Re: problem with standard libc on 8xx

In message [off-list ref] you wrote:

I created my own root-fs for a MPC8xx platform
using standard Debian packages (including libc).
When I start the system, the init scripts hangs

...

I guess that the Debian libc uses floating point - which

Thi sis definitely one cause of the problem.  Another  one  might  be
optimization  for  a  incorrect  cache  line  size  (32 instead of 16
bytes).

is not available on MPC8xx - but I thougt the kernel would
emulate this calls (CONFIG_MATH_EMULATION=y).

This has never been working reliably for any real-life code. And it's
awfully slow.

Also note that you CANNOT mix standard binaries (from Debian) and 8xx
specific libraries (from ELDK) -  this  will  crash  as  soon  as  an
application attempts to use floating point.


Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Above all else -- sky.

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

In message
<9CFB9DA5261CD611A29B00508B78904807F880ED@ex-deu-munich02.forc
e.de> you wrote:

quoted

I created my own root-fs for a MPC8xx platform
using standard Debian packages (including libc).
When I start the system, the init scripts hangs

...

quoted

I guess that the Debian libc uses floating point - which

Thi sis definitely one cause of the problem.  Another  one  might  be
optimization  for  a  incorrect  cache  line  size  (32 instead of 16
bytes).

Also, you must make sure you don't use any cache instructions such
as dcbz. I believe the optimized memset function i glibc uses dcbz.

The mpc8xx CPU has a HW bug which makes the TLB exceptions fail
for most cache instructions. There is a workaround for this, but it
is somewhat ugly. Search the embedded archives if you want to known more.

   Jocke

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/