printf(): Allow padding (spaces or zeroes) for %b

src/console.asm

@@ -84,6 +84,7 @@ puts:
 ;	r10*	Keeps track of current index of printfBuff
 ;	r11*	Keeps track of total characters (return value)
 ;	r12	Padding for numbers (0=nopadding, >0=padding w/ spaces, NOT >0=padding w/ zeroes)
+;	r13	Padding: zeroes (=1) or spaces (=0)
 printf:
 	%macro load_arg 1
 	cmp	rdx, 4
@@ -100,9 +101,13 @@ printf:
 	push	rax
 	push	rdx
 	push	rdi
+	push	r9
+	push	r10
 	%endmacro
 
 	%macro pop_regs 0
+	pop	r10
+	pop	r9
 	pop	rdi
 	pop	rdx
 	pop	rax
@@ -112,6 +117,8 @@ printf:
 	; entry:
 	push	rbp
 	mov	rbp, rsp
+	push	r12
+	push	r13
 
 	cmp	byte [rdi], EOS
 	je	.emptyStr
@@ -148,14 +155,16 @@ printf:
 		je	.wrapup
 		cmp	byte [rdi + 1], '%'
 		je	.rep_pct
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-		cmp	byte [rdi + 1], '1' ;zero padding later!
+		xor	r13, r13
+		mov	r12, 1
+		cmp	byte [rdi + 1], '0'
 		jb	.noPadding
+		cmove	r13, r12
 		cmp	byte [rdi + 1], '9'
 		jg	.noPadding
-		
-		inc	rdi ;point to after '%'
-		xor	rcx, rcx ;length of padding number (set to 0 first)
+		xor	r12, r12
+		xor	rcx, rcx
+		inc	rdi
 		.findPaddingNumLen:
 			cmp	byte [rdi], EOS
 			je	.wrapup
@@ -167,11 +176,10 @@ printf:
 			inc	rdi
 			jmp	.findPaddingNumLen
 		.getPadding:
-		dec	rdi ;dont break .noPadding below (for cmp rdi+1)
+		dec	rdi
 		push	rdi
 		push	rax
 		xor	rax, rax
-		xor	r12, r12 ;total len
 		mov	r9, 1
 		.getPaddingLoop:
 			xor	rax, rax
@@ -186,10 +194,10 @@ printf:
 			mov	r9, rax
 			loop	.getPaddingLoop
 		pop	rax
-		pop	rdi ;r12 should now store padding length
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-		; OK so at this point, padding (spaces, zeroes not yet supported) length is calculated correctly and string is replaced correctly.
-		; Now what remains is to actually add the spaces (and zeroes, eventually)
+		pop	rdi
+		test	r13, r13
+		jz	.noPadding
+		not	r12
 		.noPadding:
 		cmp	byte [rdi + 1], 'c'
 		je	.rep_c
@@ -270,6 +278,20 @@ printf:
 			load_arg rsi
 			push_regs
 		mov	rdi, rsi
+		;
+		mov	rdx, 0
+		test	r12, r12
+		jz	.callB2S
+		test	r12, r12
+		js	.notB2S
+		jmp	.callB2S
+		.notB2S:
+		not	r12
+		mov	rdx, 1
+		jmp	.callB2S
+		;
+		.callB2S:
+		mov	rsi, r12
 		call	bin2str
 		mov	rsi, rax
 			pop_regs
@@ -342,6 +364,7 @@ printf:
 	xor	rax, rax
 
 	.quit:
+	pop	r13
 	pop	r12
 	leave
 	ret