ucl_project_y3/memory/risc8.asm

%define COM_UARTF 	0x03
%define COM_UARTW 	0x05
%define COM_UARTR 	0x04
%define COM_LED 	0x06
%define COM_DIP 	0x08
%define COM_UARTIN 	0x09
%define NULL 		0x000000
%define LF          0x0a
%define CR          0x0d
%define LFCR        0x0a0d
%define COM_UART_TRANS 	0b0000_0001
%define COM_UART_RECV 	0b0000_0010
%define COM_UART_ECHO 	0b0000_0100
%define COM_UART_RR 	0b0000_1000 ; Read Ready

section .data 2x3x8192
intro_text DB 0x1B63,0x1B5B324A,0x1B5B34303B33313B316D,"GLaDOS v0.0",0x1B5B303B33323B34306D," starting..",LFCR,0
eq1_text DB LFCR,"1) 0x1194 * 0x2710 = 0x",0
eq2_text DB LFCR,"2) 3*2=",0
eq3_text DB LFCR,"3) 3*2=",0
initial_vt100 DB 0x1B,'c',0x1B,"[2J",0x1B,"[40;32m",0
error_text DB LFCR,"Invalid operation: ",0
error0 DB "Buffer is full",0
mul16buf DBE 8
generalbuf DBE 1
termHiFlag 	DB  0x0000
termBuff 	DB  10,0
			DBE 10
mallocPointer DB 0
section .text 1x2x4096
setup
	CPY0 65432@1
	CPY1 65432@0
	CALL printU16

	; Run init
	INTRE interrupt
	;CALL read_char
	;CALL print_char
;.echo
;	JUMP .echo
;	CALL read_char
;	CALL print_char

	CPY1 intro_text@0	
	CPY2 intro_text@1	
	CALL print_msg
	;CALL read_char
	;CPY1 COM_UART_ECHO
	;COM r1,COM_UARTF
	CPY1 eq1_text@0	
	CPY2 eq1_text@1	
	CALL print_msg
	CPY0 0x11  ; 4500
	CPY1 0x94
	CPY2 0x27  ; 10000
	CPY3 0x10
	CALL mulU16
	CALL printhex
	MOVE r0,r1
	CALL printhex
	MOVE r0,r2
	CALL printhex
	MOVE r0,r3
	CALL printhex
	CALL println
loop
	CPY0 0
	PUSH r0
	CPY0 '>'
	CALL print_char
	CPY0 0x20  ; space
	CALL print_char
;.loop
;	CALL read_char
;	CALL print_char
;	;BEQ r2,0x0a,.start
;	BEQ r0,0x0d,.error
;	JUMP .loop
;.error	
;	CPY1 error_text@0	
;	CPY2 error_text@1	
;	CALL print_msg
;	JUMP .start

.read
	CALL read_char
	BGT r0,57,.readc0 
	BGT r0,48,.readadd
.readc0
	BEQ r0,0x0d,.done
	;BEQ r0,0x20,.echo
	BEQ r0,0x08,.backspace
	BEQ r0,0x7F,.backspace
	BEQ r0,0x2A,.readadd  ; *
	BEQ r0,0x2B,.readadd  ; +
	BEQ r0,0x2D,.readadd  ; -
	BEQ r0,0x2F,.readadd  ; /
	JUMP .read
.backspace
;	POP r1
;	BEQ r1,0,.backspaceCheck
;	CPY0 0x1B
;	CALL print_char
;	CPY0 'c'
;	CALL print_char
;	JUMP .read
;.backspaceCheck
;	PUSH r1
	JUMP .read
.readadd
	LWLO r3,termHiFlag
	BZ r3,.readadd0
	JUMP .readstore
.readadd0
	CPY3 1
	SWHI r0
	SWLO r3,termHiFlag
	JUMP .echo
.readstore
	CPY2 0
	LWHI r3,termHiFlag
	SWLO r2,termHiFlag
	MOVE r2,r0
	CPY0 termBuff@0
	CPY1 termBuff@1
	CALL arrayPush
	; Check if buffer overflow
	BZ r0,.readstore0
	MOVE r0,r2
	JUMP .echo
.readstore0
	MOVE r0,r2
	BZ r1,.error0
.echo
	CALL print_char
	JUMP .read
.done
	; if odd number of chars, push r0, 0 to array
	LWLO r3,termHiFlag
	BZ r3,.doneC
	;LWHI r2,termHiFlag
	;CPY3 0
	;CPY0 termBuff@0
	;CPY1 termBuff@1
	;CALL arrayPush
.doneC
	CPY1 termBuff@0
	CPY2 termBuff@1
	CALL Process
	CPY0 termBuff@0
	CPY1 termBuff@1
	CALL arrayClear
	JUMP loop
.done0
	POP r0
	BEQ r0,0,.done1
	CALL print_char
	JUMP .done0
.done1
	CALL println
	JUMP loop

.error0
	CALL println
	CPY1 error0@0	
	CPY2 error0@1	
	CALL print_msg
	CALL println
	JUMP loop

	MOVE r1,r0
	SUBI r1,48
	CALL print_char

	CALL read_char
	MOVE r2,r0
	CALL print_char
	
	CALL read_char
	MOVE r3,r0
	SUBI r3,48
	CALL print_char
	
	BEQ r2,'+',.add
	BEQ r2,'-',.sub
	JUMP .invalid
.add
	ADD r1,r3
	JUMP .result
.sub
	SUB r1,r3	
	JUMP .result
.invalid
	CPY1 error_text@0	
	CPY2 error_text@1	
	CALL print_msg
	JUMP .done
.result
	PUSH r1
	CPY0 '='
	CALL print_char
	POP r0
	ADDI r0,48
	CALL print_char

Process
	; Input array *{r2 r1}
	;CPY1 termBuff@0
	;CPY2 termBuff@1
.readnext
	INC r1
	ADDC r2
	CI1 r2
	CI0 r1
	SWLO r0,NULL
.isdigit
	;BGT r0,57,.issymbol 
	;BGT r0,48,.digit
.issymbol
	;JUMP .error 
.digit
	;CI1 r2
	;CI0 r1
	;SWHI r0
.error	
	CPY1 error_text@0	
	CPY2 error_text@1	
	CALL print_msg
	CPY1 termBuff@0
	CPY2 termBuff@1
	INC r1
	ADDC r2
	CALL print_msg
.end
	CALL println
	RET


printbin
; print r0 as binary
	PUSH r2
	PUSH r1
	CPY2 0b1000_0000	
	MOVE r1,r0
.start	
	AND r0,r2
	BZ r0,.print0
.print1
	CPY0 '1'
	CALL print_char
	JUMP .end
.print0
	CPY0 '0'
	CALL print_char
.end
	SRL r2,1
	BZ r2,.done
	MOVE r0,r1
	JUMP .start
.done
	POP r1
	POP r2
	RET	

printhex
; print r0 as hex
	PUSH r0
	PUSH r1
	MOVE r1,r0
	SRL r0,4
	BGT r0,9,.p0
	ADDI r0,48
	JUMP .p1
.p0
	ADDI r0,55
.p1	
	CALL print_char
	MOVE r0,r1
	POP r1
	ANDI r0,0b0000_1111
	BGT r0,9,.p2
	ADDI r0,48
	JUMP .p3
.p2
	ADDI r0,55
.p3	
	CALL print_char
	POP r0
	RET
	

;.done
	;; Equation 1
	;CPY1 eq1_text@0	
	;CPY2 eq1_text@1	
	;CALL print_msg
	;CPY0 3
	;ADDI r0,2
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char
	;
	;; Equation 2
	;CPY1 eq2_text@0	
	;CPY2 eq2_text@1	
	;CALL print_msg
	;CPY0 6
	;SUBI r0,2
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char

	;; Equation 3
	;CPY1 eq3_text@0	
	;CPY2 eq3_text@1	
	;CALL print_msg
	;CPY0 3
	;CPY1 2
	;MUL r0,r1
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char
	;
	;CPY1 eq3x_text@0	
	;CPY2 eq3x_text@1	
	;CALL print_msg
	;GETAH r0
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char

	;; Equation 4
	;CPY1 eq4_text@0	
	;CPY2 eq4_text@1	
	;CALL print_msg
	;CPY0 9
	;CPY1 2
	;DIV r0,r1
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char

	;; Equation 5
	;CPY1 eq5_text@0	
	;CPY2 eq5_text@1	
	;CALL print_msg
	;GETAH r0
	;ADDI r0,48 ; Convert to ascii
	;CALL print_char
	
	;CALL println
	;JUMP .start
	;CPY3 0
start
	INC r3
	JUMP start

interrupt
	PUSH r0
	GETIF r0
	POP r0
	RETI

println
	PUSH r0
	CPY0 LF
	CALL print_char
	CPY0 CR
	CALL print_char
	POP r0
	RET



mulU16
	; Multiply 2 unsigned 16-bit int
	; {r0 r1} * {r2 r3}
	;  A  B   *  X  Y
	; Result:
	; r3 = BY0
	; r2 = BY1+BX0+AY0
	; r1 = BX1+AY1+AX0
	; r0 = AX1
	; Carryout must be included to higher bytes
	PUSH r3
	MUL r3,r1 ; BY0
	SWHI r3
	GETAH r3  ; BY1
	SWLO r3,mul16buf
	POP r3   ; Buffer = [BY0 BY1]
	PUSH r2
	MUL r2,r1 ; BX0
	SWHI r2
	GETAH r2  ; BX1
	SWLO r2,mul16buf+1
	POP r2   ; Buffer = [BY0 BY1 BX0 BX1]
	PUSH r3
	MUL r3,r0 ; AY0
	SWHI r3
	GETAH r3  ; AY1
	SWLO r3,mul16buf+2
	POP r3   ; Buffer = [BY0 BY1 BX0 BX1 AY0 AY1]
	PUSH r2
	MUL r2,r0 ; AX0
	SWHI r2
	GETAH r2  ; AX1
	SWLO r2,mul16buf+3
	POP r2   ; Buffer = [BY0 BY1 BX0 BX1 AY0 AY1 AX0 AX1]
			 ;			 {  0  } {  1  } {  2  } {  3  }
	; r3 will be used as spare register as it's equal to BY0
	
	LWLO r2,mul16buf    ; r2=BY1
	LWLO r1,mul16buf+1  ; r1=BX1
	LWLO r0,mul16buf+3  ; r0=AX1
	LWHI r3,mul16buf+1  ;  t=BX0
	ADD r2,r3
	ADDC r1
	ADDC r0
	LWHI r3,mul16buf+2  ;  t=AY0
	ADD r2,r3
	ADDC r1
	ADDC r0
	LWLO r3,mul16buf+2  ;  t=AY1
	ADD r1,r3
	ADDC r0
	LWHI r3,mul16buf+3  ;  t=AX0
	ADD r1,r3
	ADDC r0
	LWHI r3,mul16buf    ; r3=BY0
	RET	

bin2digit
	; Converts U16 to digit
	; Adopted from http://www.avr-asm-tutorial.net/avr_en/calc/CONVERT.html#bin2bcd
	; Digit {r0 r1}, Place in 10^n {r2 r3}
	PUSH r0
	CPY0 0
	SWLO r0,generalbuf  ; Using general buf to store number
	POP r0
.a
	CI2 r0
	BGT r2,0,.c  ; MSB is smaller than digit
	CI2 r2
	BGT r0,0,.b ; MSB is grater than digit
	CI2 r1
	BGT r3,0,.c ; LSB is smaller than digit
.b
	PUSH r0
	LWLO r0,generalbuf
	INC r0
	SWLO r0,generalbuf 
	POP r0
	SUB r0,r2
	SUB r1,r3
	SUBC r0
	JUMP .a
.c
	LWLO r2,generalbuf
	RET	

printU16
; print unsigned 16bit int as base-10 digit
; arguments: digit {r0, r1}
	PUSH r0
	PUSH r1
	PUSH r2
	PUSH r3

	CPY2 10000@1
	CPY3 10000@0
	CALL bin2digit
	MOVE r3,r0
	MOVE r0,r2
	ADDI r0,48 ; Convert to ascii digit
	CALL print_char
	MOVE r0,r3
	
	CPY2 1000@1
	CPY3 1000@0
	CALL bin2digit
	MOVE r3,r0
	MOVE r0,r2
	ADDI r0,48 ; Convert to ascii digit
	CALL print_char
	MOVE r0,r3

	CPY2 0
	CPY3 100
	CALL bin2digit
	MOVE r0,r2
	ADDI r0,48 ; Convert to ascii digit
	CALL print_char

	MOVE r0,r1
	CALL printU8

	POP r3
	POP r2
	POP r1
	POP r0
	RET

printU8
	; Assuing number is 128
	; a = 128%10 = 8
	; a = 128%100 - a // 10 = 2
	; a = 128%1000 - a // 100 = 1
	; in case of 8bit number quicker is to do 2 if statements for 100s
	; input argument is in r0
	PUSH r0
	PUSH r1
	PUSH r2
	PUSH r3
	CPY2 10
	
	MOVE r1,r0
	DIV r1,r2
	GETAH r1
	PUSH r1  ; Stored last digit
	BGE r0,10,.ge10
	JUMP .p3
.ge10
	CPY2 100
	MOVE r3,r0
	DIV r3,r2
	GETAH r3
	SUB r3,r1
	CPY2 10
	DIV r3,r2
	PUSH r3  ; Stored middle digit

	BGE r0,100,.ge100
	JUMP .p2
.ge100
	CPY2 200
	CI2 r2
	BGE r0,0,.s2
	CPY2 100
	CI2 r2
	BGE r0,0,.s1
	JUMP .p2
.s1 CPY0 '1'
	JUMP .p0
.s2 CPY0 '2'
.p0 CALL print_char
.p2 
	POP r0
	ADDI r0,48
	CALL print_char
.p3 
	POP r0
	ADDI r0,48
	CALL print_char
	POP r3
	POP r2
	POP r1
	POP r0
	RET

arrayClear	
	; Clear array at *{r1 r0}
	PUSH r2
	CI1 r1
	CI0 r0
	LWHI r2,NULL
	SWHI r2
	CPY2 0
	CI1 r1
	CI0 r0
	SWLO r2,NULL
	POP r2
	RET

arrayPush
	; Push to array *{r1 r0} value {r3 r2}
	; If full, changes r1 r0 to 0x0000
	PUSH r2
	PUSH r3

	CI1 r1
	CI0 r0
	LWLO r2,NULL

	CI1 r1
	CI0 r0
	LWHI r3,NULL ; Stores cap
	; r2=size, r3=cap

	CI2 r3
	BGE r2,0xFF,.full
	INC r2
	SWHI r3
	CI1 r1
	CI0 r0
	SWLO r2,NULL
	
	ADD r0,r2
	ADDC r1

	POP r3
	SWHI r3
	POP r2
	CI1 r1
	CI0 r0
	SWLO r2,NULL
	RET
.full
	POP r3
	POP r2
	CPY0 0
	CPY1 0
	RET

arrayPop
	; Pop from array *{r1 r0} value {r3 r2}
	; If empty, changes all regs to 0x00
	CI1 r1
	CI0 r0
	LWLO r2,NULL
	BEQ r2,0,.empty
	DEC r2
	CI1 r1
	CI0 r0
	SWLO r2,NULL
	INC r2
	ADD r0,r2
	ADDC r1
	CI1 r1
	CI0 r0
	LWHI r3,NULL
	CI1 r1
	CI0 r0
	LWLO r2,NULL
	RET
.empty
	CPY3 0
	CPY2 0
	CPY1 0
	CPY0 0
	RET

read_char  ; read char to r0
	COM r0,COM_UARTR
	ANDI r0,0b0000_1000
	BZ r0,read_char
	COM r0,COM_UARTIN
	RET

malloc ; returns memory free memory locaion
	; r0 = size to allocate
	; {r2, r1} memory pointer
	LWHI r2,mallocPointer	
	LWLO r1,mallocPointer
	PUSH r2
	PUSH r1
	ADD r1,r0
	ADDC r2
	SWHI r2
	SWLO r1,mallocPointer	
	POP r1
	POP r2
	RET

print_msg  ; print value in mem pinter {r2 r1}
	PUSH r0
.loop
	CI1 r2
	CI0 r1
	LWHI r0,NULL
	BZ r0,.end
	CALL print_char
	CI1 r2
	CI0 r1
	LWLO r0,NULL	
	BZ r0,.end
	CALL print_char
	INC r1
	ADDC r2
	JUMP .loop
.end
	POP r0
	RET

print_char  ; print value in r0
	PUSH r0
.loop
	COM r0,COM_UARTR
	ANDI r0,0b0000_0010
	XORI r0,0b0000_0010 ; invert
	BZ r0,.loop
	POP r0
	COM r0,COM_UARTW
	RET