PowerPC e7400 executable is type powerpc:e500 making debug difficult

[Peter Dufault]

The PowerPC e7400 executables I built for the PowerPC-Beatnik BSP have an architecture of "powerpc:e500".  I assume it is like this for any powerpc target that includes "ppc_exc_initialize.c". This causes "GDB" to use the wrong size register set in remote debugging, and I couldn't figure out how to convince "gdb" to do something different.  I tried multiple settings but the "bfd_arch_info" wouldn't change from "powerpc:e500" (seen with "maint print architecture") and "gdb" continued to use the wrong register set size.

(gdb) set powerpc vector-abi altivec
(gdb) set arch powerpc:7400
The target architecture is set to "powerpc:7400".
(gdb) set gnutarget powerpc:7400
(gdb) target remote 192.168.240.3:2159
Remote debugging using 192.168.240.3:2159
Remote 'g' packet reply is too long (expected 292 bytes, got 412 bytes): 003a5914007a0ae0007a7b6000000000006577e00052af140052af1c007a0ac80a010014003764ec000000000000000020000000006288500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000645760007a0ae0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000037265c0202b0324000000000376508003764ec00000000fff80000
(gdb) maint print architecture
gdbarch_dump: GDB_NM_FILE = <not-defined>
gdbarch_dump: bfd_arch_info = powerpc:e500
gdbarch_dump: byte_order = 0
gdbarch_dump: byte_order_for_code = 0
(...)

This is because "ppc_exc_initialize.o" has a ".PPC.EMB.apuinfo" section that says it needs the "E500 SPE APU".  Here's what is in that section.

0 | 00000008 | 8 bytes in "APUinfo\0"
4 | 00000008 | 8 bytes (2 words) of APU information.
8 | 00000002 | Section type is rev 2.
12 | "APUinfo\0"
16 | 01000001 | APU 0x100 "e500 SPE APU" revision 1
20 | 00410001 | APU 0x041 "Motorola Book E Performance Monitor APU" revision 1.

The resultant linked output is the superset of all requirements, so the linked output is also "powerpc:e500".

This is because "ppc_exc_initialize.c" includes instructions for different targets that it avoids at run time.

These code lines cause the ".o" to be "powerpc:e500":

ppc_mtivor(32, ppc_exc_vector_address(ASM_E500_SPE_UNAVAILABLE_VECTOR, vector_base));
ppc_mtivor(33, ppc_exc_vector_address(ASM_E500_EMB_FP_DATA_VECTOR, vector_base));
ppc_mtivor(34, ppc_exc_vector_address(ASM_E500_EMB_FP_ROUND_VECTOR, vector_base));

This line causes the ".o" to be "powerpc:titan" (if the above E500 lines are removed):

ppc_mtivor(35, ppc_exc_vector_address(ASM_E500_PERFMON_VECTOR, vector_base));

I "#ifdef'd" them out to get it to "work" but unless someone can figure out how to get rid of that section in the output "ppc_exc_initialize.c" needs to be changed to be conditionally compiled.

If no one has any good ideas I'll open a bug with this.

Peter
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Peter Dufault
HD Associates, Inc.      Software and System Engineering