[U-Boot] [PATCH] efi_loader: Reserve 2 additional pages for fdt

[Alexander Graf]

We mark the device tree as reserved today, spanning exactly the amount
of space it needs. If some other piece of code (like grub2) comes in and
wants to modify the device tree to for example add a kernel command line
though, it might assume that it has some space to do so.

So let's just reserve 2 additional pages for the device tree to play nicely.

Signed-off-by: Alexander Graf <agraf at suse.de>
---
 cmd/bootefi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index de17e49..faa6978 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -119,6 +119,8 @@ static unsigned long do_bootefi_exec(void *efi)
 		fdt_end = ((ulong)working_fdt) + fdt_totalsize(working_fdt);
 		fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
 		fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
+		/* Give a bootloader the chance to modify the device tree */
+		fdt_pages += 2;
 		efi_add_memory_map(fdt_start, fdt_pages,
 				   EFI_BOOT_SERVICES_DATA, true);
 
-- 
1.8.5.6