Index: kernel/genarch/src/acpi/acpi.c
===================================================================
--- kernel/genarch/src/acpi/acpi.c	(revision adec5b450420e754be2635ab4e7587f68c0a3287)
+++ kernel/genarch/src/acpi/acpi.c	(revision dc9a3bad35af1e44ff24f701c2fc929aba3a5e55)
@@ -39,6 +39,6 @@
 #include <genarch/acpi/madt.h>
 #include <arch/bios/bios.h>
-#include <mm/as.h>
 #include <mm/page.h>
+#include <mm/km.h>
 #include <print.h>
 
@@ -96,11 +96,20 @@
 }
 
-static void map_sdt(struct acpi_sdt_header *sdt)
-{
-	page_table_lock(AS_KERNEL, true);
-	page_mapping_insert(AS_KERNEL, (uintptr_t) sdt, (uintptr_t) sdt,
-	    PAGE_NOT_CACHEABLE | PAGE_WRITE);
-	map_structure((uintptr_t) sdt, sdt->length);
-	page_table_unlock(AS_KERNEL, true);
+static struct acpi_sdt_header *map_sdt(struct acpi_sdt_header *psdt)
+{
+	struct acpi_sdt_header *vhdr;
+	struct acpi_sdt_header *vsdt;
+
+	/* Start with mapping the header only. */
+	vhdr = (struct acpi_sdt_header *) km_map_structure((uintptr_t) psdt,
+	    sizeof(struct acpi_sdt_header), PAGE_READ | PAGE_NOT_CACHEABLE); 
+
+	/* Now we can map the entire structure. */
+	vsdt = (struct acpi_sdt_header *) km_map_structure((uintptr_t) psdt,
+	    vhdr->length, PAGE_WRITE | PAGE_NOT_CACHEABLE);
+	
+	// TODO: do not leak vtmp
+
+	return vsdt; 
 }
 
@@ -118,10 +127,10 @@
 			    (struct acpi_sdt_header *) (sysarg_t) acpi_rsdt->entry[i];
 			
-			map_sdt(hdr);
-			if (CMP_SIGNATURE(hdr->signature, signature_map[j].signature)) {
-				if (!acpi_sdt_check((uint8_t *) hdr))
+			struct acpi_sdt_header *vhdr = map_sdt(hdr);
+			if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
+				if (!acpi_sdt_check((uint8_t *) vhdr))
 					break;
 				
-				*signature_map[j].sdt_ptr = hdr;
+				*signature_map[j].sdt_ptr = vhdr;
 				LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
 				    signature_map[j].description);
@@ -144,10 +153,10 @@
 			    (struct acpi_sdt_header *) ((uintptr_t) acpi_xsdt->entry[i]);
 			
-			map_sdt(hdr);
-			if (CMP_SIGNATURE(hdr->signature, signature_map[j].signature)) {
-				if (!acpi_sdt_check((uint8_t *) hdr))
+			struct acpi_sdt_header *vhdr = map_sdt(hdr);
+			if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
+				if (!acpi_sdt_check((uint8_t *) vhdr))
 					break;
 				
-				*signature_map[j].sdt_ptr = hdr;
+				*signature_map[j].sdt_ptr = vhdr;
 				LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
 				    signature_map[j].description);
@@ -187,13 +196,17 @@
 	LOG("%p: ACPI Root System Description Pointer", acpi_rsdp);
 	
-	acpi_rsdt = (struct acpi_rsdt *) ((uintptr_t) acpi_rsdp->rsdt_address);
+	uintptr_t acpi_rsdt_p = (uintptr_t) acpi_rsdp->rsdt_address;
+	uintptr_t acpi_xsdt_p = 0;
+
 	if (acpi_rsdp->revision)
-		acpi_xsdt = (struct acpi_xsdt *) ((uintptr_t) acpi_rsdp->xsdt_address);
-	
-	if (acpi_rsdt)
-		map_sdt((struct acpi_sdt_header *) acpi_rsdt);
-	
-	if (acpi_xsdt)
-		map_sdt((struct acpi_sdt_header *) acpi_xsdt);
+		acpi_xsdt_p = (uintptr_t) acpi_rsdp->xsdt_address;
+	
+	if (acpi_rsdt_p)
+		acpi_rsdt = (struct acpi_rsdt *) map_sdt(
+		    (struct acpi_sdt_header *) acpi_rsdt_p);
+	
+	if (acpi_xsdt_p)
+		acpi_xsdt = (struct acpi_xsdt *) map_sdt(
+		    (struct acpi_sdt_header *) acpi_xsdt_p);
 	
 	if ((acpi_rsdt) && (!acpi_sdt_check((uint8_t *) acpi_rsdt))) {