From d734e48a7188cffe926b241a356021e48023fe76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakob=20Kj=C3=A6r-Kammersgaard?= <jakkj16@student.sdu.dk>
Date: Wed, 21 Nov 2018 23:39:00 +0100
Subject: [PATCH] Factored out string operations to procedures

---
 IntToString.o  | Bin 992 -> 0 bytes
 Strings32.nasm |  59 ++++++++++++++++++++++---------------
 build.sh       |   2 +-
 go32bit.nasm   |  77 ++++++++++++++++++++++++++++++-------------------
 4 files changed, 84 insertions(+), 54 deletions(-)
 delete mode 100644 IntToString.o

diff --git a/IntToString.o b/IntToString.o
deleted file mode 100644
index ff4c2b058c2f6e591501ed7805008e3bfee23a88..0000000000000000000000000000000000000000
GIT binary patch
literal 0
HcmV?d00001

literal 992
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zbue2V06F?lIS|DHW%B}Qm>Q6f022d)Ayf`Tfy@8_aUcdt!9f6!^8m<W1!9mHAoD<W
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zxtC`W<4MgE%?AuRy#IGzXuVYW*z#Vn82>gl{%yiQ4b86^JHq~VI5S#)E`Jpf9T$H%
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z@jtS1)RYDae<lV=paNaEB1Q&PAlnv+ZwF+%Ao0V1>{KLv4v<}q#BYMLK@28_HXsR#
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zj?C7}%P)z~OHEHK$t+7nkx0ob%S=g)&&kg(KoKu4Pb|P9nw?n?50YZYEly|1NiWHW
b2QiXL)6!Cl7;;kcpzZ|ug%Ox0#h^3*J`I&;

diff --git a/Strings32.nasm b/Strings32.nasm
index b61132a..3fefd94 100644
--- a/Strings32.nasm
+++ b/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
+
 
 
 
diff --git a/build.sh b/build.sh
index 90c5716..884d0f4 100644
--- a/build.sh
+++ b/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
diff --git a/go32bit.nasm b/go32bit.nasm
index bbf13a4..c3b6a78 100644
--- a/go32bit.nasm
+++ b/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