Some boards set fdt_high to -1 which means that the FDT is not relocated
in boot_relocate_fdt().
A comment in that function says that we assume there is space after the
existing fdt to use for padding, with the padding size set to
CONFIG_SYS_FDT_PAD
However, there is no guarantee that this space is available. If using
the control FDT, then global_data is immediately above it, so expanding
the FDT and adding FDT properties will cause U-Boot to fail.
Add a new Kconfig option to provide the required space, enabling it by
default.
Signed-off-by: Simon Glass <s...@chromium.org>
---
common/board_f.c | 6 ++++--
dts/Kconfig | 11 +++++++++++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/common/board_f.c b/common/board_f.c
index 8baaa2341a3..ed30aeeab23 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -553,8 +553,10 @@ static int reserve_fdt(void)
* section, then it will be relocated with other data.
*/
if (gd->fdt_blob) {
- gd->boardf->fdt_size =
- ALIGN(fdt_totalsize(gd->fdt_blob), 32);
+ int size = fdt_totalsize(gd->fdt_blob);
+
+ gd->boardf->fdt_size = ALIGN(size + CONFIG_OF_EXPAND,
+ 32);
gd->start_addr_sp = reserve_stack_aligned(
gd->boardf->fdt_size);
diff --git a/dts/Kconfig b/dts/Kconfig
index 41a758e83a6..360611edd01 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -219,6 +219,17 @@ config OF_OMIT_DTB
This is used for boards which normally provide a devicetree via a
runtime mechanism (such as OF_BOARD), to avoid confusion.
+config OF_EXPAND
+ hex # "Amount to allow the control FDT to expand"
+ default SYS_FDT_PAD if OF_LIBFDT
+ default 0
+ help
+ Some boards make use of the control FDT to boot an OS, thus when
+ image_setup_libfdt() adds extra things to the end of the FDT, there
+ needs to be enough space.
+
+ Set this to the number of bytes of extra space required for the FDT.
+
config DEFAULT_DEVICE_TREE
string "Default Device Tree for DT control"
depends on OF_CONTROL
--
2.34.1
