[U-Boot] PPC405 with XMD boot

[U-Boot] PPC405 with XMD boot

[Frank Lombardo]

Rommel,

I am using your recently posted patch to boot my custom Virtex4 board with
XMD.  Execution gets stuck in the NS16550_init() function.  It gets stuck
at this line:

#if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT))
    while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
        ;
#endif

If I define CONFIG_SYS_NS16550_BROKEN_TEMT, it gets stuck in the while loop
in NS16550_putc:

    while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
        ;
    serial_out(c, &com_port->thr);

[U-Boot] PPC405 with XMD boot

[Rommel G Custodio]

Dear Frank,

On 2013.02/05, Frank Lombardo wrote:
> Rommel,
> 
> I am using your recently posted patch to boot my custom Virtex4 board with
> XMD.  Execution gets stuck in the NS16550_init() function.  It gets stuck
> at this line:

So you're not jumping to random addresses anymore.

> 
> #if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT))
>     while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
>         ;
> #endif
> 
> If I define CONFIG_SYS_NS16550_BROKEN_TEMT, it gets stuck in the while loop
> in NS16550_putc:
> 
>     while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
>         ;
>     serial_out(c, &com_port->thr);
> 
> From the GDB output, I can see it is using the correct address for the the
> serial port (0x84000000)

Hmmn. I've seen that before, I think.
Don't define CONFIG_SYS_NS16550_BROKEN_TEMT.

Make sure you use CTS/RTS (h/w flow) control with your terminal
application.

HTH.

All the best,
Rommel

> 
> (gdb) target remote localhost:1234
> Remote debugging using localhost:1234
> NS16550_putc (com_port=0x84000000, c=13 '\r') at ns16550.c:91
> 91        while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
> (gdb)
> 
> 
> In your opinion, is your patch providing everything that I need to boot
> with XMD?  Can you suggest what I might be doing wrong?
> 
> Thanks for any insight you may have,
> Frank
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[U-Boot] PPC405 with XMD boot

[Stefan Roese]

On 02/06/2013 12:13 PM, Rommel G Custodio wrote:
>> If I define CONFIG_SYS_NS16550_BROKEN_TEMT, it gets stuck in the while loop
>> in NS16550_putc:
>>
>>     while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
>>         ;
>>     serial_out(c, &com_port->thr);
>>
>> From the GDB output, I can see it is using the correct address for the the
>> serial port (0x84000000)
> 
> Hmmn. I've seen that before, I think.
> Don't define CONFIG_SYS_NS16550_BROKEN_TEMT.

That should not be necessary.

> Make sure you use CTS/RTS (h/w flow) control with your terminal
> application.

Are you sure that all clocks, especially those related with the UART
controller, are configured correctly?

Thanks,
Stefan

[U-Boot] PPC405 with XMD boot

[Frank Lombardo]

Thanks for the responses guys.  I got to work.  What I found was that the
address being passed to the driver code was 0x84000000.  This is the base
address of the UART.  However, the registers of the XPS 16550 UART are
offset by 0x1000 from the base.  I changed the base address in my
xparameters.h file, but I wonder, should this be taken care of in a better
way?


On Wed, Feb 6, 2013 at 9:08 AM, Stefan Roese <sr@denx.de> wrote:

> On 02/06/2013 12:13 PM, Rommel G Custodio wrote:
> >> If I define CONFIG_SYS_NS16550_BROKEN_TEMT, it gets stuck in the while
> loop
> >> in NS16550_putc:
> >>
> >>     while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
> >>         ;
> >>     serial_out(c, &com_port->thr);
> >>
> >> From the GDB output, I can see it is using the correct address for the
> the
> >> serial port (0x84000000)
> >
> > Hmmn. I've seen that before, I think.
> > Don't define CONFIG_SYS_NS16550_BROKEN_TEMT.
>
> That should not be necessary.
>
> > Make sure you use CTS/RTS (h/w flow) control with your terminal
> > application.
>
> Are you sure that all clocks, especially those related with the UART
> controller, are configured correctly?
>
> Thanks,
> Stefan
>
>

[U-Boot] PPC405 with XMD boot

[Stefan Roese]

On 02/07/2013 04:20 AM, Frank Lombardo wrote:
> Thanks for the responses guys.  I got to work.  What I found was that
> the address being passed to the driver code was 0x84000000.  This is the
> base address of the UART.  However, the registers of the XPS 16550 UART
> are offset by 0x1000 from the base.  I changed the base address in my
> xparameters.h file, but I wonder, should this be taken care of in a
> better way?

I'm afraid, but I have never really worked with the Xilinx PPC4xx
FPGA's. So my knowledge here is "limited". Sorry, but I can't help more.

Thanks,Stefan

[U-Boot] PPC405 with XMD boot

[Rommel Custodio]

Stefan Roese <sr <at> denx.de> writes:

> 
> On 02/07/2013 04:20 AM, Frank Lombardo wrote:
> > Thanks for the responses guys.  I got to work.  What I found was that
> > the address being passed to the driver code was 0x84000000.  This is the
> > base address of the UART.  However, the registers of the XPS 16550 UART
> > are offset by 0x1000 from the base.  I changed the base address in my
> > xparameters.h file, but I wonder, should this be taken care of in a
> > better way?
> 
> I'm afraid, but I have never really worked with the Xilinx PPC4xx
> FPGA's. So my knowledge here is "limited". Sorry, but I can't help more.

I think include/configs/microblaze-generic.h includes code for this.

The ML-series all now use UARTlite in the configs. Though maybe it won't
hurt to add code similar to the MB in the ML-series headers as a fallback.

All the best,
Rommel