[PATCH] arm reversible : <phase_2_complete>
Tom Tromey
tromey@redhat.com
Thu Apr 28 19:00:00 GMT 2011
>>>>> "Oza" == paawan oza <paawan1982@yahoo.com> writes:
Tom> It seems to me that extract_typed_address or something similar would be
Tom> better.
Oza> 1) are suggesting to use something else than unions ? whatever you have
Oza> described about union is right.
Oza> 2) why could I use extract_typed_address instead of direct assignment ?
extract_typed_address handles endianess and conversion from "array of
bytes" to "host scalar".
Oza> 3) in my understanding cross debug would not affect endianess
Oza> because all the record saving done on target memory and played back
Oza> in target memory. they never get fetched to host machine I think.
Oza> please clarify how would it affect host/target endianness issue ?
Here is a snippet from the patch:
+ GET_REG_VAL (reg_cache, ARM_PC_REGNUM, &u_buf.buf[0]);
[...]
+ start_address = u_buf.s_word - \
+ (4 * (bit (thumb_insn_r->arm_insn, 8) + register_count)) ;
Here, this fetches the raw register bits from the cache, which, IIUC,
are in target order. Then it uses the union to turn this into a scalar,
and does math on the scalar value.
So, if the host and target endianness differ, you will get the wrong
result.
Maybe I am missing something here?
Tom
More information about the Gdb
mailing list