.h`: macros used to define the interpreted byte-code
-* `common/page6.src`: sample source file using the macros
+* `common/appl.src`: sample source file using the macros
 
 Auxiliary:
 
 * `emulator/*`: 6502 emulator (borrowed Mike Chambers’ Fake6502 CPU emulator v1.1 ©2011)
 * `xa-pre-process/*`: my utility `xapp` to convert 32-bit fixed decimal quantities so that `xa` can use them
 
-Right now, for testing purposes, the code builds everything into one file `system.obj` and runs the code in the last block loaded, in this case, the code corresponding to `page6.src`. Eventually will support decoupling of system and application files. Application files will be inherently relocatable.
+Right now, for testing purposes, the code builds everything into one file `system.obj` and runs the code in the last block loaded, in this case, the code corresponding to `appl.src`. Eventually will support decoupling of system and application files. Application files will be inherently relocatable.
 
 To build and run:
 

common/Makefile

@@ -1,17 +1,17 @@
 XAPP=../xa-pre-process/xapp
 
-system.obj: common.obj page6.obj
+system.obj: common.obj appl.obj
-	cat common.obj page6.obj > system.obj
+	cat common.obj appl.obj > system.obj
 
 common.obj: rom.h common.h common.asm
 	xa -C -M common.asm -l common.lbl -o common.obj
 
-page6.obj: rom.h macros.h globals.h page6.src
+appl.obj: rom.h macros.h globals.h appl.src
-	cpp -P page6.src | $(XAPP) > page6.asm
+	cpp -P appl.src | $(XAPP) > appl.asm
-	xa -C -M page6.asm -l page6.lbl -o page6.obj
+	xa -C -M appl.asm -l appl.lbl -o appl.obj
 
 globals.h: common.obj
 	grep -E '^(FN_XR|FN_0X|PLS_1|MNS_1|ADDR)' common.lbl | sed -e 's/, 0, 0x0000//' -e 's/, / = /' -e 's/ 0x/ \x24/' > globals.h
 
 clean:
-	rm -f globals.h page6.asm common.obj page6.obj common.lbl page6.lbl system.obj
+	rm -f globals.h appl.asm common.obj appl.obj common.lbl appl.lbl system.obj

common/appl.src

@@ -2,27 +2,31 @@
 #include "macros.h"
 #include "globals.h"
 
-	* = $1000		; any address outside of page zero is okay
+	* = $300		; any address outside of page zero is okay because all code is relocatable
 
 CODE(DEMO)
+
 START
 	CMN
 	SET(R0, 9.4662)
-	SET(R1, 5)
+	SET(R1, SQRT2)
 	LDI(R7, R1)
 	MUL(R7, R7, R7)
-	SVI(R1, R0)
 	PSH(R0)
 	BRS(FACTORIAL)
 	POP(R4)
-	SET(R5, 1)
+	SET(R5, E)
 	LDI(R6, R5)
+	SET(R1, ZERO)
+	INR(R1)
+	SVI(R1, R6)
+	LDI(R0, R1)
 	ESC
 	BRK
 
 BEGIN(FACTORIAL)
 	POP(R1)
-	SET(R2, 3)
+	SET(R2, 1)
 	MOD(R3, R1, R2)
 	SUB(R1, R1, R3)
 _1	TST(R1)
@@ -36,9 +40,14 @@ END(FACTORIAL)
 
 END(DEMO)
 
-DATA(WORKING)
+DATA(_)
-PI	VALUE(3.14159)
+
-E	VALUE(2.71828)
+	; preset constants
-SQRT2	VALUE(1.41421)
+	DEFINE(PI, 3.14159)
-ZERO	RESERVE(2)
+	DEFINE(E, 2.71828)
-END(WORKING)
+	DEFINE(SQRT2, 1.41421)
+
+	; working space
+	RESERVE(2)
+
+END(_)

common/macros.h

@@ -78,24 +78,23 @@
 #define EXT(f)		.BYTE _EXT_C + (f)
 
 ; header for fixed code or data
-#define FIXED(l)	.BYTE _SM_FXD:.WORD l, _END_##l - l:* = * - 5:l .(
+#define FIXED(l)	.BYTE _SM_FXD : .WORD l, _END_##l - l : * = * - 5 : l .(
 
 ; header for relocatable code: l(abel) => starting offset, length of code
-#define CODE(l)		.BYTE _RLC_CD:.WORD _start - l, _END_##l - l: * = * -5:l .(
+#define CODE(l)		.BYTE _RLC_CD : .WORD _start - l, _END_##l - l : * = * - 5 : l .(
 #define START		&_start
 
 ; header for relocatable data: l(abel) => length of zeroed data, length of preset data
-#define DATA(l)		.BYTE _RLC_DT:.WORD _END_##l - _zero, _zero - l: * = * - 5:l .(
+#define DATA(l)		.BYTE _RLC_DT : .WORD _END_##l - _zero, _zero - l : * = * - 5 : l .( : &_data
-#define ZERO		&_zero
 
-; initialize v(alue)
+; define l(abel), v(alue)
-#define VALUE(v)	.BYTE _SET_V(#v)
+#define DEFINE(l, v)	&l .BYTE _SET_V(#v)
 
-; reserve c(ount)
+; reserve c(ount) & provide an alias for _zero
-#define RESERVE(c)	* = * + c * 4
+#define RESERVE(c)	&ZERO : &_zero : * = * + (c) * 4
 
 ; common begin and end
 #define BEGIN(l)	l .(
-#define END(l)		.):_END_##l
+#define END(l)		.) : _END_##l
 
 #endif /* __MACROS_H */

xa-pre-process/main.c

@@ -27,8 +27,17 @@ int main(int argc, char **argv)
 				const char *s = "", *p, *q;
 				switch (tokens[i].type)
 				{
-					/* Process each _SET_V("<expr>") command */
+					/* Process each _SET_V("<label>") command */
-					case TT_COMMAND:
+					case TT_LABEL:
+						/* Extract the start and ending indices */
+						p = strchr(tokens[i].text, '"') + 1;
+						q = strrchr(tokens[i].text, '"');
+						j = (int)(q - p);
+						/* Output in .BYTE format */
+						printf("0, <(%.*s - _data), >(%.*s - _data), 0", j, p, j, p);
+						break;
+					/* Process each _SET_V("<expression>") command */
+					case TT_EXPRESSION:
 						/* Extract the start and ending indices */
 						p = strchr(tokens[i].text, '"') + 1;
 						q = strrchr(tokens[i].text, '"');

xa-pre-process/xapp.h

@@ -50,7 +50,7 @@
 
 typedef enum
 {
-	TT_COMMAND, TT_DEFAULT, TT_WHITE_SPACE, TT_END_OF_LINE
+	TT_LABEL, TT_EXPRESSION, TT_DEFAULT, TT_WHITE_SPACE, TT_END_OF_LINE
 } TOKEN_TYPE;
 
 typedef struct

xa-pre-process/xapp.re

@@ -72,18 +72,25 @@ int tokenizeInput(const char *cursor, TOKEN *tokens)
 
 		WHITE_SPACE	= BELL | BACKSPACE | HORIZONTAL_TAB | ESCAPE | DELETE | SPACE ;
 
+		SET_V_BGN	= LOW_LINE [Ss][Ee][Tt] LOW_LINE [Vv] WHITE_SPACE* LEFT_PARENTHESIS WHITE_SPACE* QUOTATION_MARK ;
+
+		SET_V_END	= QUOTATION_MARK WHITE_SPACE* RIGHT_PARENTHESIS ;
+
 		VALID		= DIGIT | LETTER | EXCLAMATION_MARK | DOLLAR_SIGN | PERCENT_SIGN | AMPERSAND
 					| LEFT_PARENTHESIS | RIGHT_PARENTHESIS | ASTERISK | PLUS_SIGN | HYPHEN_MINUS
 					| FULL_STOP | SOLIDUS | LESS_THAN_SIGN | EQUALS_SIGN | GREATER_THAN_SIGN
 					| LOW_LINE | VERTICAL_LINE | TILDE | WHITE_SPACE ;
 
-		COMMAND		= LOW_LINE [Ss][Ee][Tt] LOW_LINE [Vv] WHITE_SPACE* LEFT_PARENTHESIS WHITE_SPACE* QUOTATION_MARK VALID+ QUOTATION_MARK WHITE_SPACE* RIGHT_PARENTHESIS ;
+		LABEL		= SET_V_BGN ( LETTER | LOW_LINE ) ( LETTER | LOW_LINE | DIGIT )* SET_V_END ;
+
+		EXPRESSION	= SET_V_BGN VALID+ SET_V_END ;
 
 		DEFAULT		= . ;
 
 		END_OF_LINE	= ( LINE_FEED | VERTICAL_TAB | FORM_FEED | CARRIAGE_RETURN )+ ;
 
-		COMMAND		{ i = copyToken(tokens, i, TT_COMMAND, token, (int)(cursor - token)); continue; }
+		LABEL		{ i = copyToken(tokens, i, TT_LABEL, token, (int)(cursor - token)); continue; }
+		EXPRESSION	{ i = copyToken(tokens, i, TT_EXPRESSION, token, (int)(cursor - token)); continue; }
 		DEFAULT		{ i = copyToken(tokens, i, TT_DEFAULT, token, (int)(cursor - token)); continue; }
 		WHITE_SPACE	{ i = copyToken(tokens, i, TT_WHITE_SPACE, token, (int)(cursor - token)); continue; }
 		END_OF_LINE	{ i = copyToken(tokens, i, TT_END_OF_LINE, token, (int)(cursor - token)); continue; }