efi: Tidy up device-tree-size calculation in copy_fdt()
This is a bit confusing at present since it adds 4KB to the pointer, then
rounds it up. It looks like a bug, but is not.
Move the 4KB addition into a separate statement and expand the comment.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index a0fd1a3..d0f2c03 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -148,8 +148,12 @@
fdt_ram_start = ram_start;
}
- /* Give us at least 4kb breathing room */
- fdt_size = ALIGN(fdt_size + 4096, EFI_PAGE_SIZE);
+ /*
+ * Give us at least 4KB of breathing room in case the device tree needs
+ * to be expanded later. Round up to the nearest EFI page boundary.
+ */
+ fdt_size += 4096;
+ fdt_size = ALIGN(fdt_size + EFI_PAGE_SIZE - 1, EFI_PAGE_SIZE);
fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
/* Safe fdt location is at 128MB */