diff --git a/arch/x86/core/multiboot.c b/arch/x86/core/multiboot.c
index 27240b1b2eb..cdf0a71cbd9 100644
--- a/arch/x86/core/multiboot.c
+++ b/arch/x86/core/multiboot.c
@@ -28,8 +28,25 @@ static inline void clear_memmap(int index)
 	}
 }
 
-void z_multiboot_init(struct multiboot_info *info)
+void z_multiboot_init(struct multiboot_info *info_pa)
 {
+	struct multiboot_info *info;
+
+#if defined(CONFIG_ARCH_MAPS_ALL_RAM) || !defined(CONFIG_X86_MMU)
+	/*
+	 * Since the struct from bootloader resides in memory
+	 * and all memory is mapped, there is no need to
+	 * manually map it before accessing.
+	 *
+	 * Without MMU, all memory are identity-mapped already
+	 * so there is no need to map them again.
+	 */
+	info = info_pa;
+#else
+	z_phys_map((uint8_t **)&info, POINTER_TO_UINT(info_pa),
+		   sizeof(*info_pa), K_MEM_CACHE_NONE);
+#endif /* CONFIG_ARCH_MAPS_ALL_RAM */
+
 	if (info != NULL) {
 		memcpy(&multiboot_info, info, sizeof(*info));
 	}
@@ -42,12 +59,26 @@ void z_multiboot_init(struct multiboot_info *info)
 
 	if ((info->flags & MULTIBOOT_INFO_FLAGS_MMAP) &&
 	    (x86_memmap_source < X86_MEMMAP_SOURCE_MULTIBOOT_MMAP)) {
-		uint32_t address = info->mmap_addr;
+		uintptr_t address;
+		uintptr_t address_end;
 		struct multiboot_mmap *mmap;
 		int index = 0;
 		uint32_t type;
 
-		while ((address < (info->mmap_addr + info->mmap_length)) &&
+#if defined(CONFIG_ARCH_MAPS_ALL_RAM) || !defined(CONFIG_X86_MMU)
+		address = info->mmap_addr;
+#else
+		uint8_t *address_va;
+
+		z_phys_map(&address_va, info->mmap_addr, info->mmap_length,
+			   K_MEM_CACHE_NONE);
+
+		address = POINTER_TO_UINT(address_va);
+#endif /* CONFIG_ARCH_MAPS_ALL_RAM */
+
+		address_end = address + info->mmap_length;
+
+		while ((address < address_end) &&
 		       (index < CONFIG_X86_MEMMAP_ENTRIES)) {
 			mmap = UINT_TO_POINTER(address);