[U-Boot-Users] MPC8272ADS Hangs with gcc 4.0.0 and u-boot 1.1.4

[Wolfgang Denk]

In message <af313df20602010929j1b6d8e7aqce025acfd1803ae5 at mail.gmail.com> you wrote:
> 
> I have ELDK 3.1 and ELDK 4.0 installed. I'm using U-Boot 1.1.4. When I
> compile U-Boot with GCC 3.3.3, the board works ok, but not with GCC
> 4.0.0. All the ethernet leds freeze turned on and the Run led too. It
> makes me thinking the board entered some loop state. Nothing appears
> at serial port.

This is possible. GCC-4.x has much better optimization, and  punishes
bad code. We have seen problems like this in many drivers, especially
in the 2.4 kernel code.

> If anyone had this problem, or if anyone have such a configuration
> working (GCC 4 and U-Boot 1.1.4 with this board), any help will be
> very appreciated.

We have U-Boot working on many other boards, and  obviously  we  have
been  using  GCC  4.0 as included with ELDK 4.0 for some time now. We
did not encounter such problems, so it is  probably  some  MPC8272ADS
board  specific  code.  Typically effects like this one are caused by
missing "volatile" attributes - the  older  compilers  generate  code
which  the new compiler optimizes away - check accesses to MPC8272ADS
speific  devices  (BCSR   etc.?)   if   they   have   the   necessary
"volatile"s...

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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