Coldfire uC5282 Question

Wed Mar 31 00:43:33 UTC 2010

Hi,

I think I have found the bug.  gcc/Makefile.in generates a site.exp
for the DejaGNU test harness.  Most of the "board.exp" files use
the newlib_ldflag set in generated site.exp but we should not.
I am adjusting the RTEMS boards.exp to ignore this variable.

Till... is there a way to exit qemu-uC5282 automatically?  Or
does the BSP need to end with an illegal instruction or something?
We need it to cleanly exit or the tests run forever.

--joel

On 03/30/2010 06:06 PM, Eric Norum wrote:
> Multilib version 5208 sounds right.   It should have the same CPU32 
> core as the 5282, or a least pretty close.  For sure the 5208 won't 
> have DBCC, either.
>
> I tried the following little C program:
> #include <string.h>
> char *cp;
> main()
> {
>     memset (cp, 5, 100);
>     return 0;
> }
>
>
> And compiled it with:  m68k-rtems4.10-gcc -mcpu=5282 -v -O4  m.c
> The link edit stage was:
> /usr/local/rtems/rtems-4.10/libexec/gcc/m68k-rtems4.10/4.4.2/collect2 
> /usr/local/rtems/rtems-4.10/lib/gcc/m68k-rtems4.10/4.4.2/../../../../m68k-rtems4.10/lib/m5208/crt0.o 
> -L/usr/local/rtems/rtems-4.10/lib/gcc/m68k-rtems4.10/4.4.2/m5208 
> -L/usr/local/rtems/rtems-4.10/lib/gcc/m68k-rtems4.10/4.4.2/../../../../m68k-rtems4.10/lib/m5208 
> -L/usr/local/rtems/rtems-4.10/lib/gcc/m68k-rtems4.10/4.4.2 
> -L/usr/local/rtems/rtems-4.10/lib/gcc/m68k-rtems4.10/4.4.2/../../../../m68k-rtems4.10/lib 
> /var/folders/B3/B3Xa8pTJEEm4plqQBpCki++++TU/-Tmp-//ccqTTObt.o -lgcc 
> -lc -lgcc
>
>
> A gdb disassem reveals:
> (gdb) disassem memset
> Dump of assembler code for function memset:
> 0x80000490 <memset+0>: moveal %sp@(4),%a0
> 0x80000494 <memset+4>: movel %sp@(8),%d0
> 0x80000498 <memset+8>: movel %sp@(12),%d1
> 0x8000049c <memset+12>: cmpil #16,%d1
> 0x800004a2 <memset+18>: bcsw 0x800004f0 <memset+96>
> 0x800004a6 <memset+22>: movel %d2,%sp at -
> 0x800004a8 <memset+24>: moveb %d0,%d2
> 0x800004aa <memset+26>: lsll #8,%d0
> 0x800004ac <memset+28>: moveb %d2,%d0
> 0x800004ae <memset+30>: movew %d0,%d2
> 0x800004b0 <memset+32>: swap %d0
> 0x800004b2 <memset+34>: movew %d2,%d0
> 0x800004b4 <memset+36>: movel %a0,%d2
> 0x800004b6 <memset+38>: negl %d2
> 0x800004b8 <memset+40>: andil #3,%d2
> 0x800004be <memset+46>: beqw 0x800004d4 <memset+68>
> 0x800004c2 <memset+50>: subl %d2,%d1
> 0x800004c4 <memset+52>: lsrl #1,%d2
> 0x800004c6 <memset+54>: bccw 0x800004cc <memset+60>
> 0x800004ca <memset+58>: moveb %d0,%a0 at +
> 0x800004cc <memset+60>: lsrl #1,%d2
> 0x800004ce <memset+62>: bccw 0x800004d4 <memset+68>
> 0x800004d2 <memset+66>: movew %d0,%a0 at +
> 0x800004d4 <memset+68>: movel %d1,%d2
> 0x800004d6 <memset+70>: lsrl #2,%d2
> 0x800004d8 <memset+72>: subql #1,%d2
> 0x800004da <memset+74>: movel %d0,%a0 at +
> 0x800004dc <memset+76>: subql #1,%d2
> 0x800004de <memset+78>: bplw 0x800004da <memset+74>
> 0x800004e2 <memset+82>: andil #3,%d1
> 0x800004e8 <memset+88>: movel %sp at +,%d2
> 0x800004ea <memset+90>: braw 0x800004f0 <memset+96>
> 0x800004ee <memset+94>: moveb %d0,%a0 at +
> 0x800004f0 <memset+96>: subql #1,%d1
> 0x800004f2 <memset+98>: bplw 0x800004ee <memset+94>
> 0x800004f6 <memset+102>: movel %sp@(4),%d0
> 0x800004fa <memset+106>: rts
> End of assembler dump.
>
>
> No DBCC there.
>
> FWIW, I repeated the test with: m68k-rtems4.10-gcc -mcpu=68020 -v -O4  m.c
>
> And, I did in fact get a dbf:
> (gdb) disassem memset
> Dump of assembler code for function memset:
> 0x80000490 <memset+0>: moveal %sp@(4),%a0
> 0x80000494 <memset+4>: movel %sp@(8),%d0
> 0x80000498 <memset+8>: movel %sp@(12),%d1
> 0x8000049c <memset+12>: cmpil #16,%d1
> 0x800004a2 <memset+18>: bcsw 0x800004f8 <memset+104>
> 0x800004a6 <memset+22>: movel %d2,%sp at -
> 0x800004a8 <memset+24>: moveb %d0,%d2
> 0x800004aa <memset+26>: lsll #8,%d0
> 0x800004ac <memset+28>: moveb %d2,%d0
> 0x800004ae <memset+30>: movew %d0,%d2
> 0x800004b0 <memset+32>: swap %d0
> 0x800004b2 <memset+34>: movew %d2,%d0
> 0x800004b4 <memset+36>: movel %a0,%d2
> 0x800004b6 <memset+38>: negl %d2
> 0x800004b8 <memset+40>: andil #3,%d2
> 0x800004be <memset+46>: beqw 0x800004d4 <memset+68>
> 0x800004c2 <memset+50>: subl %d2,%d1
> 0x800004c4 <memset+52>: lsrl #1,%d2
> 0x800004c6 <memset+54>: bccw 0x800004cc <memset+60>
> 0x800004ca <memset+58>: moveb %d0,%a0 at +
> 0x800004cc <memset+60>: lsrl #1,%d2
> 0x800004ce <memset+62>: bccw 0x800004d4 <memset+68>
> 0x800004d2 <memset+66>: movew %d0,%a0 at +
> 0x800004d4 <memset+68>: movel %d1,%d2
> 0x800004d6 <memset+70>: lsrl #2,%d2
> 0x800004d8 <memset+72>: subql #1,%d2
> 0x800004da <memset+74>: movel %d0,%a0 at +
> 0x800004dc <memset+76>: dbf %d2,0x800004da <memset+74>
> 0x800004e0 <memset+80>: subil #65536,%d2
> 0x800004e6 <memset+86>: bplw 0x800004da <memset+74>
> 0x800004ea <memset+90>: andil #3,%d1
> 0x800004f0 <memset+96>: movel %sp at +,%d2
> 0x800004f2 <memset+98>: braw 0x800004f8 <memset+104>
> 0x800004f6 <memset+102>: moveb %d0,%a0 at +
> 0x800004f8 <memset+104>: dbf %d1,0x800004f6 <memset+102>
> 0x800004fc <memset+108>: movel %sp@(4),%d0
> 0x80000500 <memset+112>: rts
> 0x80000502 <memset+114>: nop
> End of assembler dump.
>
> On Mar 30, 2010, at 3:26 PM, Joel Sherrill wrote:
>>>
>>
>> Thanks for all the help.  I have tracked it down to memset()
>> which is definitely in assembly in newlib 1.18.0. Hmmm...
>> This output from the -v on the link doesn't look like it used
>> the right multilib:
>>
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/testsuite/gcc/' '-v'
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/collect-ld -dc -dp -N -o 
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/testsuite/gcc/zero-struct-2.x7 
>> /users/joel/test-gcc/install-svn/m68k-rtems4.10/uC5282/lib/start.o 
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/m5208/crti.o 
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/m5208/crtbegin.o -e start 
>> -L/users/joel/test-gcc/b-gcc1-m68k/m68k-rtems4.10/./newlib 
>> -L/users/joel/test-gcc/b-gcc1-m68k/gcc/m5208 
>> -L/users/joel/test-gcc/b-gcc1-m68k/gcc 
>> -L/users/joel/test-gcc/install-svn/m68k-rtems4.10/uC5282/lib 
>> -L/users/joel/test-gcc/b-gcc1-m68k/m68k-rtems4.10/./newlib 
>> /tmp/ccBTk1gL.wpa.ltrans.o gcc_tg.o 
>> /users/joel/test-gcc/b-gcc1-m68k/rtems_gcc_main.o -wrap exit -wrap 
>> _exit -wrap main -wrap abort -lm -lgcc --start-group -lrtemsbsp 
>> -lrtemscpu -lc -lgcc --end-group -T 
>> /users/joel/test-gcc/install-svn/m68k-rtems4.10/uC5282/lib/linkcmds 
>> -lgcc /users/joel/test-gcc/b-gcc1-m68k/gcc/m5208/crtend.o 
>> /users/joel/test-gcc/b-gcc1-m68k/gcc/m5208/crtn.o
>>
>> -mcpu=5282
>>
>> I don't see any explicit matches on 5282 in t-mlibs.  Suggestions
>> on how to fix this appreciated.  This is an ugly file. :(
>>
>> --joel
>>
>
> -- 
> Eric Norum
> wenorum at lbl.gov <mailto:wenorum at lbl.gov>
>
>
>