1 files changed, 13 insertions, 5 deletions

diff --git a/sys/dev/vt/hw/ofwfb/ofwfb.c b/sys/dev/vt/hw/ofwfb/ofwfb.c
index ab9c99d3fe3d..5d5f421ca9fb 100644
--- a/sys/dev/vt/hw/ofwfb/ofwfb.c
+++ b/sys/dev/vt/hw/ofwfb/ofwfb.c
@@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$");
 #ifdef __sparc64__
 #include <machine/bus_private.h>
 #endif
+#include <machine/cpu.h>
 
 #include <dev/ofw/openfirm.h>
 #include <dev/ofw/ofw_bus.h>
@@ -138,6 +139,7 @@ ofwfb_bitblt_bitmap(struct vt_device *vd, const struct vt_window *vw,
 		if (pmap_bootstrapped) {
 			sc->fb_flags &= ~FB_FLAG_NOWRITE;
 			ofwfb_initialize(vd);
+			vd->vd_driver->vd_blank(vd, TC_BLACK);
 		} else {
 			return;
 		}
@@ -490,11 +492,6 @@ ofwfb_init(struct vt_device *vd)
 		OF_decode_addr(node, fb_phys, &sc->sc_memt, &sc->fb.fb_vbase,
 		    NULL);
 		sc->fb.fb_pbase = sc->fb.fb_vbase & ~DMAP_BASE_ADDRESS;
-		#ifdef __powerpc64__
-		/* Real mode under a hypervisor probably doesn't cover FB */
-		if (!(mfmsr() & (PSL_HV | PSL_DR)))
-			sc->fb.fb_flags |= FB_FLAG_NOWRITE;
-		#endif
 	#else
 		/* No ability to interpret assigned-addresses otherwise */
 		return (CN_DEAD);
@@ -502,6 +499,17 @@ ofwfb_init(struct vt_device *vd)
         }
 
 
+	#if defined(__powerpc__)
+	/*
+	 * If we are running on PowerPC in real mode (supported only on AIM
+	 * CPUs), the frame buffer may be inaccessible (real mode does not
+	 * necessarily cover all RAM) and may also be mapped with the wrong
+	 * cache properties (all real mode accesses are assumed cacheable).
+	 * Just don't write to it for the time being.
+	 */
+	if (!(cpu_features & PPC_FEATURE_BOOKE) && !(mfmsr() & PSL_DR))
+		sc->fb.fb_flags |= FB_FLAG_NOWRITE;
+	#endif
 	ofwfb_initialize(vd);
 	vt_fb_init(vd);