Sorry to come up with something very old. Since I am currently teaching myself hardware hacking, I wanted to use my old router for this. I soldered pins to the JTAG interface and connected them to my Pi2 GPIO. I connected them as follows: Unfortunately, I cannot dump the firmware because the device does not want to switch to halt. Only time-out for halt request appears.
I have changed the freq, checked for cold solder joints. (I don't have any errors)
init reset halt JTAG tap: bcm5352e.cpu tap/device found: 0x0535217f (mfg: 0x0bf, part: 0x5352, ver: 0x0) Halt timed out, wake up GDB. timed out while waiting for target halted TARGET: bcm5352e.cpu - Not halted