Re: objdump of binary for micromips.

[Kenneth Johansson <kenneth dot johansson at inteno dot se>]

On 2017-01-11 19:55, Maciej W. Rozycki wrote:
> On Tue, 27 Dec 2016, Kenneth Johansson wrote:
>
> > > you specified the arch as mips, so you'll get mips32.  if you run
> > > `objdump -h`, you'll see a huge list of other arch values.  you
> > > probably want to use something like "mips:micromips".
> > > -mike
> > tanks I did not understand the syntax but it did still not work out. the
> > lauterbach trace32 debug understands the code but objdump gets confused.
>   The `-M mips:micromips' option is only really there for binaries with no
> symbol information available, so that you can manually choose the correct
> disassembly mode, e.g. for the binary or SREC BFD.  If the binary you
> examine does have symbol information, then the ISA mode will be determined
> on a function by function basis according to ISA annotation recorded with
> individual symbols in the symbol table, ignoring any `-M mips:micromips'
> (or `-M mips:16') override.  So either your code is really made of regular
> MIPS instructions or you have got symbol annotation wrong in your binary
> -- which sometimes happens in handcoded assembly that hasn't been written
> correctly (GCC is supposed to get it right for generated code).
>
>   If you think the binary has been or should have been annotated correctly
> and believe this is a toolchain bug, then please provide us with a test
> case and we will investigate.

no this was from a binary blob so no symbols no nothing and turned out 
to be a mix of normal mips32 and mips16 and not micromips as I thought 
it was.

The only way I could read it was to disassemble only small parts at a 
time and then change the flags if it looked to strange.

But one thing I do think is a "bug" or at least a missing feature is 
that there seems to be no way to make loads and stores that is relative 
to a register display the offset in hex now it only uses decimal and 
that is very inconvenient.

 890372a:       f401 da88       sw      a0,3080(v0)

would have been much easier to read/grep if it would have been
 890372a:       f401 da88       sw      a0,0xc08(v0)

as it happens that most(all) documentation for hardware uses hex numbers 
for hardware register addresses.