The holy bible of SWEB - Institute of Applied Information Processing ...

2.3. QEMU CHAPTER 2. GDB
The patch file is located at ...sweb/utils/bochs
• Once the source files are patched we can run the configure script. It is recommended
to use an alternative prefix (installation location) to be able to switch
between different bochs versions (e.g. patched not patched version)
$ ./ configure −−enable−gdb−stub −−prefix=/opt/sweb−bochs
• Once the configuration is done, start compiling and installing
$ make
$ sudo make i n s t a l l
Needless to say that you need some default dev packages like gcc to successfully
complete the compile process, in addition you need a package called xorg-dev or
x-window-system-dev on some other systems
• Self - compiling bochs does not replace installing the packages vgabios and
bochsbios
2.3 Qemu
For using the gdb stub from qemu, start it with
$ make qemugdb
2.4 Using GDB
With bochs or qemu started as described before, gdb can connect to it. There is a
make target rungdb which preconfigures GDB and connects to localhost:1234.
$ make rungdb
.
.
.
0x0000fff0 in ?? ( )
You can now set trace and breakpoints .
Enter ’ continue ’ ( or ’ c ’ ) when you ’ re done .
( gdb )
Once bochs or qemu exits you could end GDB and run make rungdb again, but then
all you temporary settings like breakpoints are gone and you have to set them up
again. So there is another way to reconnect GDB to bochs or qemu. Just run the
following from inside GDB and all your breakpoints and other settings remain active.
target remote localhost :1234
From here, gdb can be used as usual, except that it is not necessary to call run, as
the simulation is already started but paused for command input. It can be resumed
using the continue command.
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