This would be more appropriate in the Linux or general board if a mod wants to move it. Since you're new to GDB I wont bust your balls too bad, but seriously, did you even try to figure this out on your own? I'm guessing no:
Code:
(gdb) help
List of classes of commands:
aliases -- Aliases of other commands
breakpoints -- Making program stop at certain points
data -- Examining data
files -- Specifying and examining files
internals -- Maintenance commands
obscure -- Obscure features
running -- Running the program
stack -- Examining the stack
status -- Status inquiries
support -- Support facilities
tracepoints -- Tracing of program execution without stopping the program
user-defined -- User-defined commands
Type "help" followed by a class name for a list of commands in that class.
Type "help all" for the list of all commands.
Type "help" followed by command name for full documentation.
Type "apropos word" to search for commands related to "word".
Command name abbreviations are allowed if unambiguous.
(gdb) help data
Examining data.
List of commands:
append -- Append target code/data to a local file
append binary -- Append target code/data to a raw binary file
append binary memory -- Append contents of memory to a raw binary file
append binary value -- Append the value of an expression to a raw binary file
append memory -- Append contents of memory to a raw binary file
append value -- Append the value of an expression to a raw binary file
call -- Call a function in the program
disassemble -- Disassemble a specified section of memory
display -- Print value of expression EXP each time the program stops
dump -- Dump target code/data to a local file
dump binary -- Write target code/data to a raw binary file
dump binary memory -- Write contents of memory to a raw binary file
dump binary value -- Write the value of an expression to a raw binary file
dump ihex -- Write target code/data to an intel hex file
dump ihex memory -- Write contents of memory to an ihex file
dump ihex value -- Write the value of an expression to an ihex file
dump memory -- Write contents of memory to a raw binary file
dump srec -- Write target code/data to an srec file
dump srec memory -- Write contents of memory to an srec file
dump srec value -- Write the value of an expression to an srec file
dump tekhex -- Write target code/data to a tekhex file
dump tekhex memory -- Write contents of memory to a tekhex file
dump tekhex value -- Write the value of an expression to a tekhex file
dump value -- Write the value of an expression to a raw binary file
...
(gdb) help support
Support facilities.
List of commands:
apropos -- Search for commands matching a REGEXP
define -- Define a new command name
document -- Document a user-defined command
dont-repeat -- Don't repeat this command
down-silently -- Same as the `down' command
echo -- Print a constant string
help -- Print list of commands
if -- Execute nested commands once IF the conditional expression is non zero
interpreter-exec -- Execute a command in an interpreter
make -- Run the ``make'' program using the rest of the line as arguments
overlay -- Commands for debugging overlays
overlay auto -- Enable automatic overlay debugging
overlay list-overlays -- List mappings of overlay sections
overlay load-target -- Read the overlay mapping state from the target
overlay manual -- Enable overlay debugging
overlay map-overlay -- Assert that an overlay section is mapped
overlay off -- Disable overlay debugging
overlay unmap-overlay -- Assert that an overlay section is unmapped
quit -- Exit gdb
require -- Prefix command for requiring features
require command -- Demand-load a command by name
require function -- Demand-load a function by name
shell -- Execute the rest of the line as a shell command
source -- Read commands from a file named FILE
up-silently -- Same as the `up' command
while -- Execute nested commands WHILE the conditional expression is non zero
That should get you started in the right direction. GDB has pretty decent built-in help, and Google can fill you in with some details and examples. You can't do too much harm by playing around, and you stand to learn quite a bit, so give it a shot.