ref: 06eb848b99587ef882c121a5a65d2082e3b88aeb
dir: qk1/u/d_copy.s
// // d_copy.s // x86 assembly-language screen copying code. // #include "asm_i386.h" #include "quakeasm.h" #include "asm_draw.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