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Re: assembling output of objdump dissassembly
- From: Nick Clifton <nickc at redhat dot com>
- To: SigmFSK at aol dot com
- Cc: binutils at sourceware dot org
- Date: Thu, 12 Oct 2006 10:13:31 +0100
- Subject: Re: assembling output of objdump dissassembly
- References: <bf6.6dd72b8.325efafc@aol.com>
Hi Arthur,
It appears that the objdump output is quite similar to, but deliberately
different from, the assembly created from compiling a c program with "gcc -S".
Is there a mechanism to convert the objdump disassembly output to an
assemblable form?
Apart from doing this by hand, no.
Or is that a deliberate objdump decision to have the output
different, as my desire is inherently unworkable,
It was a deliberate decision but the motive was to make disassembler's
output be useful to people who want to examine the contents of a binary
file, not to allow re-assembly. To this end, more information is
presented to the user than is needed to just re-assemble the
disassembled output.
as modifying the disassembly
would change all the branch offsets and cause everything to break?
No, the real problem is coping with relocations. The disassembled
output of a file is not just the textual disassembly, but also the
relocations that are associated with that disassembly. You would need
some way to re-install those relocations back into the assembler source,
possibly regenerating local labels as you go. A difficult task.
Cheers
Nick