November 29, 2022

The Zynq EMUP project -- Set up the EBAZ for the project

I pull a board out of my "supply box" I bought several of these EBAZ boards back when they were dirt cheap, and they have been waiting for a day like this.

The first two things require a soldering iron.

I want to supply power via the "molex" connector and that requires a diode at location D24, What I do is to steal the diode at location D22. This is a bit of somewhat tricky unsoldering and resoldering and it is done.

The second thing is to solder a 4 pin header at location J7 for the serial console. This is quick and easy.

I dig a CP2102 USB to serial gadget out of my drawer (I bought a dozen of these several years ago). I locate 3 jumper wires and connect them to GND, Rx, and Tx. Rx on the Ebaz goes to Tx on the CP2102 board.

Then I apply power (12 volts DC) and away it goes!

I make a stupid mistake which wastes a fair bit of time. I am not watching closely and connect the jumper wire to DTR instead of Tx on the CP2102. This causes no harm, but it means that I can receive characters and watch the boot, but when I try to type 'd' to interrupt U-Boot, there is no response.

After I figure out the misconnected wire, I reset the root password by typing these lines:

nandboot=echo Copying Linux from NAND flash to RAM... && nand info && run nandroot;nand read 0x100000 0x2220000 0x300000 && fpga loadb 0 0x100000 0x300000 && nand read ${kernel_load_address} 0x300000 ${kernel_size} && nand read ${devicetree_load_address} 0x800000 ${devicetree_size}

setenv bootargs 'console=ttyPS0,115200 root=/dev/mtdblock6 rootfstype=jffs2 noinitrd rw rootwait reboot=cold,hard emergency init=/bin/sh'

bootm ${kernel_load_address} - ${devicetree_load_address} init=/bin/sh

And after I finish resetting the password, I also disable the bitcoin mining program:
cd /etc/rcS.d
After this, I reboot and I can login as root using my new password. Quick, simple, and easy.

Have any comments? Questions? Drop me a line!

Programmable devices /