You can use the commands dump, append, and restore to copy data between target memory and a file. The dump and append commands write data to a file, and the restore command reads data from a file back into the inferior's memory. Files may be in binary, Motorola S-record, Intel hex, or Tektronix Hex format; however, gdb can only append to binary files.
Dump the contents of memory from start_addr to end_addr, or the value of expr, to filename in the given format.
The format parameter may be any one of:
Raw binary form.
Intel hex format.
Motorola S-record format.
Tektronix Hex format.
gdb uses the same definitions of these formats as the gnu binary utilities, like objdump and objcopy. If format is omitted, gdb dumps the data in raw binary form.
Append the contents of memory from start_addr to end_addr, or the value of expr, to filename, in raw binary form. (gdb can only append data to files in raw binary form.)
Restore the contents of file filename into memory. The restore command can automatically recognize any known bfd file format, except for raw binary. To restore a raw binary file you must specify the optional keyword binary after the filename.
If bias is non-zero, its value will be added to the addresses contained in the file. Binary files always start at address zero, so they will be restored at address bias. Other bfd files have a built-in location; they will be restored at offset bias from that location.
If start and/or end are non-zero, then only data between file offset start and file offset end will be restored. These offsets are relative to the addresses in the file, before the bias argument is applied.