Telenor quirks
--------------
The operator specific firmware running on the Telenor branded
ZyXEL EX5700 includes U-Boot modifications affecting the OpenWrt
installation.
Notable changes to U-Boot include
- environment is stored in RAM and reset to defaults when power
cycled
- dual partition scheme with "nomimal" or "rescue" systems, falling
back to "rescue" unless the OS signals success in 3 attempts
- several runtime additions to the device-tree
Some of these modifications have side effects requiring workarounds
- U-Boot modifies /chosen/bootargs in an unsafe manner, and will crash
unless this node exists
- U-Boot verifies that the selected rootfs UBI volume exists, and
refuses to boot if it doesn't. The chosen "rootfs" volume must contain
a squashfs signature even for tftp or initramfs booting.
- U-Boot parses the "factoryparams" UBI volume, setting the "ethaddr"
variable to the label mac. But "factoryparams" does not always
exist. Instead there is a "RIP" volume containing all the factory
data. Copying the "RIP" volume to "factoryparams" will fix this
Hardware
--------
SOC: MediaTek MT7986
RAM: 1GB DDR4
FLASH: 512MB SPI-NAND (Mikron xxx)
WIFI: Mediatek MT7986 802.11ax 5 GHz
Mediatek MT7916 DBDC 802.11ax 2.4 + 6 GHz
ETH: MediaTek MT7531 Switch + SoC
3 x builtin 1G phy (lan1, lan2, lan3)
2 x MaxLinear GPY211C 2.5 N-Base-T phy (lan4, wan)
USB: 1 x USB 3.2 Enhanced SuperSpeed port
UART: 3V3 115200 8N1 (Pinout: GND KEY RX TX VCC)
Installation
------------
1. Download the OpenWrt initramfs image. Copy the image to a TFTP server
reachable at 192.168.1.2/24. Rename the image to C0A80101.img.
2. Connect the TFTP server to lan1, lan2 or lan3. Connect to the serial
console, Interrupt the autoboot process by pressing ESC when prompted.
3. Download and boot the OpenWrt initramfs image.
$ env set uboot_bootcount 0
$ env set firmware nominal
$ tftpboot
$ bootm
4. Wait for OpenWrt to boot. Transfer the sysupgrade image to the device
using scp and install using sysupgrade.
$ sysupgrade -n <path-to-sysupgrade.bin>
Missing features
----------------
- The "lan1", "lan2" and "lan3" port LEDs are driven by the switch but
OpenWrt does not correctly configure the output.
- The "lan4" and "wan" port LEDs are driven by the GPH211C phys and
not configured by OpenWrt.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
