ramips: add support for read/write uboot env to Asus RX-AX53U

Add support for read/writing uboot env by renaming the second partition
to its stock label "nvram" and remove the deemed unnecessary
"read-only". Split the first partition "u-boot" in two, in order
to allow `fw_setenv` safe write-access to the uboot environment
variables.

This implements hauke's request from [1].
Based on the patch provided by Shiji Yang.

[1] https://github.com/openwrt/openwrt/pull/10400#discussion_r945153224

Co-Authored-By: Shiji Yang <yangshiji66@qq.com>
Signed-off-by: Felix Baumann <felix.bau@gmx.de>
[ improve commit title and description, fix some whitespace problem ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/target/linux/ramips/dts/mt7621_asus_rt-ax53u.dts b/target/linux/ramips/dts/mt7621_asus_rt-ax53u.dts
index aec8a0494d12433927fd72577cf32e02bb6aa417..6a5cb0d7193e7fcc9a906a2cd59da362b945062d 100644 (file)
--- a/target/linux/ramips/dts/mt7621_asus_rt-ax53u.dts
+++ b/target/linux/ramips/dts/mt7621_asus_rt-ax53u.dts
@@ -60,12 +60,21 @@
 
                partition@0 {
                        label = "u-boot";
-                       reg = <0x0 0xe0000>;
+                       reg = <0x0 0x80000>;
                        read-only;
                };
 
-               partition@e0000 {
+               /*
+                * u-boot gets split here while keeping u-boot read-only,
+                * which allows safe usage of fw_setenv
+                */
+               partition@80000 {
                        label = "u-boot-env";
+                       reg = <0x80000 0x60000>;
+               };
+
+               partition@e0000 {
+                       label = "nvram";
                        reg = <0xe0000 0x100000>;
                        read-only;
                };