Info Catalog gdb: OpenRISC 1000 gdb: Embedded Processors gdb: AVR

gdb: PowerPC Embedded

 
 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 when GDB detects such
 pattern in a condition expression, and the created watchpoint uses one
 debug register (either the 'exact-watchpoints' option is on and the
 variable is scalar, or the variable has a length of one byte).  This
 feature is available in native GDB running on a Linux kernel version
 2.6.34 or newer.
 
    When running on PowerPC embedded processors, GDB automatically uses
 ranged hardware watchpoints, unless the 'exact-watchpoints' option is
 on, in which case watchpoints using only one debug register are created
 when watching variables of scalar types.
 
    You can create an artificial array to watch an arbitrary memory
 region using one of the following commands (Expressions):
 
      (gdb) watch *((char *) ADDRESS)@LENGTH
      (gdb) watch {char[LENGTH]} ADDRESS
 
    PowerPC embedded processors support masked watchpoints.  See the
 discussion about the 'mask' argument in Set Watchpoints.
 
    PowerPC embedded processors support hardware accelerated "ranged
 breakpoints".  A ranged breakpoint stops execution of the inferior
 whenever it executes an instruction at any address within the range it
 specifies.  To set a ranged breakpoint in GDB, use the 'break-range'
 command.
 
    GDB provides the following PowerPC-specific commands:
 
 'break-range START-LOCATION, END-LOCATION'
      Set a breakpoint for an address range given by START-LOCATION and
      END-LOCATION, which can specify a function name, a line number, an
      offset of lines from the current line or from the start location,
      or an address of an instruction (see Specify Location, for
      a list of all the possible ways to specify a LOCATION.)  The
      breakpoint will stop execution of the inferior whenever it executes
      an instruction at any address within the specified range,
      (including START-LOCATION and END-LOCATION.)
 
 '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.
 
 'set powerpc exact-watchpoints'
 'show powerpc exact-watchpoints'
      Allow GDB to use only one debug register when watching a variable
      of scalar type, thus assuming that the variable is accessed through
      the address of its first byte.
 

Info Catalog gdb: OpenRISC 1000 gdb: Embedded Processors gdb: AVR