Question on attribute save-restore in reg elements (target descriptions).

["Anmol P. Paralkar" <b07584@freescale.com>]

Hello,

  Per Appendix F, Sec. F.2.5 Registers, of the GDB User Manual:

  save-restore

     Whether the register should be preserved across inferior function
     calls; this must be either yes or no. The default is yes, which
     is appropriate for most registers except for some system control
     registers; this is not related to the target's ABI.

  In our target description file, we have a lot of special purpose
  registers about which nothing might be assumed either way, so in
  addition to 'yes' and 'no', can we have an "unspecified" value to
  this attribute, (say, denoted by '?')? In what way does GDB use this
  information?

  PS: Please could you also clarify the term 'inferior function'?

Thank you,
Anmol.