PCI lookup issue: 3c905C-TX not found by RTEMS.

[Karel Gardas]

Hello Gregory,

On Wed, 19 Jan 2005 gregory.menke at gsfc.nasa.gov wrote:

>  > At least I have tried to return 0/8/0 in pbus/pdev/pfun(as OpenBSD dmesg
>  > advices me) from BSP_pciFindDevice when it tries to find first instance of
>  > 10b7/9200 device and now I'm able to get:
>  >
>  > etherlink: device '3Com 3c905C-TX Fast Etherlink XL', name 'elnk1', pci
>  > 00:08.00, 16 rx/16 tx buffers
>  >
>  > output and then RTEMS freeze. I guess rtems/pci is simply kind of broken
>  > on my board and so later (in rtems_elnk_driver_attach function) PCI usage
>  > probably returns incorrect values for ioaddr, interrupt and such. The only
>  > question is if I hack whole rtems_elnk_driver_attach and set all required
>  > parameters manually inside it, if the whole thing will run well and
>  > results in elink correctly initialized and attached -- i.e. I don't know
>  > anything about PCI bus initialization...
>
> This means the pci bus tree is not being configured by your bios.
> Since the i386 RTEMS bootloader doesn't configure the bus tree, then
> the pci address spaces and/or interrupts are not being configured and
> the card cannot work.  Simply assuming base address values is probably
> not going to help because the pci bus bridges have not been configured
> and your i/o transactions will not even make it to the card, and even
> if they do, the interrupt vector has not been configured either.

you are probably right, only one thing makes me wonder, my BIOS prints
listing of PCI devices together with assigned IRQ before booting OS.

> This
> is not the fault of the driver, it assumes the pci bus hardware has
> been configured by a previous step in the boot process.
>
> Assuming the diagnostics are correct so far, you have three
> alternatives;
>
> - get your motherboard to configure the entire pci bus.  If its
>   possible, this will be some setting related to PNP and auto/manual
>   resources.  If its not possible to get your motherboard to do this,
>   then you may have to use a different motherboard.
>
> - lobby and/or provide resources to enhance the pci support on the x86
>   bsp's so a full bus recursion and configuration is done.
>
> - incorporate the pci bus config code from the motorola_shared bsp
>   into the x86 bootloader.  It does a full configuration of all
>   busses, mapping all hardware and assigning irq's- not unlike what
>   Linux/BSD do.  THis is a fairly large project and will probably
>   require attention from the respective bsp maintainers.

thanks for your kind recommendations, I appreciate your help and time which
you have spend on helping me with this issue. Unfortunately I'm not in a
position to be able to do the hacking work myself and also not able to
purchase commercial support to get the work done.

I will probably need to be comfortable with running RTEMS for testing on
my main development machine, which is quite boring to reboot again and
again for testing single changes. My last attempt will be to resolve
network related issues with running RTEMS inside Qemu emulator.

Thanks,
Karel
--
Karel Gardas                  kgardas at objectsecurity.com
ObjectSecurity Ltd.           http://www.objectsecurity.com