vxWorks and Cyclone V SoC HPS->FPGA bridge

Altera_Forum · ‎03-26-2014

Hello,

I am very new with vxWorks and Altera. I normally work with QNX and Xilinx.

I have tuned a vxworks image. I have test some tasks in RTP and DKM modes.

Fron DKM I can read from physical memory without problem, but when I try to read from the HPS->FPGA(lw) bridge I get an exception from the operating System.

The HPS->FPGA bridge that I am using is mapped at 0xFF200000 and I have some peripheral at 0xFF210000 and 0xFF220000.

I have checked these peripheral with Linux and it works well (I can read and write).

My boot sequence is Preloader -> u-boot(Configure the fpga and bridges) -> bootrom -> vxWorks

and for Linux Preloader -> u-boot(Configure the fpga and bridges) -> Linux

Have you ever tried to read something from the FPGA with vxWorks?

Maybe the problem is that the initialization of vxworks (bootrom) does something and change the configuration of the HPS->FPGA bridge.

In my task I check that the clock to the bridge is enable, the bridge is out of reset, and the FPGA is configured I have some output connected to the peripherals.

I have checked that in the configuration of the MMU in the file "config.h" of the BSP exist a mapped range from 0xFF000000 to 0xFFFF0000 and my devices are inside this range.

Thanks a lot in advance. I am getting crazy because I cannot find any documentation about vxWorks.

I think that is better if I publish this problem in the vxWorks forum, but for now I only have 30 days trial license and I cannot access to vxWorks support (I think).

Thanks,

Jonathan.

Altera_Forum · ‎03-26-2014

Hello,

I got it to work!!!

I have had to write to register 0xff800000 the value 0x00000010 to mark LWH2F accesible.

I think that the initialization of vxWorks clears this register.

This has been a hard work, are there some pdf with every register address and the meaning of each bit?

I have had to follow a code without comments to get it to work.

Thanks a lot,

Jonathan.

Altera_Forum · ‎03-26-2014

You can find register definitions in http://www.altera.com/literature/lit-cyclone-v.jsp They are in handbook volume 3 section IX. Both PDF and HTML versions are available. Note that this wasn't included when I downloaded the handbook.

Altera_Forum · ‎03-26-2014

I use this link all the time: http://www.altera.com/literature/hb/cyclone-v/hps.html

Registers are not always named appropriately or located intuitively. I find that the "expand all" option and searching through the results can be pretty effective when I really don't know where to look. :-)

For instance, another potential and somewhat common cause for bridge misbehavior is inadvertently holding the bridges in reset. This is different than the issue you had, but...

Cheers!

slacker