shithub: riscv

Info  •  Files  •  Log  •  Branches

bcm64: map framebuffer write-through to allow unaligned access

--- a/sys/src/9/bcm64/mem.h

+++ b/sys/src/9/bcm64/mem.h

@@ -63,7 +63,7 @@

 #define MACHADDR(n)	(KTZERO-((n)+1)*MACHSIZE)

 #define	KTZERO		(KZERO+0x80000)		/* kernel text start */

-#define FRAMEBUFFER	0xFFFFFFFFC0000000ULL

+#define FRAMEBUFFER	(0xFFFFFFFFC0000000ULL | PTEWT)

 #define VIRTIO		0xFFFFFFFFE0000000ULL	/* i/o registers */

 #define	ARMLOCAL	(VIRTIO+IOSIZE)

 #define	VGPIO		0			/* virtual gpio for pi3 ACT LED */

@@ -125,7 +125,7 @@

 #define PTEWT		PTEMA(MA_MEM_WT)

 #define	PTEUNCACHED	PTEMA(MA_MEM_UC)

-#define	PTEDEVICE	PTEMA(MA_DEV_nGnRnE)

+#define	PTEDEVICE	PTEMA(MA_DEV_nGnRE)

 /*

  * Physical machine information from here on.

--- a/sys/src/9/bcm64/mmu.c

+++ b/sys/src/9/bcm64/mmu.c

@@ -124,18 +124,19 @@

 uintptr

 mmukmap(uintptr va, uintptr pa, usize size)

 {

-	uintptr a, pe, off;

+	uintptr a, pe, off, attr;

 	if(va == 0)

 		return 0;

-	assert((va % PGLSZ(1)) == 0);

+	attr = va & PTEMA(7);

+	va &= -PGLSZ(1);

 	off = pa % PGLSZ(1);

 	a = va + off;

 	pe = (pa + size + (PGLSZ(1)-1)) & -PGLSZ(1);

 	while(pa < pe){

 		((uintptr*)L1)[PTL1X(va, 1)] = pa | PTEVALID | PTEBLOCK | PTEWRITE | PTEAF

-			| PTEKERNEL | PTESH(SHARE_OUTER) | PTEDEVICE;

+			| PTEKERNEL | PTESH(SHARE_OUTER) | attr;

 		pa += PGLSZ(1);

 		va += PGLSZ(1);

 	}