Endian issues on T4240 Powerpc:e6500
Ed Liversidge
ed@harmonicss.co.uk
Mon May 1 09:43:00 GMT 2017
Hi,
I am trying to get gdb 7.12.1 (build from source tried --target=powerpc64-linux-gdb and --target=powerpc64-elf-gdb), to allow me to remotely debug a T4240 PowerPC target.
When I connect to a bdi3000 emulator, gdb reports the program counter to be 32bit word swapped to the actual program counter, reported by the emulator:
(gdb) target remote 192.168.1.70:2001
(gdb) show architecture
The target architecture is assumed to be powerpc:e6500
(gdb) show endian
The target endianness is set automatically (currently big endian)
(gdb) i r pc
pc 0x801080f8ffffffff 0x801080f8ffffffff
(gdb) x $pc
0x801080f8ffffffff: Cannot access memory at address 0x801080f8ffffffff
T4240#0>info
Target CPU : T4/B4 Thread#0 (e6500)
Core state : halted
Debug entry cause : single step
Current PC : 0xffffffff_801080f8
Current CR : 0x00000000
Current MSR : 0x80000200
Current LR : 0xffffffff_8021bee4
Current CCSRBAR : 0xf_fe000000
As you can see, the BDI reports the PC as 0xffffffff801080f8, and gdb reports it as 0x801080f8ffffffff. I thought perhaps this was a display issue, but the read of the instruction at $pc is also incorrect.
Is this a bug, or am I missing something?
I have also tried the very latest git 8.0, with different results:
(gdb) target remote 192.168.1.70:2001
Remote debugging using 192.168.1.70:2001
warning: No executable has been specified and target does not support
determining executable automatically. Try using the "file" command.
0x7ff7bef0 in ?? ()
(gdb) i r $pc
pc 0x7ff7bef0 0x7ff7bef0
(gdb) show architecture
The target architecture is set automatically (currently rs6000:6000)
(gdb) set architecture powerpc:common64
The target architecture is assumed to be powerpc:common64
Truncated register 51 in remote 'g' packet
(gdb) show architecture
The target architecture is assumed to be powerpc:common64
Truncated register 51 in remote 'g' packet
(gdb) i r $pc
Truncated register 51 in remote 'g' packet
Can anyone help me to get this working?
Thanks in advance for any help,
Ed Liversidge
Director, Harmonic Software Systems Ltd.
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