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From: Matthias Alles on 25 Jul 2008 07:44
Hi!

I'm encountering a nasty bug when using the xilkernel with floating point.
I have an application that uses the FPU (connected via APU) to the
PPC440 (EDK 10.1 SP2). When I run the application standalone everything
works fine. However, when I use xilkernel and use my application as
starting thread execution stops after some time.

I debugged this behaviour and can see, that the CPU issues an alignment
exception all the time (remaining at the same instruction). The problem
occurs in different regions of the program, depending on the code
structure or whatever.
For instance in _vprintf_r there is an instruction(stfd = store floating
point double):

stfd f30, 1760(r1) with r1 = 0x0111ed1a

The resulting address is not aligned to an 8-byte boundary which causes
the exception. It seems that the stack for the thread is not aligned to
an 8-byte boundary. Looks like a xilkernel bug.

Has anyone ever seen the same behaviour? How can I solve this problem?

Thanks!
Matthias Alles
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