On 4/13/20 10:03 AM, Michal Simek wrote:
From: Ashok Reddy Soma ashok.reddy.soma@xilinx.com
FDT memory is aligned by 4KB. This is hardcoded in common/board_f.c. Add Kconfig option, assign default value of 0x1000 and enable option to change this value.
Please, describe why this patch is needed.
Signed-off-by: Ashok Reddy Soma ashok.reddy.soma@xilinx.com Signed-off-by: Michal Simek michal.simek@xilinx.com
common/board_f.c | 3 ++- dts/Kconfig | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/common/board_f.c b/common/board_f.c index 82a164752aa3..928874e03555 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -546,7 +546,8 @@ static int reserve_fdt(void) * will be relocated with other data. */ if (gd->fdt_blob) {
gd->fdt_size = ALIGN(fdt_totalsize(gd->fdt_blob) + 0x1000, 32);
gd->fdt_size = ALIGN(fdt_totalsize(gd->fdt_blob) +CONFIG_FDT_MEM_ALIGN_SIZE, 32);gd->start_addr_sp -= gd->fdt_size; gd->new_fdt = map_sysmem(gd->start_addr_sp, gd->fdt_size);
This change does not relate to the commit message. You are not adjusting the alignment of the device tree location. You are adjusting the size of the memory available for the device tree.
reserve_fdt() is called after reserve_global_data() where we have: gd->start_addr_sp -= sizeof(gd_t).
A typical debug output from reserve_global_data() is: Reserving 544 Bytes for Global Data at: bf740d98
So in this case the device tree will have an alignment of 8 no matter what power of 2 (>= 8) you choose for CONFIG_FDT_MEM_ALIGN_SIZE.
What about other places where we allocate memory for device trees like copy_fdt() in cmd/bootefi.?
diff --git a/dts/Kconfig b/dts/Kconfig index 046a54a17366..696c0b71afaf 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -121,6 +121,13 @@ config DEFAULT_DEVICE_TREE It can be overridden from the command line: $ make DEVICE_TREE=<device-tree-name>
+config FDT_MEM_ALIGN_SIZE
- hex "FDT memory alignment size"
- default 0x1000
- help
This option is used to set the default alignment when reserving memory
%s/is used to set the default alignment/sets the alignment/
Please, mention if this value should be a power of 2.
Best regards
Heinrich
for fdt.config OF_LIST string "List of device tree files to include for DT control" depends on SPL_LOAD_FIT || MULTI_DTB_FIT