diff --git a/arch/mips/jz4740/setup.c b/arch/mips/jz4740/setup.c
index 6a9e14dab91e..d97cfbf882f5 100644
--- a/arch/mips/jz4740/setup.c
+++ b/arch/mips/jz4740/setup.c
@@ -1,5 +1,6 @@
 /*
  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  Copyright (C) 2011, Maarten ter Huurne <maarten@treewalker.org>
  *  JZ4740 setup code
  *
  *  This program is free software; you can redistribute it and/or modify it
@@ -14,13 +15,44 @@
  */
 
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/kernel.h>
 
+#include <asm/bootinfo.h>
+
+#include <asm/mach-jz4740/base.h>
+
 #include "reset.h"
 
+
+#define JZ4740_EMC_SDRAM_CTRL 0x80
+
+
+static void __init jz4740_detect_mem(void)
+{
+	void __iomem *jz_emc_base;
+	u32 ctrl, bus, bank, rows, cols;
+	phys_t size;
+
+	jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
+	ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
+	bus = 2 - ((ctrl >> 31) & 1);
+	bank = 1 + ((ctrl >> 19) & 1);
+	cols = 8 + ((ctrl >> 26) & 7);
+	rows = 11 + ((ctrl >> 20) & 3);
+	printk(KERN_DEBUG
+		"SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
+		bus, bank, rows, cols);
+	iounmap(jz_emc_base);
+
+	size = 1 << (bus + bank + cols + rows);
+	add_memory_region(0, size, BOOT_MEM_RAM);
+}
+
 void __init plat_mem_setup(void)
 {
 	jz4740_reset_init();
+	jz4740_detect_mem();
 }
 
 const char *get_system_type(void)