diff --git a/include/bl_common.h b/include/bl_common.h
new file mode 100644
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--- /dev/null
+++ b/include/bl_common.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2013, ARM Limited. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __BL_COMMON_H__
+#define __BL_COMMON_H__
+
+#define SECURE		0
+#define NON_SECURE	1
+
+#define UP	1
+#define DOWN	0
+
+/*******************************************************************************
+ * Constants for loading images. When BLx wants to load BLy, it looks at a
+ * meminfo structure to find the extents of free memory. Then depending upon
+ * how it has been configured, it can either load BLy at the top or bottom of
+ * the free memory. These constants indicate the choice.
+ * TODO: Make this configurable while building the trusted firmware.
+ ******************************************************************************/
+#define TOP_LOAD	0x1
+#define BOT_LOAD	!TOP_LOAD
+#define LOAD_MASK	(1 << 0)
+
+/*******************************************************************************
+ * Size of memory for sharing data while changing exception levels.
+ *
+ * There are 2 cases where this memory buffer is used:
+ *
+ *   - when BL1 (running in EL3) passes control to BL2 (running in S-EL1).
+ *     BL1 needs to pass the memory layout to BL2, to allow BL2 to find out
+ *     how much free trusted ram remains;
+ *
+ *   - when BL2 (running in S-EL1) passes control back to BL1 (running in EL3)
+ *     to make it run BL31.  BL2 needs to pass the memory layout, as well as
+ *     information on how to pass control to the non-trusted software image.
+ ******************************************************************************/
+#define EL_CHANGE_MEM_SIZE	(sizeof(meminfo) + sizeof(el_change_info))
+
+
+#ifndef __ASSEMBLY__
+/*******************************************************************************
+ * Structure used for telling the next BL how much of a particular type of
+ * memory is available for its use and how much is already used.
+ ******************************************************************************/
+typedef struct {
+	unsigned long total_base;
+	long total_size;
+	unsigned long free_base;
+	long free_size;
+	unsigned long attr;
+	unsigned long next;
+} meminfo;
+
+typedef struct {
+	unsigned long arg0;
+	unsigned long arg1;
+	unsigned long arg2;
+	unsigned long arg3;
+	unsigned long arg4;
+	unsigned long arg5;
+	unsigned long arg6;
+	unsigned long arg7;
+} aapcs64_params;
+
+/*******************************************************************************
+ * This structure represents the superset of information needed while switching
+ * exception levels. The only two mechanisms to do so are ERET & SMC. In case of
+ * SMC all members apart from 'aapcs64_params' will be ignored. The 'next'
+ * member is a placeholder for a complicated case in the distant future when BL2
+ * will load multiple BL3x images as well as a non-secure image. So multiple
+ * such structures will have to be passed to BL31 in S-EL3.
+ ******************************************************************************/
+typedef struct {
+	unsigned long entrypoint;
+	unsigned long spsr;
+	unsigned long security_state;
+	aapcs64_params args;
+	unsigned long next;
+} el_change_info;
+
+/*******************************************************************************
+ * Function & variable prototypes
+ ******************************************************************************/
+extern unsigned long page_align(unsigned long, unsigned);
+extern void change_security_state(unsigned int);
+extern int drop_el(aapcs64_params *, unsigned long, unsigned long);
+extern long raise_el(aapcs64_params *);
+extern long change_el(el_change_info *);
+extern unsigned long make_spsr(unsigned long, unsigned long, unsigned long);
+extern void init_bl2_mem_layout(meminfo *,
+			        meminfo *,
+			        unsigned int,
+			        unsigned long) __attribute__((weak));
+extern void init_bl31_mem_layout(const meminfo *,
+				 meminfo *,
+				 unsigned int) __attribute__((weak));
+extern unsigned long load_image(meminfo *, const char *, unsigned int, unsigned long);
+extern int run_image(unsigned long,
+		     unsigned long,
+		     unsigned long,
+		     meminfo *,
+		     void *);
+extern unsigned long *get_el_change_mem_ptr(void);
+
+#endif /*__ASSEMBLY__*/
+
+#endif /* __BL_COMMON_H__ */