diff --git a/arch/mips/mti-malta/malta-dtshim.c b/arch/mips/mti-malta/malta-dtshim.c
index 151f488..bdda3cb 100644
--- a/arch/mips/mti-malta/malta-dtshim.c
+++ b/arch/mips/mti-malta/malta-dtshim.c
@@ -13,18 +13,64 @@
 #include <linux/libfdt.h>
 #include <linux/of_fdt.h>
 #include <linux/sizes.h>
+#include <asm/addrspace.h>
 #include <asm/bootinfo.h>
 #include <asm/fw/fw.h>
+#include <asm/mips-boards/generic.h>
 #include <asm/page.h>
 
+#define ROCIT_REG_BASE			0x1f403000
+#define ROCIT_CONFIG_GEN1		(ROCIT_REG_BASE + 0x04)
+#define  ROCIT_CONFIG_GEN1_MEMMAP_SHIFT	8
+#define  ROCIT_CONFIG_GEN1_MEMMAP_MASK	(0xf << 8)
+
 static unsigned char fdt_buf[16 << 10] __initdata;
 
 /* determined physical memory size, not overridden by command line args	 */
 extern unsigned long physical_memsize;
 
-#define MAX_MEM_ARRAY_ENTRIES 1
+enum mem_map {
+	MEM_MAP_V1 = 0,
+	MEM_MAP_V2,
+};
 
-static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size)
+#define MAX_MEM_ARRAY_ENTRIES 2
+
+static __init int malta_scon(void)
+{
+	int scon = MIPS_REVISION_SCONID;
+
+	if (scon != MIPS_REVISION_SCON_OTHER)
+		return scon;
+
+	switch (MIPS_REVISION_CORID) {
+	case MIPS_REVISION_CORID_QED_RM5261:
+	case MIPS_REVISION_CORID_CORE_LV:
+	case MIPS_REVISION_CORID_CORE_FPGA:
+	case MIPS_REVISION_CORID_CORE_FPGAR2:
+		return MIPS_REVISION_SCON_GT64120;
+
+	case MIPS_REVISION_CORID_CORE_EMUL_BON:
+	case MIPS_REVISION_CORID_BONITO64:
+	case MIPS_REVISION_CORID_CORE_20K:
+		return MIPS_REVISION_SCON_BONITO;
+
+	case MIPS_REVISION_CORID_CORE_MSC:
+	case MIPS_REVISION_CORID_CORE_FPGA2:
+	case MIPS_REVISION_CORID_CORE_24K:
+		return MIPS_REVISION_SCON_SOCIT;
+
+	case MIPS_REVISION_CORID_CORE_FPGA3:
+	case MIPS_REVISION_CORID_CORE_FPGA4:
+	case MIPS_REVISION_CORID_CORE_FPGA5:
+	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+	default:
+		return MIPS_REVISION_SCON_ROCIT;
+	}
+}
+
+static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size,
+					 enum mem_map map)
 {
 	unsigned long size_preio;
 	unsigned entries;
@@ -39,11 +85,47 @@
 		 * DDR but limits it to 2GB.
 		 */
 		mem_array[1] = cpu_to_be32(size);
-	} else {
-		size_preio = min_t(unsigned long, size, SZ_256M);
-		mem_array[1] = cpu_to_be32(size_preio);
+		goto done;
 	}
 
+	size_preio = min_t(unsigned long, size, SZ_256M);
+	mem_array[1] = cpu_to_be32(size_preio);
+	size -= size_preio;
+	if (!size)
+		goto done;
+
+	if (map == MEM_MAP_V2) {
+		/*
+		 * We have a flat 32 bit physical memory map with DDR filling
+		 * all 4GB of the memory map, apart from the I/O region which
+		 * obscures 256MB from 0x10000000-0x1fffffff.
+		 *
+		 * Therefore we discard the 256MB behind the I/O region.
+		 */
+		if (size <= SZ_256M)
+			goto done;
+		size -= SZ_256M;
+
+		/* Make use of the memory following the I/O region */
+		entries++;
+		mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_512M);
+		mem_array[3] = cpu_to_be32(size);
+	} else {
+		/*
+		 * We have a 32 bit physical memory map with a 2GB DDR region
+		 * aliased in the upper & lower halves of it. The I/O region
+		 * obscures 256MB from 0x10000000-0x1fffffff in the low alias
+		 * but the DDR it obscures is accessible via the high alias.
+		 *
+		 * Simply access everything beyond the lowest 256MB of DDR using
+		 * the high alias.
+		 */
+		entries++;
+		mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_2G + SZ_256M);
+		mem_array[3] = cpu_to_be32(size);
+	}
+
+done:
 	BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
 	return entries;
 }
@@ -54,6 +136,8 @@
 	unsigned long memsize;
 	unsigned mem_entries;
 	int i, err, mem_off;
+	enum mem_map mem_map;
+	u32 config;
 	char *var, param_name[10], *var_names[] = {
 		"ememsize", "memsize",
 	};
@@ -106,6 +190,20 @@
 	/* if the user says there's more RAM than we thought, believe them */
 	physical_memsize = max_t(unsigned long, physical_memsize, memsize);
 
+	/* detect the memory map in use */
+	if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
+		/* ROCit has a register indicating the memory map in use */
+		config = readl((void __iomem *)CKSEG1ADDR(ROCIT_CONFIG_GEN1));
+		mem_map = config & ROCIT_CONFIG_GEN1_MEMMAP_MASK;
+		mem_map >>= ROCIT_CONFIG_GEN1_MEMMAP_SHIFT;
+	} else {
+		/* if not using ROCit, presume the v1 memory map */
+		mem_map = MEM_MAP_V1;
+	}
+	if (mem_map > MEM_MAP_V2)
+		panic("Unsupported physical memory map v%u detected",
+		      (unsigned int)mem_map);
+
 	/* append memory to the DT */
 	mem_off = fdt_add_subnode(fdt, root_off, "memory");
 	if (mem_off < 0)
@@ -115,13 +213,13 @@
 	if (err)
 		panic("Unable to set memory node device_type: %d", err);
 
-	mem_entries = gen_fdt_mem_array(mem_array, physical_memsize);
+	mem_entries = gen_fdt_mem_array(mem_array, physical_memsize, mem_map);
 	err = fdt_setprop(fdt, mem_off, "reg", mem_array,
 			  mem_entries * 2 * sizeof(mem_array[0]));
 	if (err)
 		panic("Unable to set memory regs property: %d", err);
 
-	mem_entries = gen_fdt_mem_array(mem_array, memsize);
+	mem_entries = gen_fdt_mem_array(mem_array, memsize, mem_map);
 	err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
 			  mem_entries * 2 * sizeof(mem_array[0]));
 	if (err)