[U-Boot] [PATCH 1/1] net: Add Xilinx LL Temac driver version2

[Ben Warren]

Hi Michal,

Michal Simek wrote:
> Hi Ben,
>   
>> Hi Michal,
>>
>> Michal Simek wrote:
>>
>> <snip>
>>     
>>>> All of the above mentioned issues are ones that I could easily deal
>>>> with, but one thing that really does need to change is that you need to
>>>> use the CONFIG_NET_MULTI API.  In other words, your driver should have a
>>>> single initialize() function (prototyped in include/netdev.h), and an
>>>> eth_device struct that gets registered.  All your access functions
>>>> (eth_init, eth_send, eth_recv etc.) will be static and pointed to by the
>>>> eth_device struct.  Most drivers are already this way.
>>>>     
>>>>         
>>> I look at it and I did some change and the main problem is in
>>> Microblaze GCC.
>>> We use GCC 3.4.1 and CONFIG_NET_MULTI use weak function and
>>> board_eth_init is
>>> never called. We are working on GCC 4.1.2 but I don't know when I get it.
>>>
>>>   
>>>       
>> According to the documentation I could find, weak symbols were present
>> in gcc 3.4.1.  Are you sure you're using them properly?  Due to the way
>> linking is performed in U-boot, any weak symbol overrides need to be in
>> source files that have strongly linked symbols.  You'll see that all
>> implementations of cpu_eth_init() and board_eth_init() are in files that
>> already contain stuff that is sure to be linked.
>>     
>
>
> hmm. I did some tests and I found that the my problem is with this line 40. (I
> use board_eth_init initialization)
> int board_eth_init(bd_t *bis) __attribute((weak, alias("__def_eth_init")));
> I am not gcc specialist but I smell problem with GCC.
>
>   
This essentially says "board_eth_init() = __def_eth_init() unless 
overridden by a strongly linked function".  Here's how I debug this 
stuff, and you don't need to instrument your code or even run it to know 
if the linking worked properly:

Look in the System.map file that the build system generates (it's 
human-readable).   If there are no overriding functions, you'd expect 
that the addresses of __def_eth_int(), cpu_eth_init() and 
board_eth_init() to be identical.  If YOUR board_eth_init() is linked 
in, it will have a different address.  That's it!

regards,
Ben