blkmap: pass information on ISO image to the OS

The EFI HTTP boot puts the ISO installer image at some location in
memory. Information about this image has to be passed on to the OS
kernel, which is done by adding a persistent memory(pmem) node to the
devicetree(DT) that is passed to the OS. The OS kernel then gets
information about the presence of this ISO image and proceeds with the
installation.

In U-Boot, this ISO image gets mounted as a memory mapped blkmap
device slice, with the 'preserve' attribute. Add a helper function
which iterates through all such slices, and invokes a callback. The
callback adds the pmem node to the DT and removes the corresponding
memory region from the EFI memory map. Invoke this helper function as
part of the DT fixup which happens before booting the OS.

Signed-off-by: Sughosh Ganu <[email protected]>
Reviewed-by: Tobias Waldekranz <[email protected]>
Signed-off-by: Ilias Apalodimas <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index 9d1598b1a93..8f718ad29f6 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -11,6 +11,7 @@
 #include <command.h>
 #include <fdt_support.h>
 #include <fdtdec.h>
+#include <efi.h>
 #include <env.h>
 #include <errno.h>
 #include <image.h>
@@ -649,6 +650,12 @@ int image_setup_libfdt(struct bootm_headers *images, void *blob, bool lmb)
 	if (!ft_verify_fdt(blob))
 		goto err;
 
+	if (CONFIG_IS_ENABLED(BLKMAP) && CONFIG_IS_ENABLED(EFI_LOADER)) {
+		fdt_ret = fdt_efi_pmem_setup(blob);
+		if (fdt_ret)
+			goto err;
+	}
+
 	/* after here we are using a livetree */
 	if (!of_live_active() && CONFIG_IS_ENABLED(EVENT)) {
 		struct event_ft_fixup fixup;