ath79: support Ruckus ZoneFlex 7321

ath79: support Ruckus ZoneFlex 7321

Ruckus ZoneFlex 7321 is a dual-band, single radio 802.11n 2x2 MIMO enterprise
access point. It is very similar to its bigger brother, ZoneFlex 7372.

Hardware highligts:
- CPU: Atheros AR9342 SoC at 533 MHz
- RAM: 64MB DDR2
- Flash: 32MB SPI-NOR
- Wi-Fi: AR9342 built-in dual-band 2x2 MIMO radio
- Ethernet: single Gigabit Ethernet port through AR8035 gigabit PHY
- PoE: input through Gigabit port
- Standalone 12V/1A power input
- USB: optional single USB 2.0 host port on the 7321-U variant.

Serial console: 115200-8-N-1 on internal H1 header.
Pinout:

H1 ----------
   |1|x3|4|5|
   ----------

Pin 1 is near the "H1" marking.
1 - RX
x - no pin
3 - VCC (3.3V)
4 - GND
5 - TX

JTAG: Connector H5, unpopulated, similar to MIPS eJTAG, standard,
but without the key in pin 12 and not every pin routed:

------- H5
|1 |2 |
-------
|3 |4 |
-------
|5 |6 |
-------
|7 |8 |
-------
|9 |10|
-------
|11|12|
-------
|13|14|
-------

3 - TDI
5 - TDO
7 - TMS
9 - TCK
2,4,6,8,10 - GND
14 - Vref
1,11,12,13 - Not connected

Installation:
There are two methods of installation:
- Using serial console [1] - requires some disassembly, 3.3V USB-Serial
  adapter, TFTP server,  and removing a single T10 screw,
  but with much less manual steps, and is generally recommended, being
  safer.
- Using stock firmware root shell exploit, SSH and TFTP [2]. Does not
  work on some rare versions of stock firmware. A more involved, and
  requires installing `mkenvimage` from u-boot-tools package if you
  choose to rebuild your own environment, but can be used without
  disassembly or removal from installation point, if you have the
  credentials.
  If for some reason, size of your sysupgrade image exceeds 13312kB,
  proceed with method [1]. For official images this is not likely to
  happen ever.

[1] Using serial console:
0. Connect serial console to H1 header. Ensure the serial converter
   does not back-power the board, otherwise it will fail to boot.

1. Power-on the board. Then quickly connect serial converter to PC and
   hit Ctrl+C in the terminal to break boot sequence. If you're lucky,
   you'll enter U-boot shell. Then skip to point 3.
   Connection parameters are 115200-8-N-1.

2. Allow the board to boot.  Press the reset button, so the board
   reboots into U-boot again and go back to point 1.

3. Set the "bootcmd" variable to disable the dual-boot feature of the
   system and ensure that uImage is loaded. This is critical step, and
   needs to be done only on initial installation.

   > setenv bootcmd "bootm 0x9f040000"
   > saveenv

4. Boot the OpenWrt initramfs using TFTP. Replace IP addresses as needed:

   > setenv serverip 192.168.1.2
   > setenv ipaddr 192.168.1.1
   > tftpboot 0x81000000 openwrt-ath79-generic-ruckus_zf7321-initramfs-kernel.bin
   > bootm 0x81000000

5. Optional, but highly recommended: back up contents of "firmware" partition:

   $ ssh root@192.168.1.1 cat /dev/mtd1 > ruckus_zf7321_fw1_backup.bin
   $ ssh root@192.168.1.1 cat /dev/mtd5 > ruckus_zf7321_fw2_backup.bin

6. Copy over sysupgrade image, and perform actual installation. OpenWrt
   shall boot from flash afterwards:

   $ ssh root@192.168.1.1
   # sysupgrade -n openwrt-ath79-generic-ruckus_zf7321-squashfs-sysupgrade.bin

[2] Using stock root shell:
0. Reset the device to factory defaullts. Power-on the device and after
   it boots, hold the reset button near Ethernet connectors for 5
   seconds.

1. Connect the device to the network. It will acquire address over DHCP,
   so either find its address using list of DHCP leases by looking for
   label MAC address, or try finding it by scanning for SSH port:

   $ nmap 10.42.0.0/24 -p22

   From now on, we assume your computer has address 10.42.0.1 and the device
   has address 10.42.0.254.

2. Set up a TFTP server on your computer. We assume that TFTP server
   root is at /srv/tftp.

3. Obtain root shell. Connect to the device over SSH. The SSHD ond the
   frmware is pretty ancient and requires enabling HMAC-MD5.

   $ ssh 10.42.0.254 \
   -o UserKnownHostsFile=/dev/null \
   -o StrictHostKeyCheking=no \
   -o MACs=hmac-md5

   Login. User is "super", password is "sp-admin".
   Now execute a hidden command:

   Ruckus

   It is case-sensitive. Copy and paste the following string,
   including quotes. There will be no output on the console for that.

   ";/bin/sh;"

   Hit "enter". The AP will respond with:

   grrrr
   OK

   Now execute another hidden command:

   !v54!

   At "What's your chow?" prompt just hit "enter".
   Congratulations, you should now be dropped to Busybox shell with root
   permissions.

4. Optional, but highly recommended: backup the flash contents before
   installation. At your PC ensure the device can write the firmware
   over TFTP:

   $ sudo touch /srv/tftp/ruckus_zf7321_firmware{1,2}.bin
   $ sudo chmod 666 /srv/tftp/ruckus_zf7321_firmware{1,2}.bin

   Locate partitions for primary and secondary firmware image.
   NEVER blindly copy over MTD nodes, because MTD indices change
   depending on the currently active firmware, and all partitions are
   writable!

   # grep rcks_wlan /proc/mtd

   Copy over both images using TFTP, this will be useful in case you'd
   like to return to stock FW in future. Make sure to backup both, as
   OpenWrt uses bot firmwre partitions for storage!

   # tftp -l /dev/<rcks_wlan.main_mtd> -r ruckus_zf7321_firmware1.bin -p 10.42.0.1
   # tftp -l /dev/<rcks_wlan.bkup_mtd> -r ruckus_zf7321_firmware2.bin -p 10.42.0.1

   When the command finishes, copy over the dump to a safe place for
   storage.

   $ cp /srv/tftp/ruckus_zf7321_firmware{1,2}.bin ~/

5. Ensure the system is running from the BACKUP image, i.e. from
   rcks_wlan.bkup partition or "image 2". Otherwise the installation
   WILL fail, and you will need to access mtd0 device to write image
   which risks overwriting the bootloader, and so is not covered here
   and not supported.

   Switching to backup firmware can be achieved by executing a few
   consecutive reboots of the device, or by updating the stock firmware. The
   system will boot from the image it was not running from previously.
   Stock firmware available to update was conveniently dumped in point 4 :-)

6. Prepare U-boot environment image.
   Install u-boot-tools package. Alternatively, if you build your own
   images, OpenWrt provides mkenvimage in host staging directory as well.
   It is recommended to extract environment from the device, and modify
   it, rather then relying on defaults:

   $ sudo touch /srv/tftp/u-boot-env.bin
   $ sudo chmod 666 /srv/tftp/u-boot-env.bin

   On the device, find the MTD partition on which environment resides.
   Beware, it may change depending on currently active firmware image!

   # grep u-boot-env /proc/mtd

   Now, copy over the partition

   # tftp -l /dev/mtd<N> -r u-boot-env.bin -p 10.42.0.1

   Store the stock environment in a safe place:

   $ cp /srv/tftp/u-boot-env.bin ~/

   Extract the values from the dump:

   $ strings u-boot-env.bin | tee u-boot-env.txt

   Now clean up the debris at the end of output, you should end up with
   each variable defined once. After that, set the bootcmd variable like
   this:

   bootcmd=bootm 0x9f040000

   You should end up with something like this:

bootcmd=bootm 0x9f040000
bootargs=console=ttyS0,115200 rootfstype=squashfs init=/sbin/init
baudrate=115200
ethaddr=0x00:0xaa:0xbb:0xcc:0xdd:0xee
mtdparts=mtdparts=ar7100-nor0:256k(u-boot),13312k(rcks_wlan.main),2048k(datafs),256k(u-boot-env),512k(Board Data),13312k(rcks_wlan.bkup)
mtdids=nor0=ar7100-nor0
bootdelay=2
ethact=eth0
filesize=78a000
fileaddr=81000000
partition=nor0,0
mtddevnum=0
mtddevname=u-boot
ipaddr=10.0.0.1
serverip=10.0.0.5
stdin=serial
stdout=serial
stderr=serial

   These are the defaults, you can use most likely just this as input to
   mkenvimage.

   Now, create environment image and copy it over to TFTP root:

   $ mkenvimage -s 0x40000 -b -o u-boot-env.bin u-boot-env.txt
   $ sudo cp u-boot-env.bin /srv/tftp

   This is the same image, gzipped and base64-encoded:

H4sIAAAAAAAAA+3QQW7TQBQAUF8EKRtQI6XtJDS0VJoN4gYcAE3iCbWS2MF2Sss1ORDYqVq6YMEB3rP0
Z/7Yf+aP3/56827VNP16X8Zx3E/Cw8dNuAqDYlxI7bcurpu6a3Y59v3jlzCbz5eLECbt8HbT9Y+HHLvv
x9TdbbpJVVd9vOxWVX05TotVOpZt6nN8qilyf5fKso3hIYTb8JDSEFarIazXQyjLIeRc7PvykNq+iy+T
1F7PQzivmzbcLpYftmfH87G56Wz+/v18sT1r19vu649dqi/2qaqns0W4utmelalPm27I/lac5/p+OluO
NZ+a1JaTz8M3/9hmtT0epmMjVdnF8djXLZx+TJl36TEuTlda93EYQrGpdrmrfuZ4fZPGHzjmp/vezMNJ
MV6n6qumPm06C+MRZb6vj/v4Mk/7HJ+6LarDqXweLsZnXnS5vc9tdXheWRbd0GIdh/Uq7cakOfavsty2
z1nxGwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAD+1x9eTkHLAAAEAA==

7. Perform actual installation. Copy over OpenWrt sysupgrade image to
   TFTP root:

   $ sudo cp openwrt-ath79-generic-ruckus_zf7321-squashfs-sysupgrade.bin /srv/tftp

   Now load both to the device over TFTP:

   # tftp -l /tmp/u-boot-env.bin -r u-boot-env.bin -g 10.42.0.1
   # tftp -l /tmp/openwrt.bin -r openwrt-ath79-generic-ruckus_zf7321-squashfs-sysupgrade.bin -g 10.42.0.1

   Vverify checksums of both images to ensure the transfer over TFTP
   was completed:

   # sha256sum /tmp/u-boot-env.bin /tmp/openwrt.bin

   And compare it against source images:

   $ sha256sum /srv/tftp/u-boot-env.bin /srv/tftp/openwrt-ath79-generic-ruckus_zf7321-squashfs-sysupgrade.bin

   Locate MTD partition of the primary image:

   # grep rcks_wlan.main /proc/mtd

   Now, write the images in place. Write U-boot environment last, so
   unit still can boot from backup image, should power failure occur during
   this. Replace MTD placeholders with real MTD nodes:

   # flashcp /tmp/openwrt.bin /dev/<rcks_wlan.main_mtd>
   # flashcp /tmp/u-boot-env.bin /dev/<u-boot-env_mtd>

   Finally, reboot the device. The device should directly boot into
   OpenWrt. Look for the characteristic power LED blinking pattern.

   # reboot -f

   After unit boots, it should be available at the usual 192.168.1.1/24.

Return to factory firmware:

1. Boot into OpenWrt initramfs as for initial installation. To do that
   without disassembly, you can write an initramfs image to the device
   using 'sysupgrade -F' first.
2. Unset the "bootcmd" variable:
   fw_setenv bootcmd ""
3. Write factory images downloaded from manufacturer website into
   fwconcat0 and fwconcat1 MTD partitions, or restore backup you took
   before installation:
   mtd write ruckus_zf7321_fw1_backup.bin /dev/mtd1
   mtd write ruckus_zf7321_fw2_backup.bin /dev/mtd5
4. Reboot the system, it should load into factory firmware again.

Quirks and known issues:
- Flash layout is changed from the factory, to use both firmware image
  partitions for storage using mtd-concat, and uImage format is used to
  actually boot the system, which rules out the dual-boot capability.
- The 5GHz radio has its own EEPROM on board, not connected to CPU.
- The stock firmware has dual-boot capability, which is not supported in
  OpenWrt by choice.
  It is controlled by data in the top 64kB of RAM which is unmapped,
  to avoid   the interference in the boot process and accidental
  switch to the inactive image, although boot script presence in
  form of "bootcmd" variable should prevent this entirely.
- U-boot disables JTAG when starting. To re-enable it, you need to
  execute the following command before booting:
  mw.l 1804006c 40
  And also you need to disable the reset button in device tree if you
  intend to debug Linux, because reset button on GPIO0 shares the TCK
  pin.
- On some versions of stock firmware, it is possible to obtain root shell,
  however not much is available in terms of debugging facitilies.
  1. Login to the rkscli
  2. Execute hidden command "Ruckus"
  3. Copy and paste ";/bin/sh;" including quotes. This is required only
     once, the payload will be stored in writable filesystem.
  4. Execute hidden command "!v54!". Press Enter leaving empty reply for
     "What's your chow?" prompt.
  5. Busybox shell shall open.
  Source: https://alephsecurity.com/vulns/aleph-2019014

Signed-off-by: Lech Perczak <lech.perczak@gmail.com>
(cherry picked from commit f1d112ee5a43e8c4a22db05b94bbcd0677a34486)