image: introduce genimg_get_kernel_addr()

Kernel address is normally stored as a string argument of bootm or bootz.
This function is taken out from boot_get_kernel() of bootm.c, which can be
reused by others.

Signed-off-by: Bryan Wu <pengw@nvidia.com>
[trini: Fix warnings with CONFIG_FIT]
Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/common/image.c b/common/image.c
index 11b3cf5..a2999c0 100644
--- a/common/image.c
+++ b/common/image.c
@@ -643,6 +643,49 @@
 
 #ifndef USE_HOSTCC
 /**
+ * genimg_get_kernel_addr - get the real kernel address
+ * @img_addr: a string might contain real image address
+ *
+ * genimg_get_kernel_addr() get the real kernel start address from a string
+ * which is normally the first argv of bootm/bootz
+ *
+ * returns:
+ *     kernel start address
+ */
+ulong genimg_get_kernel_addr(char * const img_addr)
+{
+#if defined(CONFIG_FIT)
+	const char	*fit_uname_config = NULL;
+	const char	*fit_uname_kernel = NULL;
+#endif
+
+	ulong kernel_addr;
+
+	/* find out kernel image address */
+	if (!img_addr) {
+		kernel_addr = load_addr;
+		debug("*  kernel: default image load address = 0x%08lx\n",
+		      load_addr);
+#if defined(CONFIG_FIT)
+	} else if (fit_parse_conf(img_addr, load_addr, &kernel_addr,
+				  &fit_uname_config)) {
+		debug("*  kernel: config '%s' from image at 0x%08lx\n",
+		      fit_uname_config, kernel_addr);
+	} else if (fit_parse_subimage(img_addr, load_addr, &kernel_addr,
+				     &fit_uname_kernel)) {
+		debug("*  kernel: subimage '%s' from image at 0x%08lx\n",
+		      fit_uname_kernel, kernel_addr);
+#endif
+	} else {
+		kernel_addr = simple_strtoul(img_addr, NULL, 16);
+		debug("*  kernel: cmdline image address = 0x%08lx\n",
+		      kernel_addr);
+	}
+
+	return kernel_addr;
+}
+
+/**
  * genimg_get_format - get image format type
  * @img_addr: image start address
  *
diff --git a/include/image.h b/include/image.h
index 3e8f78d..ca2fe86 100644
--- a/include/image.h
+++ b/include/image.h
@@ -424,6 +424,7 @@
 #define IMAGE_FORMAT_FIT	0x02	/* new, libfdt based format */
 #define IMAGE_FORMAT_ANDROID	0x03	/* Android boot image */
 
+ulong genimg_get_kernel_addr(char * const img_addr);
 int genimg_get_format(const void *img_addr);
 int genimg_has_config(bootm_headers_t *images);
 ulong genimg_get_image(ulong img_addr);