To generate symbol information for startup, you must recompile both the startup library and the board's startup with debug information.
The general procedure for this is as follows:
To build the startup library with debug information:
# cd bsp_working_dir/src/hardware/startup/lib/target/a.be # make clean # make CCOPTS=-g # cp libstartup.a bsp_working_dir/board_name/install/processor/lib # make install
The above steps recompile the startup library (libstartup.a) with DWARF debug information and copy this library to the install directory, assuming that the BSP is configured to look for this library first in this directory. The make install is optional, and copies libstartup.a to /processor/usr/lib.
To build the board's startup with debugging information:
# cd bsp_working_dir/board_name/src/hardware/startup/boards/board_name/target/be # make clean # make CCOPTS=-g # make install
The above steps generate the file startup-board_name with symbol and debug information. The make install is necessary, and copies startup-board_name into the install directory, bsp_working_dir/board_name/install/processor/boot/sys.
Modify the build file to include the +keeplinked attribute for startup:
# cd bsp_working_dir/board_name/images
Modify the startup line of your buildfile to look like:
[image=0x10000] [virtual=processor,binary +compress] .bootstrap = { [+keeplinked] startup-board_name -vvv -D8250 PATH=/proc/boot procnto-smp-instr -vv }
The +keeplinked option instructs mkifs to generate a symbol file that represents the debug information, positioned by the specified offset in the image filesystem.
To rebuild the image to generate the symbol file:
# cd bsp_working_dir/board_name/images # make clean
Then, if you're using one of the provided .build files:
# make all
otherwise:
# mkifs -v -r ../install myfile.build image
These commands create the symbol file, startup-board_name.sym. You can use the objdump utility to view the ELF information.
To view the symbol information contained in the startup-board_name.sym file:
# objdump -t startup-board_name.sym | less
You can now import the startup-board_name.sym file into a hardware debugger to provide the symbol information required for debugging startup. In addition to the startup-board_name.sym file, the hardware debugger needs the source code listings found in the following directories: