Re: Fwd: Re: [patch] Add support for ARMv7M devices.

[Jonathan Larmour <jifl@eCosCentric.com>]

On 09/03/12 15:38, Yao Qi wrote:
> On 03/09/2012 12:24 PM, Jonathan Larmour wrote:
>> -		tdesc = tdesc_arm_with_m;
>> +		is_m = 1;
> 
> `tdesc' is used later in the function,
> 
>   /* Check any target description for validity.  */
>   if (tdesc_has_registers (tdesc))
> 
> Is it correct to skip updating `tdesc'?

Yes we do not want that condition to match. We want the tdesc to still be
undetermined by the point of the 'if' test if this is Cortex-M. The code
prior to this change only set tdesc because it thought it knew exactly
what register set to use by that point.

But you have made me think of one improvement: we should probably not call
register_remote_g_packet_guess() if tdesc_has_registers (tdesc) - because
if someone has directly supplied a target description, we should solely
use that, and avoid any guessing. This would be true for both my and
Pedro's patch.

That's trivial to handle though, e.g. for Pedro's patch, just replace the
call with:

  if (!tdesc_has_registers (tdesc))
    arm_register_g_packet_guesses (gdbarch);

Jifl
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