The Mercury MAC1200R (TPLINK WR6300) is one of the cheapest AC based routers on the planet, as I have a few AC devices I thought I’d buy one to try out. They’re available for under RMB120 or so online.

Mercury hardware is TPLink hardware, albeit using a different name. Same stuff, same factory, different casing.

The router has 64M ram, and 8M flash. CPU / Wifi AR9344 / QCA9882

OpenWRT says it has support, so I had a quick go at taking a look at flashing one.

First steps:

Open up the unit (remove the 2 screws underneath, then use a spare credit card or similar to jam open the plastic case).

The serial headers are to the right of the SoC.
You’ll need a rs232 to ttl or usb to ttl adaptor.

Pin 1 is GND
Pin 2 is TX (connect to rx)
Pin 3 is RX (connect to tx)
Pin 4 is VCC (don’t connect).

Port speeds are 115200,8,n,1

Connect up, and you should see a flurry of activity on boot.

To get into the bootloader (uBoot), you’ll need to type tpl
May take a few tries, so prepare to pull power and retry again, and again till you get in.

You’ll need a TFTPD server running on 192.168.1.100 to push files over. My Mac no haz ethernet (and Thunderbolt to Ethernet is crud), so I use my venerable X40 and tftpd software.

Firmware is up here. (Or you can compile your own) -> http://pan.baidu.com/s/1hqkVOfa

Firmware locations in flash (see below)
printenv
bootargs=console=ttyS0,115200 root=31:02 rootfstype=jffs2 init=/sbin/init mtdparts=ath-nor0:256k(u-boot),64k(u-boot-env),6336k(rootfs),1408k(uImage),64k(mib0),64k(ART)
bootcmd=bootm 0x9f020000
bootdelay=1
baudrate=115200
ethaddr=0xba:0xbe:0xfa:0xce:0x08:0x41
ipaddr=192.168.1.111
serverip=192.168.1.100
dir=
lu=tftp 0x80060000 ${dir}u-boot.bin&&erase 0x9f000000 +$filesize&&cp.b $fileaddr 0x9f000000 $filesize
lf=tftp 0x80060000 ${dir}db12x${bc}-jffs2&&erase 0x9f050000 +0x630000&&cp.b $fileaddr 0x9f050000 $filesize
lk=tftp 0x80060000 ${dir}vmlinux${bc}.lzma.uImage&&erase 0x9f680000 +$filesize&&cp.b $fileaddr 0x9f680000 $filesize
stdin=serial
stdout=serial
stderr=serial
ethact=eth0

Environment size: 686/65532 bytes

Upload to the uBoot

It should boot into OpenWRT, you can flash from there.


...[long kernel bootlogs redacted]

I highly recommend replacing the bootloader with an unlocked one.
i.e. this one – https://github.com/pepe2k/u-boot_mod

Bootloader sits at 0x9f000000 and is 64kb in size.
Suggest load in ram at 0x80060000 like they do, and flash from there.

eg from the bootloader –

tfpboot 0x80060000 uboot.bin
erase 0x9f000000 +0x20000
cp.b 0x80060000 0x9f000000 0x20000


Pray that it didn’t mess up (or you need an spi flasher…), and reboot!

Other bits n bobs –

You’ll need to adjust the opkg.conf file

ssh into the router @ 192.168.1.1 / root / root

mv /etc/opkg.conf /etc/opkg.conf.orig

#src/gz barrier_breaker_base http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/base
#src/gz barrier_breaker_management http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/management
#src/gz barrier_breaker_oldpackages http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/oldpackages
#src/gz barrier_breaker_packages http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/packages
#src/gz barrier_breaker_routing http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/routing
#src/gz barrier_breaker_telephony http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/telephony' >> /etc/opkg.conf

…and install Luci (the openwrt webui)

opkg update
opkg install luci


You should be able to visit http://192.168.1.1 and start changing settings.

While it is the season to be jolly, its also apparently the season for us to move datacenters!

Our network provider has told us (on rather short notice!) that we need to vacate our current datacentre, and move to a newer larger centre. Its not all bad news though, as it means a chance to refresh equipment, and upgrade services.

We’ll be moving equipment to a newer Shanghai Telecom datacenter in Waigaoqiao on Saturday 27th December. Most of the work has already been done as we’ve setup new equipment for servers, and tested migrating some clients already.

Moving servers does mean we will incur some downtime for some clients on Saturday though.
We will need to change DNS records for you to point to the new location, and migrate some data to new servers.

We anticipate this taking a few hours.

Please bear with us while we migrate services on Saturday 27th December.