On 2/1/25 04:42, Masahiro Yamada wrote:
On Sat, Feb 1, 2025 at 7:25 AM Rob Herring <robh@xxxxxxxxxx> wrote:
On Tue, Jan 14, 2025 at 12:15 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
The default image linux.bin does not contain any DTB, but a separate
system.dtb is compiled.
Michal Simek clearly explained "system.dtb is really old dtb more for
demonstration purpose and nothing else and likely it is not working on
any existing board." [1]
The system.dts is not necessary even for demonstration purposes. There
is no need to compile out-of-tree *.dts under arch/microblaze/boot/dts/
unless it is embedded into the kernel. Users can directly use dtc.
[1]: https://lore.kernel.org/all/d2bdfbfd-3721-407f-991e-566d48392add@xxxxxxx/
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
arch/microblaze/boot/dts/Makefile | 3 +-
arch/microblaze/boot/dts/system.dts | 353 ----------------------------
2 files changed, 1 insertion(+), 355 deletions(-)
delete mode 100644 arch/microblaze/boot/dts/system.dts
diff --git a/arch/microblaze/boot/dts/Makefile b/arch/microblaze/boot/dts/Makefile
index 932dc7550a1b..fa0a6c0854ca 100644
--- a/arch/microblaze/boot/dts/Makefile
+++ b/arch/microblaze/boot/dts/Makefile
@@ -1,8 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
#
-dtb-y := system.dtb
-
ifneq ($(DTB),)
obj-y += linked_dtb.o
@@ -11,6 +9,7 @@ $(obj)/linked_dtb.o: $(obj)/system.dtb
# Generate system.dtb from $(DTB).dtb
ifneq ($(DTB),system)
Can't this be dropped as setting DTB=system.dtb should work if there's
not an in-tree system.dts anymore.
I believe this ifneq is necessary, just in case
a user adds system.dtb to arch/microblaze/boot/dts/.
'system.dtb' is a special name because
arch/microblaze/boot/dts/linked_dtb.S wraps it.
So, $(DTB) is copied to system.dtb, and then
it is wrapped by linked_dtb.S.
If $(DTB) is already 'system',
we cannot copy system.dtb to itself.
See the definition of cmd_copy in scripts/Makefile.lib
cmd_copy = cat $< > $@
"cat system.dtb > system.dtb"
would create an empty system.dtb
I have played with this and pretty much this patch is blocking
simpleImage.system build target.
I have no issue with patches 1-3 and I would keep system.dts as empty and keep
it in the tree because users (including me) just rewrite system.dts with proper
DTS and call make simpleImage.system.
Thanks,
Michal
--
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP/Versal ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal/Versal NET SoCs
TF-A maintainer - Xilinx ZynqMP/Versal/Versal NET SoCs
