[PATCH] arm64: dts: aspeed: ast2700-evb: Reserve coprocessor, IPC and VBIOS memory

[Billy Tsai]

On the AST2700 EVB, the boot firmware places the SSP and TSP
coprocessor firmware in 0x42c000000-0x42fffffff, the IPC shared memory
in 0x431080000-0x431b2ffff and two VBIOS regions in
0x431bb0000-0x431bcffff, and locks these ranges so that accesses from
the Cortex-A35 are blocked. U-Boot does not add reserved-memory nodes
for these ranges to the DT it passes to Linux, and they are inside the
memory node, so the kernel uses them as ordinary RAM and the EVB fails
to boot once it touches them.

Reserve the regions with no-map so the kernel neither allocates them
nor keeps them in the linear map.

Fixes: e77bb5dc5759 ("arm64: dts: aspeed: Add initial AST27xx SoC device tree")
Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
Assisted-by: LLM
---
 arch/arm64/boot/dts/aspeed/ast2700-evb.dts | 36 ++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/arm64/boot/dts/aspeed/ast2700-evb.dts b/arch/arm64/boot/dts/aspeed/ast2700-evb.dts
index fe8f0b80fb2c..795284253ea5 100644
--- a/arch/arm64/boot/dts/aspeed/ast2700-evb.dts
+++ b/arch/arm64/boot/dts/aspeed/ast2700-evb.dts
@@ -24,6 +24,42 @@ memory@400000000 {
 		device_type = "memory";
 		reg = <0x4 0x00000000 0x0 0x40000000>;
 	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		ssp_memory: ssp-memory@42c000000 {
+			reg = <0x4 0x2c000000 0x0 0x2000000>;
+			no-map;
+		};
+
+		tsp_memory: tsp-memory@42e000000 {
+			reg = <0x4 0x2e000000 0x0 0x2000000>;
+			no-map;
+		};
+
+		ipc_ssp_share: ipc-ssp-share@431080000 {
+			reg = <0x4 0x31080000 0x0 0x800000>;
+			no-map;
+		};
+
+		ipc_bootmcu_share: ipc-bootmcu-share@431880000 {
+			reg = <0x4 0x31880000 0x0 0x2b0000>;
+			no-map;
+		};
+
+		vbios_base0: vbios-base0@431bb0000 {
+			reg = <0x4 0x31bb0000 0x0 0x10000>;
+			no-map;
+		};
+
+		vbios_base1: vbios-base1@431bc0000 {
+			reg = <0x4 0x31bc0000 0x0 0x10000>;
+			no-map;
+		};
+	};
 };
 
 &fmc {

---
base-commit: 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e
change-id: 20261028-ast2700-evb-reserved-memory-e38bfad8619a

Best regards,
-- 
Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>