X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;ds=sidebyside;f=bootsplash.asm;h=a6a552a1b79cfa180f0ae6b4273dcfd7e149e130;hb=5731d2abe8e8c4b838f8d1b0eefdc25754f6ad78;hp=26f557acb8f2c36ee4ece51967e7053e59e60f02;hpb=8a2e90cd377e7177f32ffc3ffc30a508e3f5f474;p=bootsplash

diff --git a/bootsplash.asm b/bootsplash.asm
index 26f557a..a6a552a 100644
--- a/bootsplash.asm
+++ b/bootsplash.asm
@@ -37,9 +37,9 @@ start:
 
 	; expects string ptr in ax
 printstr:
-	mov bx, ax
-.loop:	mov al, [bx]
-	inc bx
+	mov si, ax
+.loop:	mov al, [si]
+	inc si
 	test al, al
 	jz .done
 	mov ah, 0eh
@@ -49,7 +49,7 @@ printstr:
 .done:	ret
 
 str_load_fail db "Failed to load second stage!",0
-str_foo db "Loaded 2nd stage boot loader",0
+str_booting db "Booting ...",0
 
 
 	times 510-($-$$) db 0
@@ -57,30 +57,66 @@ str_foo db "Loaded 2nd stage boot loader",0
 
 	; start of the second stage
 stage2_start:
+	call splash
+
+	xor ax, ax
+	mov es, ax
+	mov ds, ax
+
+	mov ax, str_booting
+	call printstr
+
+	cli
+.hang:	hlt
+	jmp .hang
+
+	; splash screen effect
+splash:
 	mov ax, 13h
 	int 10h
 
 	mov ax, 0a000h
 	mov es, ax
 	xor di, di
-	mov cx, 32000
-	mov ax, 0505h
-	rep stosw
+
+	mov ax, pic
+	shr ax, 4
+	mov ds, ax
+	xor si, si
+
+	mov cx, 64000
+	call decode_rle
 
 	call waitkey
 
 	mov ax, 3
 	int 10h
+	ret
 
-	xor ax, ax
-	mov es, ax
-
-	mov ax, str_foo
-	call printstr
-
-.hang:	cli
-	hlt
-	jmp .hang
+	; decode RLE from ds:si to es:di, cx: number of decoded bytes (0 means 65536)
+	; - high bit set for the repetition count, followed by a value byte to
+	;   be repeated N times
+	; - high bit not set for raw data that should be copied directly
+decode_rle:
+	mov al, [si]
+	inc si
+	mov bl, 1	; default to "copy once" for raw values
+	test al, 0x80	; test the high bit to see if it's a count or a raw value
+	jz .copy
+	; it's a count, clear the high bit, and read the next byte for the value
+	and al, 0x7f
+	mov bl, al
+	mov al, [si]
+	inc si
+.copy:	mov [es:di], al
+	inc di
+	dec cx		; decrement decoded bytes counter
+	jz .end		; as soon as it reaches 0, bail
+	dec bl
+	jnz .copy
+	jmp decode_rle
+.end:	ret
+	
 
 waitkey:
 	in al, 64h
@@ -89,6 +125,10 @@ waitkey:
 	in al, 60h
 	ret
 
+	; data
+	align 16
+pic:	incbin "nuclear.rle"
+
 stage2_end:
 
 ; vi:set ft=nasm: