diff --git a/tools/libxc/xc_dom_arm.c b/tools/libxc/xc_dom_arm.c
index 36b1487..65464c7 100644
--- a/tools/libxc/xc_dom_arm.c
+++ b/tools/libxc/xc_dom_arm.c
@@ -18,6 +18,7 @@
  * Copyright (c) 2011, Citrix Systems
  */
 #include <inttypes.h>
+#include <assert.h>
 
 #include <xen/xen.h>
 #include <xen/io/protocols.h>
@@ -245,28 +246,73 @@ static int set_mode(xc_interface *xch, domid_t domid, char *guest_type)
     return rc;
 }
 
+static int populate_guest_memory(struct xc_dom_image *dom,
+                                 xen_pfn_t base_pfn, xen_pfn_t nr_pfns)
+{
+    int rc;
+    xen_pfn_t allocsz, pfn;
+
+    if (!nr_pfns)
+        return 0;
+
+    DOMPRINTF("%s: populating RAM @ %016"PRIx64"-%016"PRIx64" (%"PRId64"MB)",
+              __FUNCTION__,
+              (uint64_t)base_pfn << XC_PAGE_SHIFT,
+              (uint64_t)(base_pfn + nr_pfns) << XC_PAGE_SHIFT,
+              (uint64_t)nr_pfns >> (20-XC_PAGE_SHIFT));
+
+    for ( pfn = 0; pfn < nr_pfns; pfn++ )
+        dom->p2m_host[pfn] = base_pfn + pfn;
+
+    for ( pfn = rc = allocsz = 0; (pfn < nr_pfns) && !rc; pfn += allocsz )
+    {
+        allocsz = nr_pfns - pfn;
+        if ( allocsz > 1024*1024 )
+            allocsz = 1024*1024;
+
+        rc = xc_domain_populate_physmap_exact(
+            dom->xch, dom->guest_domid, allocsz,
+            0, 0, &dom->p2m_host[pfn]);
+    }
+
+    return rc;
+}
+
 int arch_setup_meminit(struct xc_dom_image *dom)
 {
     int rc;
-    xen_pfn_t pfn, allocsz, i;
+    xen_pfn_t pfn;
     uint64_t modbase;
 
     /* Convenient */
-    const uint64_t rambase = dom->rambase_pfn << XC_PAGE_SHIFT;
-    const uint64_t ramend = rambase + ( dom->total_pages << XC_PAGE_SHIFT );
+    const uint64_t ramsize = (uint64_t)dom->total_pages << XC_PAGE_SHIFT;
+
+    const uint64_t ram0size =
+        ramsize > GUEST_RAM0_SIZE ? GUEST_RAM0_SIZE : ramsize;
+    const uint64_t ram0end = GUEST_RAM0_BASE + ram0size;
+    const uint64_t ram1size =
+        ramsize > ram0size ? ramsize - ram0size : 0;
+    const uint64_t ram1end = GUEST_RAM1_BASE + ram1size;
+
+    const xen_pfn_t p2m_size = ram1size ?
+        (ram1end - GUEST_RAM0_BASE) >> XC_PAGE_SHIFT :
+        (ram0end - GUEST_RAM0_BASE) >> XC_PAGE_SHIFT;
+
     const uint64_t kernend = ROUNDUP(dom->kernel_seg.vend, 21/*2MB*/);
     const uint64_t dtb_size = dom->devicetree_blob ?
         ROUNDUP(dom->devicetree_size, XC_PAGE_SHIFT) : 0;
     const uint64_t ramdisk_size = dom->ramdisk_blob ?
         ROUNDUP(dom->ramdisk_size, XC_PAGE_SHIFT) : 0;
     const uint64_t modsize = dtb_size + ramdisk_size;
-    const uint64_t ram128mb = rambase + (128<<20);
+    const uint64_t ram128mb = GUEST_RAM0_BASE + (128<<20);
 
-    if ( ramend - 1 > GUEST_RAM_END )
+    assert(dom->rambase_pfn << XC_PAGE_SHIFT == GUEST_RAM0_BASE);
+
+    if ( ramsize > GUEST_RAM_MAX )
     {
         DOMPRINTF("%s: ram size is too large for guest address space: "
                   "%"PRIx64" > %"PRIx64,
-                  __FUNCTION__, ramend, GUEST_RAM_END);
+                  __FUNCTION__, ramsize, GUEST_RAM_MAX);
         return -1;
     }
 
@@ -276,38 +322,31 @@ int arch_setup_meminit(struct xc_dom_image *dom)
 
     dom->shadow_enabled = 1;
 
-    dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) * dom->total_pages);
+    dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) * p2m_size);
     if ( dom->p2m_host == NULL )
         return -EINVAL;
+    for ( pfn = 0; pfn < p2m_size; pfn++ )
+        dom->p2m_host[pfn] = INVALID_MFN;
 
-    /* setup initial p2m */
-    for ( pfn = 0; pfn < dom->total_pages; pfn++ )
-        dom->p2m_host[pfn] = pfn + dom->rambase_pfn;
-
-    /* allocate guest memory */
-    for ( i = rc = allocsz = 0;
-          (i < dom->total_pages) && !rc;
-          i += allocsz )
-    {
-        allocsz = dom->total_pages - i;
-        if ( allocsz > 1024*1024 )
-            allocsz = 1024*1024;
-
-        rc = xc_domain_populate_physmap_exact(
-            dom->xch, dom->guest_domid, allocsz,
-            0, 0, &dom->p2m_host[i]);
-    }
-
+    /* setup initial p2m and allocate guest memory */
+    if ((rc = populate_guest_memory(dom,
+                                    GUEST_RAM0_BASE >> XC_PAGE_SHIFT,
+                                    ram0size >> XC_PAGE_SHIFT)))
+        return rc;
+    if ((rc = populate_guest_memory(dom,
+                                    GUEST_RAM1_BASE >> XC_PAGE_SHIFT,
+                                    ram1size >> XC_PAGE_SHIFT)))
+        return rc;
 
     /*
-     * Place boot modules at 128MB into RAM if there is enough RAM and
+     * Place boot modules at 128MB into low RAM if there is enough RAM and
      * the kernel does not overlap. Otherwise place them immediately
      * after the kernel. If there is no space after the kernel then
      * there is insufficient RAM and we fail.
      */
-    if ( ramend >= ram128mb + modsize && kernend < ram128mb )
+    if ( ram0end >= ram128mb + modsize && kernend < ram128mb )
         modbase = ram128mb;
-    else if ( ramend >= kernend + modsize )
+    else if ( ram0end >= kernend + modsize )
         modbase = kernend;
     else
         return -1;
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 4f0f0e2..6170454 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -255,9 +255,9 @@ static int make_psci_node(libxl__gc *gc, void *fdt)
     return 0;
 }
 
-static int make_memory_node(libxl__gc *gc, void *fdt,
-                            unsigned long long base,
-                            unsigned long long size)
+static int make_one_memory_node(libxl__gc *gc, void *fdt,
+                                unsigned long long base,
+                                unsigned long long size)
 {
     int res;
     const char *name = GCSPRINTF("memory@%08llx", base);
@@ -269,7 +269,7 @@ static int make_memory_node(libxl__gc *gc, void *fdt,
     if (res) return res;
 
     res = fdt_property_regs(gc, fdt, ROOT_ADDRESS_CELLS, ROOT_SIZE_CELLS,
-                            1, (uint64_t)base, (uint64_t)size);
+                            1, base, size);
     if (res) return res;
 
     res = fdt_end_node(fdt);
@@ -278,6 +278,24 @@ static int make_memory_node(libxl__gc *gc, void *fdt,
     return 0;
 }
 
+static int make_memory_node(libxl__gc *gc, void *fdt,
+                            unsigned long long size)
+{
+    int res;
+    /* This had better match libxc's arch_setup_meminit... */
+    const uint64_t size0 = size > GUEST_RAM0_SIZE ? GUEST_RAM0_SIZE : size;
+    const uint64_t size1 = size > GUEST_RAM0_SIZE ? size - size0 : 0;
+
+    res = make_one_memory_node(gc, fdt, GUEST_RAM0_BASE, size0);
+    if (res) return res;
+    if (size1) {
+        res = make_one_memory_node(gc, fdt, GUEST_RAM1_BASE, size1);
+        if (res) return res;
+    }
+
+    return 0;
+}
+
 static int make_intc_node(libxl__gc *gc, void *fdt,
                           unsigned long long gicd_base,
                           unsigned long long gicd_size,
@@ -493,7 +511,6 @@ next_resize:
         FDT( make_psci_node(gc, fdt) );
 
         FDT( make_memory_node(gc, fdt,
-                              dom->rambase_pfn << XC_PAGE_SHIFT,
                               info->target_memkb * 1024) );
         FDT( make_intc_node(gc, fdt,
                             GUEST_GICD_BASE, GUEST_GICD_SIZE,
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 5840453..d15a977 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -374,8 +374,17 @@ typedef uint64_t xen_callback_t;
 
 #define GUEST_MAGIC_BASE  0x39000000ULL
 
-#define GUEST_RAM_BASE    0x40000000ULL /* 3GB of RAM @ 1GB */
-#define GUEST_RAM_END     0xffffffffULL
+#define GUEST_RAM0_BASE   0x40000000ULL /* 3GB of low RAM @ 1GB */
+#define GUEST_RAM0_SIZE   0xc0000000ULL
+#define GUEST_RAM0_END    0xffffffffULL
+
+#define GUEST_RAM1_BASE   0x0200000000ULL /* 1016GB of RAM @ 8GB */
+#define GUEST_RAM1_SIZE   0xfe00000000ULL
+#define GUEST_RAM1_END    0xffffffffffULL
+
+#define GUEST_RAM_BASE    GUEST_RAM0_BASE /* Lowest RAM address */
+ /* Largest amount of actual RAM, not including holes */
+#define GUEST_RAM_MAX     (GUEST_RAM0_SIZE + GUEST_RAM1_SIZE)
 
 /* Interrupts */
 #define GUEST_TIMER_VIRT_PPI    27
