diff --git a/xen/arch/arm/mpu/setup.c b/xen/arch/arm/mpu/setup.c
index b4da77003f..2ef703757f 100644
--- a/xen/arch/arm/mpu/setup.c
+++ b/xen/arch/arm/mpu/setup.c
@@ -1,17 +1,86 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <xen/bootfdt.h>
 #include <xen/bug.h>
 #include <xen/init.h>
+#include <xen/libfdt/libfdt.h>
 #include <xen/mm.h>
+#include <xen/pfn.h>
 #include <xen/types.h>
+#include <xen/sizes.h>
 #include <asm/setup.h>
 
+static paddr_t __initdata mapped_fdt_base = INVALID_PADDR;
+static paddr_t __initdata mapped_fdt_limit = INVALID_PADDR;
+
 void __init setup_pagetables(void) {}
 
 void * __init early_fdt_map(paddr_t fdt_paddr)
 {
-    BUG_ON("unimplemented");
-    return NULL;
+    /* Map at least a page containing the DTB address, exclusive range */
+    paddr_t base = round_pgdown(fdt_paddr);
+    paddr_t limit = round_pgup(fdt_paddr + sizeof(struct fdt_header));
+    unsigned int flags = PAGE_HYPERVISOR_RO;
+    void *fdt_virt = (void *)fdt_paddr; /* virt == paddr for MPU */
+    int rc;
+    uint32_t size;
+    unsigned long nr_mfns;
+
+    /*
+     * Check whether the physical FDT address is set and meets the minimum
+     * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be at
+     * least 8 bytes so that we always access the magic and size fields
+     * of the FDT header after mapping the first chunk, double check if
+     * that is indeed the case.
+     */
+    BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
+    if ( !fdt_paddr || fdt_paddr % MIN_FDT_ALIGN )
+        return NULL;
+
+    /*
+     * DTB at this address has already been mapped.`start_xen` calls this twice,
+     * before and after `setup_page_tables`, which is a no-op on MPU.
+     */
+    if ( mapped_fdt_base == fdt_paddr )
+        return fdt_virt;
+
+    ASSERT(mapped_fdt_base == INVALID_PADDR);
+
+    nr_mfns = (limit - base) >> PAGE_SHIFT;
+
+    rc = map_pages_to_xen(base, maddr_to_mfn(base), nr_mfns, flags);
+    if ( rc )
+        panic("Unable to map the device-tree\n");
+
+    mapped_fdt_base = fdt_paddr;
+    mapped_fdt_limit = limit;
+
+    if ( fdt_magic(fdt_virt) != FDT_MAGIC )
+        return NULL;
+
+    size = fdt_totalsize(fdt_virt);
+    if ( size > MAX_FDT_SIZE )
+        return NULL;
+
+    limit = round_pgup(fdt_paddr + size);
+
+    /* If the mapped range is not enough, map the rest of the DTB. */
+    if ( limit > mapped_fdt_limit )
+    {
+        rc = destroy_xen_mappings(base, mapped_fdt_limit);
+        if ( rc )
+            panic("Unable to unmap the device-tree header\n");
+
+        nr_mfns = (limit - base) >> PAGE_SHIFT;
+
+        rc = map_pages_to_xen(base, maddr_to_mfn(base), nr_mfns, flags);
+        if ( rc )
+            panic("Unable to map the device-tree\n");
+
+        mapped_fdt_limit = limit;
+    }
+
+    return fdt_virt;
 }
 
 /*