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pc386 on 386sx



I have problems with two boards that do not have co-processors.  One
board is an ACER PIA-632 with an ALI chipset -- a 386sx "clone", the
other a PC clone with an Intel 486sx.   In both cases, they fail during
CPU_initialize, in cpu.c.

Even though the no-wait form of the math co-processor init instruction
is used ( fninit ), "Exception 7"  is generated, gets trapped by the
exception management code, and prints the screen dump.  This happens in
an infinite loop.  (  Pictures of the screen were taken with a digital
camera to get that info.  At the point of failure,  ax contains 0xa5a5,
which is what fp_status is set to prior to the fninit and fnstsw
instructions.  )

After fninit and fnstsw instructions were commented out,  hello world,
ticker and cdtest now all work.

Note that the test in cpuModel.S did not have to be commented out!

Why should this instruction fail in CPU_Initialize for these cpu's?  It
is fine for the i386ex.  In all cases, the RTEMS_CPU_MODEL is i386_nofp.

Can this be fixed so that the code can be uncommented? I don't want to
be that out of step with the distribution.

Thanks






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