[Linux-Xtensa] Re: [patch 0/8] xtensa: s6000 & s6105 - Git Repo Pulled; will try to merge early next week and get back to ya.

linux-xtensa at linux-xtensa.org linux-xtensa at linux-xtensa.org
Tue Mar 31 07:48:38 PDT 2009


I see there has been no answer to this question of yours:

On 03/26/2009 10:03 AM, Piet Delaney wrote:
> I didn't understand the need for the ptrace change, have a pointer to
> Blackfin reference that might enlighten me?

It's difficult to find the source of this change. I think it originates from
m68knommu but it can also be found on ARM, Blackfin, H8/300, and, in a slightly
modified form, on FR-V. Basically all nommu architectures need it to debug
applications.

On MMU architectures an application is always loaded at the virtual address
recorded in the file header. Architectures without MMU can't do this and
relocate the application after loading it to an available area. When a debugger,
i.e. gdb, wants to debug an application on a remote host, it has access to the
binary with its symbols but is given (from gdbserver) addresses inside the
relocated application. To allow gdb to relocate the symbols, it needs to be
passed the three values mm->start_code, mm->end_code, and mm->start_data.

The code in gdbserver to read and pass on these values has been added with this
patch: http://sourceware.org/ml/gdb/2006-05/msg00078.html

I hope this helps understand the change.

Best regards,

  Daniel

-- 
Dipl.-Math. Daniel Glöckner, emlix GmbH, http://www.emlix.com
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