diff --git a/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h b/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
index 9f4458c8e070..22d6c9a6e4ca 100644
--- a/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
+++ b/arch/arm/mach-ep93xx/include/mach/ep93xx-regs.h
@@ -5,6 +5,40 @@
 #ifndef __ASM_ARCH_EP93XX_REGS_H
 #define __ASM_ARCH_EP93XX_REGS_H
 
+/*
+ * EP93xx Physical Memory Map:
+ *
+ * The ASDO pin is sampled at system reset to select a synchronous or
+ * asynchronous boot configuration.  When ASDO is "1" (i.e. pulled-up)
+ * the synchronous boot mode is selected.  When ASDO is "0" (i.e
+ * pulled-down) the asynchronous boot mode is selected.
+ *
+ * In synchronous boot mode nSDCE3 is decoded starting at physical address
+ * 0x00000000 and nCS0 is decoded starting at 0xf0000000.  For asynchronous
+ * boot mode they are swapped with nCS0 decoded at 0x00000000 ann nSDCE3
+ * decoded at 0xf0000000.
+ *
+ * There is known errata for the EP93xx dealing with External Memory
+ * Configurations.  Please refer to "AN273: EP93xx Silicon Rev E Design
+ * Guidelines" for more information.  This document can be found at:
+ *
+ *	http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+ */
+
+#define EP93XX_CS0_PHYS_BASE_ASYNC	0x00000000	/* ASDO Pin = 0 */
+#define EP93XX_SDCE3_PHYS_BASE_SYNC	0x00000000	/* ASDO Pin = 1 */
+#define EP93XX_CS1_PHYS_BASE		0x10000000
+#define EP93XX_CS2_PHYS_BASE		0x20000000
+#define EP93XX_CS3_PHYS_BASE		0x30000000
+#define EP93XX_PCMCIA_PHYS_BASE		0x40000000
+#define EP93XX_CS6_PHYS_BASE		0x60000000
+#define EP93XX_CS7_PHYS_BASE		0x70000000
+#define EP93XX_SDCE0_PHYS_BASE		0xc0000000
+#define EP93XX_SDCE1_PHYS_BASE		0xd0000000
+#define EP93XX_SDCE2_PHYS_BASE		0xe0000000
+#define EP93XX_SDCE3_PHYS_BASE_ASYNC	0xf0000000	/* ASDO Pin = 0 */
+#define EP93XX_CS0_PHYS_BASE_SYNC	0xf0000000	/* ASDO Pin = 1 */
+
 /*
  * EP93xx linux memory map:
  *