Experimental Physics and
Industrial Control System

Rolf Keitel <[email protected]> · Tue, 15 Apr 1997 10:02:56 -0700

Hello Andrew,

I am trying to get our CAN-bus system going and ran into the following
problem with our
GNU cross-compiler. I am running Solaris 2.5,  and the cross-compiler
version is:

> cc68k -v
Reading specs from
/usr/local/gnu/solaris.68k/lib/gcc-lib/m68k-wrs-vxworks/cygnus-2.2.3.1/specs
gcc version cygnus-2.2.3.1

The offending code is in drvIpac.c in the routine ipmCheck:

    if (id->asciiI != 'I' || id->asciiP != 'P' || id->asciiA != 'A' ||
id->asciiC != 'C')
    {
	return S_IPAC_noIpacId;
    }
    return OK;

This piece of code returns S_IPAC_noIpacId. 

A control printout of the involved variables shows that the return
should be OK:

    printf("\n%x: %c %c %c %c\n", id, id->asciiI, id->asciiP,
id->asciiA, id->asciiC);
    printf("%x %x %x %x\n", id->asciiI, id->asciiP, id->asciiA,
id->asciiC);
    printf("%x %x %x %x\n", 'I', 'P', 'A', 'C');

-- start of control printout 
fff58080: I P A C
49 50 41 43
49 50 41 43

ipmCheck returns 2580006
value = 39321606 = 0x2580006
-- end of control printout

If I change the code to individual comparisons,
the return is OK: 

    if (id->asciiI != 'I')
    {
	return S_IPAC_noIpacId;
    }
    if (id->asciiP != 'P')
    {
	return S_IPAC_noIpacId;
    }
    if (id->asciiA != 'A')
    {
	return S_IPAC_noIpacId;
    }
    if (id->asciiC != 'C')
    {
	return S_IPAC_noIpacId;
    }
    return OK;

If I define intermediate variables, the return is also OK:

    uchar_t I, P, A, C;

    I = id->asciiI;
    P = id->asciiP;
    A = id->asciiA;
    C = id->asciiC;

    if (id->asciiI != 'I' || id->asciiP != 'P' || id->asciiA != 'A' ||
id->asciiC != 'C')
    {
	return S_IPAC_noIpacId;
    }
    return OK;

My make file produces the following compiler command line.

 > make
/usr/local/gnu/solaris.68k/bin/cc68k
-B/usr/local/gnu/solaris.68k/lib/gcc-lib/
  -c -O -W -m68040 -nostdinc -DV5_vxWorks -DvxWorks -DTARGET_OS=vxWorks
-DCPU=MC68040 
  -DV5_vxWorks -DCPU_FAMILY=MC680X0  -I../src -I../epicsH
-I../epicsH/rec 
  -I../vw/h ../src/drvIpac.c

Is this a known problem? 

				- rolf -

-- 
+----------------------------------------------------------+
: Rolf Keitel                |    [email protected]           :
: TRIUMF                     |    Tel: (604) 222-7453      :
: 4004 Wesbrook Mall         |    Fax: (604) 222-7307      :
: Vancouver, B.C., V6T 2A3   |    www.triumf.ca            :
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System