diff --git a/arch/Kconfig b/arch/Kconfig
index 5c6aee3ea4c..dc3845b21a2 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -62,6 +62,7 @@ config X86
 	select ARCH_HAS_TIMING_FUNCTIONS
 	select ARCH_HAS_THREAD_LOCAL_STORAGE
 	select ARCH_HAS_DEMAND_PAGING
+	select ARCH_MAPS_ALL_RAM
 	help
 	  x86 architecture
 
@@ -532,6 +533,26 @@ config ARCH_HAS_RESERVED_PAGE_FRAMES
 	  memory mappings. The architecture will need to implement
 	  arch_reserved_pages_update().
 
+config ARCH_MAPS_ALL_RAM
+	bool
+	help
+	  This hidden option is selected by the architecture to inform the kernel
+	  that all RAM is mapped at boot, and not just the bounds of the Zephyr image.
+	  If RAM starts at 0x0, the first page must remain un-mapped to catch NULL
+	  pointer dereferences. With this enabled, the kernel will not assume that
+	  virtual memory addresses past the kernel image are available for mappings,
+	  but instead takes into account an entire RAM mapping instead.
+
+	  This is typically set by architectures which need direct access to all memory.
+	  It is the architecture's responsibility to mark reserved memory regions
+	  as such in arch_reserved_pages_update().
+
+	  Although the kernel will not disturb this RAM mapping by re-mapping the associated
+	  virtual addresses elsewhere, this is limited to only management of the
+	  virtual address space. The kernel's page frame ontology will not consider
+	  this mapping at all; non-kernel pages will be considered free (unless marked
+	  as reserved) and Z_PAGE_FRAME_MAPPED will not be set.
+
 menuconfig MMU
 	bool "Enable MMU features"
 	depends on CPU_HAS_MMU
diff --git a/kernel/include/mmu.h b/kernel/include/mmu.h
index 003d1d6062e..50981e3ecf3 100644
--- a/kernel/include/mmu.h
+++ b/kernel/include/mmu.h
@@ -40,6 +40,22 @@
 #define Z_KERNEL_VIRT_END	((uint8_t *)(&z_mapped_end))
 #define Z_KERNEL_VIRT_SIZE	((size_t)(&z_mapped_size))
 
+#define Z_VM_OFFSET	 ((CONFIG_KERNEL_VM_BASE + CONFIG_KERNEL_VM_OFFSET) - \
+			  CONFIG_SRAM_BASE_ADDRESS)
+
+/* Only applies to boot RAM mappings within the Zephyr image that have never
+ * been remapped or paged out. Never use this unless you know exactly what you
+ * are doing.
+ */
+#define Z_BOOT_VIRT_TO_PHYS(virt) ((uintptr_t)(((uint8_t *)virt) + Z_VM_OFFSET))
+#define Z_BOOT_PHYS_TO_VIRT(phys) ((uint8_t *)(((uintptr_t)phys) - Z_VM_OFFSET))
+
+#ifdef CONFIG_ARCH_MAPS_ALL_RAM
+#define Z_FREE_VM_START	Z_BOOT_PHYS_TO_VIRT(Z_PHYS_RAM_END)
+#else
+#define Z_FREE_VM_START	Z_KERNEL_VIRT_END
+#endif
+
 /*
  * Macros and data structures for physical page frame accounting,
  * APIs for use by eviction and backing store algorithms. This code
diff --git a/kernel/mmu.c b/kernel/mmu.c
index 0c8c61fb719..88c40025873 100644
--- a/kernel/mmu.c
+++ b/kernel/mmu.c
@@ -125,25 +125,32 @@ void z_page_frames_dump(void)
 	for (_pos = _base; \
 	     _pos < ((uintptr_t)_base + _size); _pos += CONFIG_MMU_PAGE_SIZE)
 
+
 /*
  * Virtual address space management
  *
  * Call all of these functions with z_mm_lock held.
  *
  * Overall virtual memory map: When the kernel starts, it resides in
- * virtual memory in the region Z_BOOT_KERNEL_VIRT_START to
- * Z_BOOT_KERNEL_VIRT_END. Unused virtual memory past this, up to the limit
+ * virtual memory in the region Z_KERNEL_VIRT_START to
+ * Z_KERNEL_VIRT_END. Unused virtual memory past this, up to the limit
  * noted by CONFIG_KERNEL_VM_SIZE may be used for runtime memory mappings.
  *
+ * If CONFIG_ARCH_MAPS_ALL_RAM is set, we do not just map the kernel image,
+ * but have a mapping for all RAM in place. This is for special architectural
+ * purposes and does not otherwise affect page frame accounting or flags;
+ * the only guarantee is that such RAM mapping outside of the Zephyr image
+ * won't be disturbed by subsequent memory mapping calls.
+ *
  * +--------------+ <- Z_VIRT_ADDR_START
  * | Undefined VM | <- May contain ancillary regions like x86_64's locore
- * +--------------+ <- Z_BOOT_KERNEL_VIRT_START (often == Z_VIRT_ADDR_START)
+ * +--------------+ <- Z_KERNEL_VIRT_START (often == Z_VIRT_ADDR_START)
  * | Mapping for  |
  * | main kernel  |
  * | image        |
  * |		  |
  * |		  |
- * +--------------+ <- Z_BOOT_KERNEL_VIRT_END
+ * +--------------+ <- Z_FREE_VM_START
  * |              |
  * | Unused,      |
  * | Available VM |
@@ -175,7 +182,7 @@ static void *virt_region_get(size_t size)
 {
 	uint8_t *dest_addr;
 
-	if ((mapping_pos - size) < Z_KERNEL_VIRT_END) {
+	if ((mapping_pos - size) < Z_FREE_VM_START) {
 		LOG_ERR("insufficient virtual address space (requested %zu)",
 			size);
 		return NULL;
@@ -474,14 +481,6 @@ size_t k_mem_region_align(uintptr_t *aligned_phys, size_t *aligned_size,
 	return addr_offset;
 }
 
-#define VM_OFFSET	 ((CONFIG_KERNEL_VM_BASE + CONFIG_KERNEL_VM_OFFSET) - \
-			  CONFIG_SRAM_BASE_ADDRESS)
-
-/* Only applies to boot RAM mappings within the Zephyr image that have never
- * been remapped or paged out. Never use this unless you know exactly what you
- * are doing.
- */
-#define BOOT_VIRT_TO_PHYS(virt) ((uintptr_t)(((uint8_t *)virt) + VM_OFFSET))
 
 #ifdef CONFIG_USERSPACE
 void z_kernel_map_fixup(void)
@@ -500,7 +499,7 @@ void z_kernel_map_fixup(void)
 
 	if (kobject_size != 0) {
 		arch_mem_map(kobject_page_begin,
-			     BOOT_VIRT_TO_PHYS(kobject_page_begin),
+			     Z_BOOT_VIRT_TO_PHYS(kobject_page_begin),
 			     kobject_size, K_MEM_PERM_RW | K_MEM_CACHE_WB);
 	}
 }
@@ -527,7 +526,7 @@ void z_mem_manage_init(void)
 	 */
 	VIRT_FOREACH(Z_KERNEL_VIRT_START, Z_KERNEL_VIRT_SIZE, addr)
 	{
-		pf = z_phys_to_page_frame(BOOT_VIRT_TO_PHYS(addr));
+		pf = z_phys_to_page_frame(Z_BOOT_VIRT_TO_PHYS(addr));
 		frame_mapped_set(pf, addr);
 
 		/* TODO: for now we pin the whole Zephyr image. Demand paging
diff --git a/tests/kernel/mem_protect/syscalls/CMakeLists.txt b/tests/kernel/mem_protect/syscalls/CMakeLists.txt
index a34f3f7a837..55684803bba 100644
--- a/tests/kernel/mem_protect/syscalls/CMakeLists.txt
+++ b/tests/kernel/mem_protect/syscalls/CMakeLists.txt
@@ -4,5 +4,10 @@ cmake_minimum_required(VERSION 3.13.1)
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 project(syscalls)
 
+target_include_directories(app PRIVATE
+  ${ZEPHYR_BASE}/kernel/include
+  ${ZEPHYR_BASE}/arch/${ARCH}/include
+  )
+
 FILE(GLOB app_sources src/*.c)
 target_sources(app PRIVATE ${app_sources})
diff --git a/tests/kernel/mem_protect/syscalls/src/main.c b/tests/kernel/mem_protect/syscalls/src/main.c
index 69f2f3d0c2f..c6d2cfef58a 100644
--- a/tests/kernel/mem_protect/syscalls/src/main.c
+++ b/tests/kernel/mem_protect/syscalls/src/main.c
@@ -9,6 +9,7 @@
 #include <ztest.h>
 #include <linker/linker-defs.h>
 #include "test_syscalls.h"
+#include <mmu.h>
 
 #define BUF_SIZE	32
 #define SLEEP_MS_LONG	15000
@@ -18,7 +19,7 @@
 #define FAULTY_ADDRESS 0x0FFFFFFF
 #elif CONFIG_MMU
 /* Just past the zephyr image mapping should be a non-present page */
-#define FAULTY_ADDRESS ((uint8_t *)(&z_mapped_end))
+#define FAULTY_ADDRESS Z_FREE_VM_START
 #else
 #define FAULTY_ADDRESS 0xFFFFFFF0
 #endif