Issue #647: Update Radxa dual 2.5G router HAT.

Author: geerlingguy

_hats/radxa-dual-2.5g-router.md

@@ -8,11 +8,11 @@ github_issue: "https://github.com/geerlingguy/raspberry-pi-pcie-devices/issues/6
 link: "https://docs.radxa.com/en/accessories/dual-2.5-router-hat"
 videos: []
 ---
-This HAT includes two 2.5 Gbps Ethernet ports (Realtek 8125BG), an M.2 M-key NVMe slot (2230, 2242, 2260, 2280), and a 12V power input.
+This HAT includes two 2.5 Gbps Ethernet ports (Realtek 8125BG), an M.2 M-key NVMe slot (2230, 2242, 2260, 2280), an additional PCIe FPC connector (to stack an additional PCIe HAT on top) and a 12V power input.
 
-The interfaces are adapted through an ASM2806 PCIe Gen 3 switch, with 2 uplinks (the Pi 5 can only use 1), and 4 downlinks—the 4th is exposed as a Pi 5 style PCIe FPC header, so you can daisy-chain other PCIe boards on top of this one!
+The interfaces are adapted through an ASM2806 PCIe Gen 3 switch, with 2 uplinks (the Pi 5 can only use 1), and 4 downlinks.
 
-It has a 40 pin GPIO plug, which supplies power to the Pi, and it is not pass-through type, so you would not be able to mount another HAT on top of this board.
+It has a 40 pin GPIO plug, which supplies power to the Pi, and it is not pass-through type, so you would not be able to mount another HAT requiring GPIO on top of this board.
 
 **You must manually enable the external PCIe connector** to get this HAT to work on the Pi 5. Also, if you want Gen 3.0 speeds, also add that setting in `/boot/firmware/config.txt` and reboot:
 
@@ -21,4 +21,10 @@ dtparam=pciex1
 dtparam=pciex1_gen=3
 ```
 
+Because this HAT is not 'HAT+' compatible, if you want to [boot from PCIe](https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#boot-from-pcie), you must also edit the Raspberry Pi EEPROM (`sudo rpi-eeprom-config -e`) and add the following line:
+
+```
+PCIE_PROBE=1
+```
+
 I am currently testing the board and will update this page with more information later.