diff --git a/sys/arch/x86/x86/bus_space.c b/sys/arch/x86/x86/bus_space.c
index f06321b..c9d4ca3 100644
--- a/sys/arch/x86/x86/bus_space.c
+++ b/sys/arch/x86/x86/bus_space.c
@@ -153,6 +153,8 @@ x86_bus_space_mallocok(void)
 	ioport_malloc_safe = 1;
 }
 
+#include <ddb/ddb.h>
+
 int
 bus_space_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 		int flags, bus_space_handle_t *bshp)
@@ -161,6 +163,12 @@ bus_space_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 	bus_space_tag_t it;
 	int error;
 
+	if ((bpa <= 0xc0000 && 0xc0000 - bpa < size )) {
+		printf("%s: mapping vga rom\n", __func__);
+		db_stack_trace_print((db_expr_t)(intptr_t)
+		    __builtin_frame_address(0), true, 65536, "", printf);
+	}
+
 	if ((t->bst_exists & BUS_SPACE_OVERRIDE_MAP) == 0)
 		;	/* skip override */
 	else for (it = t; it != NULL; it = it->bst_super) {
@@ -169,11 +177,19 @@ bus_space_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size,
 		return (*it->bst_ov->ov_space_map)(it->bst_ctx, t, bpa, size,
 		    flags, bshp);
 	}
+	if ((bpa <= 0xc0000 && 0xc0000 - bpa < size ))
+	  aprint_normal("%s: %s:%d %08x %08x %08x %08x %08x\n",
+			__func__, __FILE__,__LINE__,
+			 (unsigned int) t, (unsigned int) bpa,
+			size, flags, (unsigned int) &bsr);
 
 	error = bus_space_reserve(t, bpa, size, flags, &bsr);
 	if (error != 0)
 		return error;
 
+	if ((bpa <= 0xc0000 && 0xc0000 - bpa < size ))
+	aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
+
 	error = bus_space_reservation_map(t, &bsr, flags, bshp);
 	if (error != 0)
 		bus_space_release(t, &bsr);
diff --git a/sys/external/bsd/drm2/dist/drm/drm_stub.c b/sys/external/bsd/drm2/dist/drm/drm_stub.c
index 550a653..767751e 100644
--- a/sys/external/bsd/drm2/dist/drm/drm_stub.c
+++ b/sys/external/bsd/drm2/dist/drm/drm_stub.c
@@ -42,7 +42,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_core.h>
 
-unsigned int drm_debug = 0;	/* 1 to enable debug output */
+unsigned int drm_debug = 4;	/* 1 to enable debug output */
 EXPORT_SYMBOL(drm_debug);
 
 unsigned int drm_rnodes = 0;	/* 1 to enable experimental render nodes API */
diff --git a/sys/external/bsd/drm2/dist/drm/i915/intel_bios.c b/sys/external/bsd/drm2/dist/drm/i915/intel_bios.c
index b7b7ffd..e9e5ab8 100644
--- a/sys/external/bsd/drm2/dist/drm/i915/intel_bios.c
+++ b/sys/external/bsd/drm2/dist/drm/i915/intel_bios.c
@@ -936,11 +936,13 @@ intel_parse_bios(struct drm_device *dev)
 			dev_priv->opregion.vbt = NULL;
 	}
 
+	aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
 	if (bdb == NULL) {
 		struct vbt_header *vbt = NULL;
 		size_t size;
 		int i;
 
+		aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
 		bios = pci_map_rom(pdev, &size);
 		if (!bios)
 			return -1;
diff --git a/sys/external/bsd/drm2/include/linux/pci.h b/sys/external/bsd/drm2/include/linux/pci.h
index b0425cd..ad8c007 100644
--- a/sys/external/bsd/drm2/include/linux/pci.h
+++ b/sys/external/bsd/drm2/include/linux/pci.h
@@ -475,6 +475,8 @@ pci_unmap_rom(struct pci_dev *pdev, void __pci_rom_iomem *vaddr __unused)
 static int
 pci_map_rom_md(struct pci_dev *pdev)
 {
+aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
+
 #if defined(__i386__) || defined(__x86_64__) || defined(__ia64__)
 	const bus_addr_t rom_base = 0xc0000;
 	const bus_size_t rom_size = 0x20000;
@@ -486,11 +488,25 @@ pci_map_rom_md(struct pci_dev *pdev)
 	if (PCI_SUBCLASS(pdev->pd_pa.pa_class) != PCI_SUBCLASS_DISPLAY_VGA)
 		return ENXIO;
 	/* XXX Check whether this is the primary VGA card?  */
+
+	aprint_normal("%s: %s:%d %08lx bsh(%08lx) size(%08lx)\n",
+		      __func__, __FILE__,__LINE__,
+		      (long unsigned int) pdev->pd_pa.pa_memt,
+		      (long unsigned int) rom_bsh,
+		      (long unsigned int) rom_size
+		      );
 	error = bus_space_map(pdev->pd_pa.pa_memt, rom_base, rom_size,
 	    (BUS_SPACE_MAP_LINEAR | BUS_SPACE_MAP_PREFETCHABLE), &rom_bsh);
 	if (error)
 		return ENXIO;
 
+	aprint_normal("%s: %s:%d %08lx bsh(%08lx) size(%08lx)\n",
+		      __func__, __FILE__,__LINE__,
+		      (long unsigned int) pdev->pd_pa.pa_memt,
+		      (long unsigned int) rom_bsh,
+		      (long unsigned int) rom_size
+		      );
+
 	pdev->pd_rom_bst = pdev->pd_pa.pa_memt;
 	pdev->pd_rom_bsh = rom_bsh;
 	pdev->pd_rom_size = rom_size;
@@ -507,6 +523,7 @@ pci_map_rom(struct pci_dev *pdev, size_t *sizep)
 	bus_space_handle_t bsh;
 	bus_size_t size;
 
+	aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
 	KASSERT(!ISSET(pdev->pd_kludges, NBPCI_KLUDGE_MAP_ROM));
 
 	if (pci_mapreg_map(&pdev->pd_pa, PCI_MAPREG_ROM, PCI_MAPREG_TYPE_ROM,
@@ -517,6 +534,8 @@ pci_map_rom(struct pci_dev *pdev, size_t *sizep)
 		return NULL;
 	pdev->pd_kludges |= NBPCI_KLUDGE_MAP_ROM;
 
+	aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
+
 	/* XXX This type is obviously wrong in general...  */
 	if (pci_find_rom(&pdev->pd_pa, pdev->pd_rom_bst, pdev->pd_rom_bsh,
 		pdev->pd_rom_size, PCI_ROM_CODE_TYPE_X86, &bsh, &size)) {
@@ -524,9 +543,15 @@ pci_map_rom(struct pci_dev *pdev, size_t *sizep)
 		return NULL;
 	}
 
+	aprint_normal("%s: %s:%d\n",__func__, __FILE__,__LINE__);
 	KASSERT(size <= SIZE_T_MAX);
 	*sizep = size;
 	pdev->pd_rom_vaddr = bus_space_vaddr(pdev->pd_rom_bst, bsh);
+	aprint_normal("%s: %s:%d size(%08x) rom_size(%08x)\n",
+		      __func__, __FILE__,__LINE__,
+		      size,
+		      pdev->pd_rom_size
+		      );
 	return pdev->pd_rom_vaddr;
 }