fit: Introduce methods for applying overlays on fit-load

Introduce an overlay based method for constructing a base DT blob
to pass to the kernel.

It is based on a specific method now to get the FDT from a FIT image
named boot_get_fdt_fit().

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/image.h b/include/image.h
index 339f79c6dc..af98ed9f25 100644
--- a/include/image.h
+++ b/include/image.h
@@ -594,6 +594,31 @@ int boot_get_setup_fit(bootm_headers_t *images, uint8_t arch,
 		       ulong *setup_start, ulong *setup_len);
 
 /**
+ * boot_get_fdt_fit() - load a DTB from a FIT file (applying overlays)
+ *
+ * This deals with all aspects of loading an DTB from a FIT.
+ * The correct base image based on configuration will be selected, and
+ * then any overlays specified will be applied (as present in fit_uname_configp).
+ *
+ * @param images	Boot images structure
+ * @param addr		Address of FIT in memory
+ * @param fit_unamep	On entry this is the requested image name
+ *			(e.g. "kernel@1") or NULL to use the default. On exit
+ *			points to the selected image name
+ * @param fit_uname_configp	On entry this is the requested configuration
+ *			name (e.g. "conf@1") or NULL to use the default. On
+ *			exit points to the selected configuration name.
+ * @param arch		Expected architecture (IH_ARCH_...)
+ * @param datap		Returns address of loaded image
+ * @param lenp		Returns length of loaded image
+ *
+ * @return node offset of base image, or -ve error code on error
+ */
+int boot_get_fdt_fit(bootm_headers_t *images, ulong addr,
+		   const char **fit_unamep, const char **fit_uname_configp,
+		   int arch, ulong *datap, ulong *lenp);
+
+/**
  * fit_image_load() - load an image from a FIT
  *
  * This deals with all aspects of loading an image from a FIT, including