Red Hat ENTERPRISE LINUX 4 - DEVELOPER TOOLS GUIDE, Manual

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180 Chapter 20. Configuration-Specific Information
time
Execution time in 60ths of a second.
You can refer to these values in gdb expressions with the usual conventions; for example,
b fputc
if $cycles
L
5000
sets a conditional breakpoint that suspends only after at least 5000 simulated
clock ticks.
20.4. Architectures
This section describes characteristics of architectures that affect all uses of gdb with the architecture,
both native and cross.
20.4.1. A29K
set rstack_high_address
address
On AMD 29000 family processors, registers are saved in a separate register stack . There is no
way for gdb to determine the extent of this stack. Normally, gdb just assumes that the stack
is "large enough". This may result in gdb referencing memory locations that do not exist. If
necessary, you can get around this problem by specifying the ending address of the register stack
with the
set rstack_high_address
command. The argument should be an address, which
you probably want to precede with
0x
to specify in hexadecimal.
show rstack_high_address
Display the current limit of the register stack, on AMD 29000 family processors.
20.4.2. Alpha
See the following section.
20.4.3. MIPS
Alpha- and MIPS-based computers use an unusual stack frame, which sometimes requires gdb to
search backward in the object code to find the beginning of a function.
To improve response time (especially for embedded applications, where gdb may be restricted to a
slow serial line for this search) you may want to limit the size of this search, using one of these
commands:
set heuristic-fence-post
limit
Restrict gdb to examining at most
limit
bytes in its search for the beginning of a function. A
value of
0
(the default) means there is no limit. However, except for
0
, the larger the limit the
more bytes
heuristic-fence-post
must search and therefore the longer it takes to run.
show heuristic-fence-post
Display the current limit.
These commands are available only when gdb is configured for debugging programs on Alpha or
MIPS processors.