Ahmed Naseef
ee2e25f009
The Airtel AirFiber AAP4221ZY is an ISP-provided router that is part
of the ISP's Fixed Wireless Access (FWA) solution. The FWA system
consists of two units: an outdoor 5G unit and this indoor Wi-Fi router
connected via a PoE ethernet link. This commit adds support for the
indoor unit.
The OEM appears to be Zyxel with model number EX3310-T0, although this
is not printed on any label and only found in the vendor firmware DTS,
bootlog, and other internal references.
Hardware
--------
SOC: MediaTek MT7981B
CPU: 2 core Cortex-A53 (1300MHz)
RAM: 512MB DDR3
FLASH: 512MB SPI-NAND (Micron, 4096 page, 256KiB block)
WIFI: MediaTek MT7976 802.11ax 2x2 2.4GHz + 5GHz
ETH: Airoha AN8855 GbE Switch (2x LAN) + MT7981 internal GbE PHY (WAN)
POE: WAN port provides PoE to the outdoor unit (GPIO 10)
UART: 3V3 115200 8N1
Bootloader
----------
The device uses BL2 -> U-Boot -> Zyxel zloader chain. U-Boot has a
hardcoded command to always launch zloader (similar to the Zyxel
EX5601-T0, see commit 1c05388ab0). zloader is the Zyxel secondary
bootloader which handles dual-boot (ubi/ubi2 A/B scheme), firmware
verification, and PoE port enablement.
zloader requires a UBI volume named "zyfwinfo" containing a 256-byte
metadata structure with a "ZYXE" magic header and a valid checksum.
Without this volume, zloader refuses to boot the firmware. The
zyfwinfo structure also contains a sequence number (range 0-9999,
wraps around) used to select which firmware bank to boot - the bank
with the higher sequence number wins. This OpenWrt image sets it to
5555 to always win over stock firmware starting at 0.
During sysupgrade, platform.sh refreshes the zyfwinfo volume before
writing kernel and rootfs to UBI, as rootfs_data is sized to fill the
remaining space.
Note that OpenWrt can only be flashed to ubi (mtd6). The zloader
appends rootubi=ubi or rootubi=ubi2 to the kernel bootargs based on
which partition it selects, but OpenWrt cannot understand this
parameter, so the firmware must always reside on the first bank (ubi).
UART access
-----------
Serial console output is restricted by the U-Boot environment variable
EngDebugFlag which is 0x00 by default. Users need to first obtain root
access on the vendor firmware and run:
fw_setenv EngDebugFlag 0x01
Then reboot. Connect UART and press Enter to enter the zloader shell
(ZHAL> prompt). Use the ATGU command to switch to the U-Boot shell.
Note: ATGU must be entered twice to get the MT7981> prompt:
ZHAL> ATGU
[zloader reloads]
ZHAL> ATGU
MT7981>
Installation
------------
1. Enable UART access as described above.
2. Enter U-Boot shell (ATGU twice from ZHAL> prompt).
3. Load the initramfs image via TFTP:
MT7981> setenv ipaddr 192.168.1.1
MT7981> setenv serverip 192.168.1.2
MT7981> tftpboot 0x46000000 openwrt-mediatek-filogic-airtel_aap4221zy-initramfs-kernel.bin
MT7981> bootm 0x46000000
4. Once OpenWrt boots from initramfs, transfer and flash the
sysupgrade image:
sysupgrade -n /tmp/openwrt-mediatek-filogic-airtel_aap4221zy-squashfs-sysupgrade.bin
5. The device will reboot and zloader will boot OpenWrt from flash.
Signed-off-by: Ahmed Naseef <naseefkm@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/22809
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
OpenWrt Project is a Linux operating system targeting embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. For developers, OpenWrt is the framework to build an application without having to build a complete firmware around it; for users this means the ability for full customization, to use the device in ways never envisioned.
Sunshine!
Download
Built firmware images are available for many architectures and come with a package selection to be used as WiFi home router. To quickly find a factory image usable to migrate from a vendor stock firmware to OpenWrt, try the Firmware Selector.
If your device is supported, please follow the Info link to see install instructions or consult the support resources listed below.
An advanced user may require additional or specific package. (Toolchain, SDK, ...) For everything else than simple firmware download, try the wiki download page:
Development
To build your own firmware you need a GNU/Linux, BSD or macOS system (case sensitive filesystem required). Cygwin is unsupported because of the lack of a case sensitive file system.
Requirements
You need the following tools to compile OpenWrt, the package names vary between distributions. A complete list with distribution specific packages is found in the Build System Setup documentation.
binutils bzip2 diff find flex gawk gcc-6+ getopt grep install libc-dev libz-dev
make4.1+ perl python3.8+ rsync subversion unzip which
Quickstart
-
Run
./scripts/feeds update -ato obtain all the latest package definitions defined in feeds.conf / feeds.conf.default -
Run
./scripts/feeds install -ato install symlinks for all obtained packages into package/feeds/ -
Run
make menuconfigto select your preferred configuration for the toolchain, target system & firmware packages. -
Run
maketo build your firmware. This will download all sources, build the cross-compile toolchain and then cross-compile the GNU/Linux kernel & all chosen applications for your target system.
Related Repositories
The main repository uses multiple sub-repositories to manage packages of
different categories. All packages are installed via the OpenWrt package
manager called opkg. If you're looking to develop the web interface or port
packages to OpenWrt, please find the fitting repository below.
-
LuCI Web Interface: Modern and modular interface to control the device via a web browser.
-
OpenWrt Packages: Community repository of ported packages.
-
OpenWrt Routing: Packages specifically focused on (mesh) routing.
-
OpenWrt Video: Packages specifically focused on display servers and clients (Xorg and Wayland).
Support Information
For a list of supported devices see the OpenWrt Hardware Database
Documentation
Support Community
- Forum: For usage, projects, discussions and hardware advise.
- Support Chat: Channel
#openwrton oftc.net.
Developer Community
- Bug Reports: Report bugs in OpenWrt
- Dev Mailing List: Send patches
- Dev Chat: Channel
#openwrt-develon oftc.net.
License
OpenWrt is licensed under GPL-2.0