User manual

Basic debugging features UM0036
200/385 Doc ID 7705 Rev 11
5.18.4 The symbol-file command
symbol-file filename [-readnow ] [ -mapped ]
You can override the GDB two-stage strategy for reading symbol tables by using the
-readnow option with any of the commands that load symbol table information, if you want
to be sure GDB has the entire symbol table available.
If memory-mapped files are available on your system through the mmap system call, you can
use another option, -mapped, to make GDB write the symbols for your program to a
reusable file. Future GDB debugging sessions map in symbol information from this auxiliary
symbol file, rather than spending time reading the symbol table from the executable
program. Using the -mapped option has the same effect as starting GDB with the -mapped
command-line option.
You can use both options together, to make sure the auxiliary symbol file has all the symbol
information for your program.
The auxiliary symbol file for a program called myprog is called myprog.syms. Once this file
exists (providing it is newer than the corresponding executable), GDB always attempts to
use it when you debug myprog; no special options or commands are needed.
The .syms file is specific to the host machine where you run GDB. It holds an exact image of
the internal GDB symbol table. It cannot be shared across multiple host platforms.
5.18.5 The save_memory command
save_memory from_address count filename [format]
Saves the contents of a range of memory to a file.
from_address is the start address of the memory block to save.
count is the size of the memory block to save.
filename is the name of the file to create.
format is the file format extension: *.srec for Motorola Srecord format, *.ihex for Intel
Hexa format (the default format is *.srec).
5.18.6 The help command
help command
GDB contains its own online help facility giving definitions of all GDB commands. To access
it, at the GDB prompt, enter the command help followed by the name of the command you
want usage information on.
cd directory
Set the GDB working directory to directory.
5.19 Limitations and discrepancies
STVD may be subject to limitations or discrepancies (differences between emulation and
actual MCU behavior). This section provides information about General debug limitations
that are common to all debug instruments and the simulator. It also provides information on
where to find out about limitations and discrepancies that are specific to your debug
instrument and your microcontroller.