gdb won't read core file from foreign architecture
I'm trying to read an ARM core file on my Linux desktop, but it seems not to be able to figure out my core file. Is there any way I can instruct gdb what type my core file is?
$ file ~/daemon
./daemon: ELF 32-bit LSB executable, ARM, version 1, dynamically linked (uses shared libs), for GNU/Linux 2.0.0, not stripped
$ file ~/core
./core: ELF 32-bit LSB core file ARM, version 1 (SYSV), SVR4-style, from './daemon -v -v -v -v -e 10 -t foo'
$ gdb-multiarch ~/daemon ~/core
GNU gdb (GDB) 7.5-ubuntu
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from ./daemon...done.
"./core" is not a core dump: File format is ambiguous
(gdb) core-file ~/core
"./core" is not a core dump: File format is ambiguous
The generating platform is armv4, which gdb-multiarch claim to support, according to the "set architecture" list.
EDIT: To clarify, my desktop machine running gdb is "x86_64-linux-gnu", namely an 64-bit Intel Ubuntu box.
Answer
This may help:
$ gdb-multiarch
...
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
(gdb) set gnutarget elf32-littlearm
(gdb) file daemon
...
(gdb) target core core
...
(gdb)