Xilinx PLB UART

[Shamile Khan]

Hi,

Just a followup on the problem we were having. For now, we
removed IS-BRAM and DS-BRAM from our design. That seems to
solve the problem and we can boot Linux all the way. We had
them in the design originally for potential future use. We
werent really using them which makes it odd why having them
in the design or not having them would make any difference.
We will investigate the issue soon. If you have any
information, we will be really interested.

Thanks,
Shamile


--- Peter Ryser <Peter.Ryser at xilinx.com> wrote:
> We are not aware of any issues with the PLB Uart. As a
> matter of fact,
> since your posting I tried the PLB Uart both in 16450 as
> well as in
> 16550A mode on the ML300 and both ways the Linux kernel
> booted fine and
> showed normal behavior when accessed through the serial
> console. For
> this test I've used the kernel shipping with MontaVista
> Linux 3.0
> (2.4.18) and used the MLD technology of EDK to generate
> the proper BSP
> for Linux.
>
> Send me private mail if you want to have a copy of the
> EDK project with
> the PLB Uart.
>
> Some things to look for in your project:
> - make sure the address map of the PLB Uart does not
> overlap with the
> address region of the PLB2OPB bridge.
> - use recent tools and the most recent cores available
> (e.g. EDK 6.1.2
> and PLB Uart v1_00_c).
> - use the MLD technology in EDK to generate a BSP for
> your Linux kernel.
> With that you will automatically avoid problems with
> interrupt mapping
> and similar things.
> - for all new designs use EDK (vs V2PDK).
> - start with the EDK reference design for ML300 available
> from
> http://www.xilinx.com/ise/embedded/edk_examples.htm
> (design # 6). You
> can modify this design to match your board.
>
> Cheers,
> - Peter
>
>
> Shamile Khan wrote:
>
> >Hi,
> >
> >This question concerns Xilinx Virtex II Pro platform. We
> >have been using OPB UART for Linux. We just tried to
> switch
> >from OPB UART to PLB UART. We have interrupts enabled.
> So
> >the kernel boots till
> >
> >Freeing unused kernel memory: 40k init
> >
> >At this point, I dont see anything on the screen. I dont
> >even see the slow display of characters on the screen
> >implying that the kernel has switched to polling mode. I
> >didnt change anything for the kernel as I expected the
> OPB
> >UART functionality to be identical to PLB UART from
> >processor's perspective. Are you aware of any issues
> >concerning PLB UART for Linux?
> >
> >Thanks,
> >Shamile
> >
> >
> >
> >
>


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