diff --git a/Makefile b/Makefile
index 267fc82..a7d3a87 100644
--- a/Makefile
+++ b/Makefile
@@ -162,11 +162,13 @@
 include lib/stdlib/stdlib.mk
 
 BL_COMMON_SOURCES	+=	common/bl_common.c			\
+				common/tf_log.c				\
 				common/tf_printf.c			\
 				common/tf_snprintf.c			\
 				common/${ARCH}/debug.S			\
 				lib/${ARCH}/cache_helpers.S		\
 				lib/${ARCH}/misc_helpers.S		\
+				plat/common/plat_log_common.c		\
 				plat/common/${ARCH}/plat_common.c	\
 				plat/common/${ARCH}/platform_helpers.S	\
 				${COMPILER_RT_SRCS}			\
diff --git a/common/tf_log.c b/common/tf_log.c
new file mode 100644
index 0000000..54c0a43
--- /dev/null
+++ b/common/tf_log.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <debug.h>
+#include <platform.h>
+
+/* Set the default maximum log level to the `LOG_LEVEL` build flag */
+static unsigned int max_log_level = LOG_LEVEL;
+
+/*
+ * The common log function which is invoked by ARM Trusted Firmware code.
+ * This function should not be directly invoked and is meant to be
+ * only used by the log macros defined in debug.h. The function
+ * expects the first character in the format string to be one of the
+ * LOG_MARKER_* macros defined in debug.h.
+ */
+void tf_log(const char *fmt, ...)
+{
+	unsigned int log_level;
+	va_list args;
+	const char *prefix_str;
+
+	/* We expect the LOG_MARKER_* macro as the first character */
+	log_level = fmt[0];
+
+	/* Verify that log_level is one of LOG_MARKER_* macro defined in debug.h */
+	assert(log_level && log_level <= LOG_LEVEL_VERBOSE);
+	assert(log_level % 10 == 0);
+
+	if (log_level > max_log_level)
+		return;
+
+	prefix_str = plat_log_get_prefix(log_level);
+
+	if (prefix_str != NULL)
+		tf_string_print(prefix_str);
+
+	va_start(args, fmt);
+	tf_vprintf(fmt+1, args);
+	va_end(args);
+}
+
+/*
+ * The helper function to set the log level dynamically by platform. The
+ * maximum log level is determined by `LOG_LEVEL` build flag at compile time
+ * and this helper can set a lower log level than the one at compile.
+ */
+void tf_log_set_max_level(unsigned int log_level)
+{
+	assert(log_level <= LOG_LEVEL_VERBOSE);
+	assert((log_level % 10) == 0);
+
+	/* Cap log_level to the compile time maximum. */
+	if (log_level < LOG_LEVEL)
+		max_log_level = log_level;
+
+}
diff --git a/common/tf_printf.c b/common/tf_printf.c
index c18e2f9..f73842a 100644
--- a/common/tf_printf.c
+++ b/common/tf_printf.c
@@ -23,8 +23,10 @@
 	(((lcount) > 1) ? va_arg(args, unsigned long long int) :	\
 	((lcount) ? va_arg(args, unsigned long int) : va_arg(args, unsigned int)))
 
-static void string_print(const char *str)
+void tf_string_print(const char *str)
 {
+	assert(str);
+
 	while (*str)
 		putchar(*str++);
 }
@@ -64,15 +66,13 @@
  * The print exits on all other formats specifiers other than valid
  * combinations of the above specifiers.
  *******************************************************************/
-void tf_printf(const char *fmt, ...)
+void tf_vprintf(const char *fmt, va_list args)
 {
-	va_list args;
 	int l_count;
 	long long int num;
 	unsigned long long int unum;
 	char *str;
 
-	va_start(args, fmt);
 	while (*fmt) {
 		l_count = 0;
 
@@ -94,12 +94,12 @@
 				break;
 			case 's':
 				str = va_arg(args, char *);
-				string_print(str);
+				tf_string_print(str);
 				break;
 			case 'p':
 				unum = (uintptr_t)va_arg(args, void *);
 				if (unum)
-					string_print("0x");
+					tf_string_print("0x");
 
 				unsigned_num_print(unum, 16);
 				break;
@@ -123,13 +123,20 @@
 				break;
 			default:
 				/* Exit on any other format specifier */
-				goto exit;
+				return;
 			}
 			fmt++;
 			continue;
 		}
 		putchar(*fmt++);
 	}
-exit:
-	va_end(args);
+}
+
+void tf_printf(const char *fmt, ...)
+{
+	va_list va;
+
+	va_start(va, fmt);
+	tf_vprintf(fmt, va);
+	va_end(va);
 }
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index c8d61ed..9798566 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -1014,6 +1014,21 @@
 next image. This function is currently invoked in BL2 to flush this information
 to the next BL image, when LOAD\_IMAGE\_V2 is enabled.
 
+Function : plat\_log\_get\_prefix()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+    Argument : unsigned int
+    Return   : const char *
+
+This function defines the prefix string corresponding to the `log_level` to be
+prepended to all the log output from ARM Trusted Firmware. The `log_level`
+(argument) will correspond to one of the standard log levels defined in
+debug.h. The platform can override the common implementation to define a
+different prefix string for the log output.  The implementation should be
+robust to future changes that increase the number of log levels.
+
 Modifications specific to a Boot Loader stage
 ---------------------------------------------
 
diff --git a/include/common/debug.h b/include/common/debug.h
index 814cf84..3f0f84a 100644
--- a/include/common/debug.h
+++ b/include/common/debug.h
@@ -24,47 +24,62 @@
 #define LOG_LEVEL_VERBOSE		50
 
 #ifndef __ASSEMBLY__
+#include <stdarg.h>
 #include <stdio.h>
 
+/*
+ * Define Log Markers corresponding to each log level which will
+ * be embedded in the format string and is expected by tf_log() to determine
+ * the log level.
+ */
+#define LOG_MARKER_ERROR		"\xa"	/* 10 */
+#define LOG_MARKER_NOTICE		"\x14"	/* 20 */
+#define LOG_MARKER_WARNING		"\x1e"	/* 30 */
+#define LOG_MARKER_INFO			"\x28"	/* 40 */
+#define LOG_MARKER_VERBOSE		"\x32"	/* 50 */
+
 #if LOG_LEVEL >= LOG_LEVEL_NOTICE
-# define NOTICE(...)	tf_printf("NOTICE:  " __VA_ARGS__)
+# define NOTICE(...)	tf_log(LOG_MARKER_NOTICE __VA_ARGS__)
 #else
 # define NOTICE(...)
 #endif
 
 #if LOG_LEVEL >= LOG_LEVEL_ERROR
-# define ERROR(...)	tf_printf("ERROR:   " __VA_ARGS__)
+# define ERROR(...)	tf_log(LOG_MARKER_ERROR __VA_ARGS__)
 #else
 # define ERROR(...)
 #endif
 
 #if LOG_LEVEL >= LOG_LEVEL_WARNING
-# define WARN(...)	tf_printf("WARNING: " __VA_ARGS__)
+# define WARN(...)	tf_log(LOG_MARKER_WARNING __VA_ARGS__)
 #else
 # define WARN(...)
 #endif
 
 #if LOG_LEVEL >= LOG_LEVEL_INFO
-# define INFO(...)	tf_printf("INFO:    " __VA_ARGS__)
+# define INFO(...)	tf_log(LOG_MARKER_INFO __VA_ARGS__)
 #else
 # define INFO(...)
 #endif
 
 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
-# define VERBOSE(...)	tf_printf("VERBOSE: " __VA_ARGS__)
+# define VERBOSE(...)	tf_log(LOG_MARKER_VERBOSE __VA_ARGS__)
 #else
 # define VERBOSE(...)
 #endif
 
-
 void __dead2 do_panic(void);
 #define panic()	do_panic()
 
 /* Function called when stack protection check code detects a corrupted stack */
 void __dead2 __stack_chk_fail(void);
 
+void tf_log(const char *fmt, ...) __printflike(1, 2);
 void tf_printf(const char *fmt, ...) __printflike(1, 2);
 int tf_snprintf(char *s, size_t n, const char *fmt, ...) __printflike(3, 4);
+void tf_vprintf(const char *fmt, va_list args);
+void tf_string_print(const char *str);
+void tf_log_set_max_level(unsigned int log_level);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __DEBUG_H__ */
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index bd721bb..e189f64 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -79,6 +79,7 @@
 int plat_crash_console_flush(void);
 void plat_error_handler(int err) __dead2;
 void plat_panic_handler(void) __dead2;
+const char *plat_log_get_prefix(unsigned int log_level);
 
 /*******************************************************************************
  * Mandatory BL1 functions
diff --git a/plat/common/plat_log_common.c b/plat/common/plat_log_common.c
new file mode 100644
index 0000000..30dcb12
--- /dev/null
+++ b/plat/common/plat_log_common.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <debug.h>
+#include <platform.h>
+
+/* Allow platforms to override the log prefix string */
+#pragma weak plat_log_get_prefix
+
+static const char *prefix_str[] = {
+	"ERROR:   ", "NOTICE:  ", "WARNING: ", "INFO:    ", "VERBOSE: "};
+
+const char *plat_log_get_prefix(unsigned int log_level)
+{
+	if (log_level < LOG_LEVEL_ERROR)
+		log_level = LOG_LEVEL_ERROR;
+	else if (log_level > LOG_LEVEL_VERBOSE)
+		log_level = LOG_LEVEL_VERBOSE;
+
+	return prefix_str[(log_level/10) - 1];
+}