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TDDB68 Concurrent programming and Operating Systems

FAQ

The purpose of this page is to collect some common problems that students encounter. It is by no means complete, but the ambition is to exend this page with more problems and in time it will hopefully become a valuable resource. If you have something that you think would fit on this page. Please send a mail to mikael.asplund@liu.se with the problem and solution (following the format below).

Emulator-related

Cant exec "qemu"

Problem:

when running the pintos command "pintos --qemu -- -f -q", an error message is produced stating

Can't exec "qemu": No such file or directory at /src/utils/pintos line 877.

command failed

Solution:

Recreate the qemu symbolic link:

ln -s /usr/bin/qemu-system-i386 /src/utils/qemu

Debugging

Using a graphical debugger

Problem:

How to use a graphical debugger?

Solution:

In addition to the gdb-pintos command which provides an interactive but text-based interface, you can also use the graphical frontend ddd. To start ddd you follow all the instructions from lab0 except replacing the line:

pintos-gdb kernel.o

with

ddd --debugger pintos-gdb kernel.o

(As usual you must have setup your path correctly for it to work). The commands to gdb should be provided in the gdb console at the bottom of the ddd window. You can open the source files directly in ddd and set breakpoints by right-clicking in the source panel.


Page responsible: Mikael Asplund
Last updated: 2020-08-21