SPL: Add XIP booting support

Enable support for XIP (execute in place) of U-Boot or kernel image. There is
no need to copy image from flash to ram if flash supports execute in place.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Reviewed-by: Alexandru Gagniuc <alex.g@adaptrum.com>
diff --git a/common/spl/spl_xip.c b/common/spl/spl_xip.c
new file mode 100644
index 0000000..18c7d11
--- /dev/null
+++ b/common/spl/spl_xip.c
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2017 Vikas Manocha <vikas.manocha@st.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spl.h>
+
+static int spl_xip(struct spl_image_info *spl_image,
+		   struct spl_boot_device *bootdev)
+{
+#ifdef CONFIG_SPL_OS_BOOT
+	if (!spl_start_uboot()) {
+		spl_image->arg = (void *)CONFIG_SYS_FDT_BASE;
+		spl_image->name = "Linux";
+		spl_image->os = IH_OS_LINUX;
+		spl_image->load_addr = CONFIG_SYS_LOAD_ADDR;
+		spl_image->entry_point = CONFIG_SYS_LOAD_ADDR;
+		debug("spl: payload xipImage, load addr: 0x%lx\n",
+		      spl_image->load_addr);
+		return 0;
+	}
+#endif
+	return(spl_parse_image_header(spl_image, (const struct image_header *)
+	       CONFIG_SYS_UBOOT_BASE));
+}
+SPL_LOAD_IMAGE_METHOD("XIP", 0, BOOT_DEVICE_XIP, spl_xip);