mt7981-usb-sfp-patcher

Patch existing OpenWRT firmware to use the USB3 on the MT7981 to connect to 2500Base-X SFP module. Support both OpenWrt U-Boot layout and custom U-Boot layout

Tested Device

• CMCC RAX3000M

Tested OpenWRT Versions

• OpenWRT 23.05.4
• ImmortalWrt 23.05-SNAPSHOT (r27946-868b12b200)

How to use

Presquites

• Install U-Boot Tools and Device Tree Compiler

Debian / Ubuntu: sudo apt install u-boot-tools device-tree-compiler

Arch Linux: sudo pacman -S uboot-tools dtc

Homebrew: brew install u-boot-tools dtc

• Install python3 with hashlib, zlib

Steps

1. Clone this repository

git clone https://github.com/cyyself/mt7981-usb-sfp-patcher.git
cd mt7981-usb-sfp-patcher

For OpenWRT Origin version

1. Patch the firmware

wget https://downloads.openwrt.org/releases/23.05.4/targets/mediatek/filogic/openwrt-23.05.4-mediatek-filogic-cmcc_rax3000m-squashfs-sysupgrade.itb
python3 patch_itb.py openwrt-23.05.4-mediatek-filogic-cmcc_rax3000m-squashfs-sysupgrade.itb patched.itb

2. (Optional) Verify the patched dts

diff build/orig.dts build/patched.dts

8c8
<       model = "CMCC RAX3000M";
---
>       model = "CMCC RAX3000M with USB3SFP";
549,551c549,550
<                       phy-mode = "gmii";
<                       phy-handle = <0x1f>;
<                       phandle = <0x39>;
---
>                       phy-mode = "2500base-x";
>                       managed = "in-band-status";
686c685
<               phys = <0x21 0x03 0x0f 0x04>;
---
>               phys = <0x21 0x03>;
689a689
>               mediatek,u3p-dis-msk = <0x01>;
931c931
< };
---
> };
\ No newline at end of file

3. Use sysupgrade -F or LuCI to flash the patched firmware

It's normal to get a warning "Image check failed", but "Force upgrade" should work.

For ImmortalWrt with custom U-Boot layout

1. Dump kernel raw image from device

ssh root@192.168.1.1 dd if=/dev/ubi0_0 of=/tmp/kernel
scp -O root@192.168.1.1:/tmp/kernel ./kernel

2. Patch the kernel

python3 patch_itb.py ./kernel ./kernel-patched

3. Flash the patched kernel

scp -O ./kernel-patched root@192.168.1.1:/tmp/
ssh root@192.168.1.1 ubiupdatevol /dev/ubi0_0 /tmp/kernel-patched

Now reboot your device.

Limitation

Since there are only 2 Ethernet MACs in the MT7981 SoC, If your router uses both of them for WAN and LAN (e.g. CMCC RAX300M), the original eth1 (typically WAN port) will be disabled.

For OpenWRT Developers / Advanced Users

Please see this dts patch.

Notice

A patch to enable the flow control of the SFP module is under review.