Quack 2

linux/d_copy.s

@@ -0,0 +1,147 @@
+/
+// d_copy.s
+// x86 assembly-language screen copying code.
+//
+
+#include "qasm.h"
+
+	.data
+
+LCopyWidth:		.long	0
+LBlockSrcStep:	.long	0
+LBlockDestStep:	.long	0
+LSrcDelta:		.long	0
+LDestDelta:		.long	0
+
+#define bufptr	4+16
+
+// copies 16 rows per plane at a pop; idea is that 16*512 = 8k, and since
+// no Mode X mode is wider than 360, all the data should fit in the cache for
+// the passes for the next 3 planes
+
+	.text
+
+.globl C(VGA_UpdatePlanarScreen)
+C(VGA_UpdatePlanarScreen):
+	pushl	%ebp				// preserve caller's stack frame
+	pushl	%edi
+	pushl	%esi				// preserve register variables
+	pushl	%ebx
+
+	movl	C(VGA_bufferrowbytes),%eax
+	shll	$1,%eax
+	movl	%eax,LBlockSrcStep
+	movl	C(VGA_rowbytes),%eax
+	shll	$1,%eax
+	movl	%eax,LBlockDestStep
+
+	movl	$0x3C4,%edx
+	movb	$2,%al
+	outb	%al,%dx		// point the SC to the Map Mask
+	incl	%edx
+
+	movl	bufptr(%esp),%esi
+	movl	C(VGA_pagebase),%edi
+	movl	C(VGA_height),%ebp
+	shrl	$1,%ebp
+
+	movl	C(VGA_width),%ecx
+	movl	C(VGA_bufferrowbytes),%eax
+	subl	%ecx,%eax
+	movl	%eax,LSrcDelta
+	movl	C(VGA_rowbytes),%eax
+	shll	$2,%eax
+	subl	%ecx,%eax
+	movl	%eax,LDestDelta
+	shrl	$4,%ecx
+	movl	%ecx,LCopyWidth
+
+LRowLoop:
+	movb	$1,%al
+
+LPlaneLoop:
+	outb	%al,%dx
+	movb	$2,%ah
+
+	pushl	%esi
+	pushl	%edi
+LRowSetLoop:
+	movl	LCopyWidth,%ecx
+LColumnLoop:
+	movb	12(%esi),%bh
+	movb	8(%esi),%bl
+	shll	$16,%ebx
+	movb	4(%esi),%bh
+	movb	(%esi),%bl
+	movl	%ebx,(%edi)
+	addl	$16,%esi
+	addl	$4,%edi
+	decl	%ecx
+	jnz		LColumnLoop
+
+	addl	LDestDelta,%edi
+	addl	LSrcDelta,%esi
+	decb	%ah
+	jnz		LRowSetLoop
+
+	popl	%edi
+	popl	%esi
+	incl	%esi
+
+	shlb	$1,%al
+	cmpb	$16,%al
+	jnz		LPlaneLoop
+
+	subl	$4,%esi
+	addl	LBlockSrcStep,%esi
+	addl	LBlockDestStep,%edi
+	decl	%ebp
+	jnz		LRowLoop
+
+	popl	%ebx				// restore register variables
+	popl	%esi
+	popl	%edi
+	popl	%ebp				// restore the caller's stack frame
+
+	ret
+
+
+#define srcptr			4+16
+#define destptr			8+16
+#define width			12+16
+#define height			16+16
+#define srcrowbytes		20+16
+#define destrowbytes	24+16
+
+.globl C(VGA_UpdateLinearScreen)
+C(VGA_UpdateLinearScreen):
+	pushl	%ebp				// preserve caller's stack frame
+	pushl	%edi
+	pushl	%esi				// preserve register variables
+	pushl	%ebx
+
+	cld
+	movl	srcptr(%esp),%esi
+	movl	destptr(%esp),%edi
+	movl	width(%esp),%ebx
+	movl	srcrowbytes(%esp),%eax
+	subl	%ebx,%eax
+	movl	destrowbytes(%esp),%edx
+	subl	%ebx,%edx
+	shrl	$2,%ebx
+	movl	height(%esp),%ebp
+LLRowLoop:
+	movl	%ebx,%ecx
+	rep/movsl	(%esi),(%edi)
+	addl	%eax,%esi
+	addl	%edx,%edi
+	decl	%ebp
+	jnz		LLRowLoop
+
+	popl	%ebx				// restore register variables
+	popl	%esi
+	popl	%edi
+	popl	%ebp				// restore the caller's stack frame
+
+	ret
+