[PATCH v2 1/2] arm: dts: aspeed: add an alt 128M flash layout

[Marc Olberding]

Add a 128M layout for the BMC flash chip we didn't boot from. Including
this allows the user to write to each partition on the alternate spi
chip. This dtsi follows the existing standard of using the same layout
as non alt version and prepending `alt` to each partition's name.

Testing: Include this in msx4 and cat size, offsets and name
```
for devdir in /sys/class/mtd/mtd*; do
>     [[ -d $devdir && -r $devdir/name ]] || continue
>     name=$(<"$devdir/name")
>     [[ $name == alt* ]] || continue
>
>     size=$(<"$devdir/size")
>     offset=0
>     [[ -r $devdir/offset ]] && offset=$(<"$devdir/offset")
>
>     dev=$(basename "$devdir")
>     printf "%s name=%s offset=0x%X size=0x%X\n" "$dev" "$name" \
>        "$offset" "$size"
> done
mtd10 name=alt-rofs offset=0xA00000 size=0x5600000
mtd11 name=alt-rwfs offset=0x6000000 size=0x2000000
mtd7 name=alt-u-boot offset=0x0 size=0xE0000
mtd8 name=alt-u-boot-env offset=0xE0000 size=0x20000
mtd9 name=alt-kernel offset=0x100000 size=0x900000
```

Signed-off-by: Marc Olberding <molberding at nvidia.com>
---
 .../dts/aspeed/openbmc-flash-layout-128-alt.dtsi   | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi b/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..08ce2eab472c3da4aa3d841adb0eb1c971e6a25a
--- /dev/null
+++ b/arch/arm/boot/dts/aspeed/openbmc-flash-layout-128-alt.dtsi
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+partitions {
+	compatible = "fixed-partitions";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	u-boot at 0 {
+		reg = <0x0 0xe0000>; // 896KB
+		label = "alt-u-boot";
+	};
+
+	u-boot-env at e0000 {
+		reg = <0xe0000 0x20000>; // 128KB
+		label = "alt-u-boot-env";
+	};
+
+	kernel at 100000 {
+		reg = <0x100000 0x900000>; // 9MB
+		label = "alt-kernel";
+	};
+
+	rofs at a00000 {
+		reg = <0xa00000 0x5600000>; // 86MB
+		label = "alt-rofs";
+	};
+
+	rwfs at 6000000 {
+		reg = <0x6000000 0x2000000>; // 32MB
+		label = "alt-rwfs";
+	};
+};

-- 
2.34.1