#### 21.3.7 PowerPC Embedded

gdb supports using the DVC (Data Value Compare) register to implement in hardware simple hardware watchpoint conditions of the form:

         (gdb) watch ADDRESS|VARIABLE \
           if  ADDRESS|VARIABLE == CONSTANT EXPRESSION

The DVC register will be automatically used whenever gdb detects such pattern in a condition expression. This feature is available in native gdb running on a Linux kernel version 2.6.34 or newer.

gdb provides the following PowerPC-specific commands:

`set powerpc soft-float`
`show powerpc soft-float`
  Force gdb to use (or not use) a software floating point calling convention. By default, gdb selects the calling convention based on the selected architecture and the provided executable file.
`set powerpc vector-abi`
`show powerpc vector-abi`
  Force gdb to use the specified calling convention for vector arguments and return values. The valid options are ‘`auto`’; ‘`generic`’, to avoid vector registers even if they are present; ‘`altivec`’, to use AltiVec registers; and ‘`spe`’ to use SPE registers. By default, gdb selects the calling convention based on the selected architecture and the provided executable file.

`target dink32` dev
  DINK32 ROM monitor.

`target ppcbug` dev
`target ppcbug1` dev
  PPCBUG ROM monitor for PowerPC.

`target sds` dev
  SDS monitor, running on a PowerPC board (such as Motorola's ADS).

The following commands specific to the SDS protocol are supported by gdb:

`set sdstimeout` nsec
  Set the timeout for SDS protocol reads to be nsec seconds. The default is 2 seconds.
`show sdstimeout`
  Show the current value of the SDS timeout.
`sds` command
  Send the specified command string to the SDS monitor.