Factored out string operations to procedures

Strings32.nasm

@@ -84,41 +84,52 @@ IntToString:
 ; IN: esi = base of string buffer
 ; IN: edx = justification width
 ; IN: ecx = string length
+; IN: al  = padding char
 ; ASSUMES: that the justification width > string length
 ; ASSUMES: that the size of the string buffer > justification width 
 RightJustifyString:
-	push	esi
-	push	edx
-	push	ecx
-	push	eax
+	pushad
 	pushfd
+	
+	lea	edi, [esi + edx-1]
+	lea	esi, [esi + ecx-1]
 
-	lea	esi, [esi + ecx]	; should include null terminator
-	lea	edi, [esi + edx]	
+	sub	edx, ecx
 
-	std
-	sub	edx, ecx		; edx should be difference
+	std			; Move string from the end
+	rep movsb			;  |
+	
+	mov	ecx, edx
+	rep stosb			; Pad with AL
+	
+	popfd
+	popad
+	ret
 
-.copy_loop:
-	lodsb			; al = char
-	stosb
-	sub	ecx, 1
-	jnz 	.copy_loop
 
-; 	mov	al, byte ' '
-; .pad_loop:	
-; 	movsb
-; 	sub	edx, 1
-; 	jnz	.pad_loop
 
-	pushfd
-	pop	eax
-	pop	ecx
-	pop	edx
-	pop	esi
-	ret
 
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Copies ecx bytes
+; IN: esi = source
+; IN: edi = destination
+; IN: ecx = number of bytes to copy
+CopyData:
+	pushad
+	
+	mov	edx, ecx
+	and	edx, 11b
+	shr 	ecx, 2
+	; ecx = quotient, edx = remainder
+
+	rep movsd
+	mov	ecx, edx
+	rep movsb
+
+	popad
+	ret
+
 
 
 

build.sh

@@ -9,5 +9,5 @@ if [ "$1" != "run" ]; then
 fi
 
 if [ "$1" != "make" ]; then
-	qemu-system-x86_64.exe -drive index=0,format=raw,file=SingOS.img 
+	qemu-system-x86_64 -drive index=0,format=raw,file=SingOS.img 
 fi

go32bit.nasm

@@ -250,12 +250,16 @@ ProtectedModeBaby:
 	mov	fs, ax
 	mov	gs, ax
 
+
 	; Setup stack
-	mov	esp, 0x8000000
+	mov	esp, (100 << 20) - 1	; 100M Addressable
 	mov	ebp, esp
 
+	; Space for dynamic variables
+	sub	esp, 200*4		; 200 32-bit integers
 
 
+	push	ebp
 
 DrawStuff:
 	xor	ecx, ecx
@@ -307,7 +311,7 @@ DrawStuff:
 	cmp	edx, VIDEO_Y_RES-2
 	jne	.DrawLoop
 
-
+	pop	ebp
 
 
 	cld
@@ -391,48 +395,53 @@ DrawStuff:
 	jmp	.print_loop
 .break_print_loop:
 	
-	lea	edi, [VIDEO + ScreenCoord(1, 24)]
-	mov	ecx, 34
-	mov	eax, 0
-	rep	stosd
+	lea	esi, [VarLabels]
+	lea	edi, [ConversionBuffer]
+	mov	ecx, VarLabelsLength
+	call	CopyData
 
 	lea	esi, [ConversionBuffer]
+	lea	edi, [VIDEO + ScreenCoord(0, 24)]
+	mov	ah, 0x0f
+	call	PrintString
+
+
+	; lea	esi, [ConversionBuffer]
 	mov	eax, dword [Px]
 	sar	eax, 4
 	call	IntToString
 	
-	push	ecx
-
-	lea	esi, [ConversionBuffer]
-	mov	edx, 6
+	; lea	esi, [ConversionBuffer]
+	;	ecx set by IntToString
+	mov	edx, 7
+	mov	al, ' '
 	call	RightJustifyString
 
-
-	lea	edi, [VIDEO + ScreenCoord(1, 24)]
-	mov	ah, 0x0f
+	;	esi still ConversionBuffer
+	mov	ecx, edx
+	lea	edi, [VIDEO + ScreenCoord(StrXStart, 24)]
+	mov	ah, 0x70
 	call	PrintString
 
-	lea	esi, [ConversionBuffer]
-	pop	eax
+
+	; lea	esi, [ConversionBuffer]
+	mov	eax, dword [Py]
+	sar	eax, 4
 	call	IntToString
 	
-	lea	esi, [ConversionBuffer]
-	lea	edi, [VIDEO + ScreenCoord(40, 24)]
-	mov	ah, 0x0f
-	call	PrintString
-
+	; lea	esi, [ConversionBuffer]
+	;	ecx set by IntToString
+	mov	edx, 7
+	mov	al, ' '
+	call	RightJustifyString
 
+	;	esi still ConversionBuffer
+	mov	ecx, edx
+	lea	edi, [VIDEO + ScreenCoord(StrYStart, 24)]
+	mov	ah, 0x70
+	call	PrintString
 
-	; add	edi, 12*2
-	
-	; mov	eax, dword [Py]
-	; sar	eax, 4
-	; call	IntToString
 
-	; add	edi, 12*2
-	; mov	eax, [Zoom]
-	; sar	eax, 9
-	; call	IntToString
 
 	add	[ColorOffset], dword 1
 
@@ -462,7 +471,17 @@ Reboot:
 ;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Strings
 ;;;;;;;;;;;;;;;;;;;;;;;;
+VarLabels:		db "X:"
+StrXStart equ $-VarLabels
+		db "        "
+		db "Y:"
+StrYStart equ $-VarLabels
+		db "        "
+VarLabelsLength	equ $-VarLabels
 ProtectedWelcomeStr:	db " Placeholder for SingOS - 32 bit edition! ", 0
+ProtectedWelcomeStrLength equ $-ProtectedWelcomeStr
+TestStr:		db "hello, world"
+TestStrLength	equ $-TestStr
 ThereWasSomethingStr:	db " KEY = '"
 Key:		db " ' ", 0
 Px:		dd 0