Anonymous user
QEMU: Difference between revisions
Jump to navigation
Jump to search
no edit summary
| [unchecked revision] | [unchecked revision] |
m (Add link to QEMU_fw_cfg article) |
No edit summary |
||
Line 2:
==Features==
*
*
*
*
▲* provides native [[GDB]] support and you can attach it to [[GDB]]/[[DDD]] by adding the "-s -S" switches to the command line and from the [[GDB]] window start the debugging session with "target remote :1234" if QEMU is waiting on local port 1234.
▲* support [[VBE]] 2.0. This can be checked if you use the [[GRUB]] command line and type vbeprobe. The test returns:
Line 74 ⟶ 73:
==Supported Architectures==
* [[:Category:X86|x86]]
* [[X86-64|x86_64]]
* [[:Category:ARM|ARM]]
* [[ARM64]]
* [[LatticeMico32]]
* [[Motorola 68000]]
* [[MicroBlaze]]
* [[MIPS]]
* [[MIPS64]]
* [[Moxie]]
* [[PowerPC]]
* [[PowerPC64]]
* [[RISC-V]]
* [[IBM System/390]]
* [[SuperH]]
* [[:Category:Sparc|SPARC]]
* [[SPARC64]]
* [[TriCore]]
* [[Unicore]]
* [[Xtensa]]
==Supported Devices==
Line 112 ⟶ 111:
QEMU is easy to use, it does not have a configuration script like Bochs. To use QEMU with your OS,
<source lang="bash">
</source>
Or, if you use UNIX,
<source lang="bash">
</source>
The -L tells QEMU where to find its BIOS images, which is not necessary in a standard unix installation. The -m tells how many megabytes of memory to use; the default is 128
Line 134 ⟶ 137:
When you hit CTRL-ALT-2 you are placed in the QEMU monitor which is a command-line for querying information about the system while it is running. It does not quite act as a debugger, but, used in combination with GDB-stub, you can get pretty much all the functionality you will need. In Unix hosts, you can even redirect this monitor interface to the standard output using the
<source lang="bash">
</source>
command-line option. Some useful commands:
; xp : eXamine Physical memory. Much like GDB's <tt>x</tt> command, but with no address translation.
Line 144 ⟶ 149:
===GDB-stub===
{{FirstPerson}}
When you supply the <tt>-s</tt> command line option, QEMU will listen on port localhost:1234 for a connection by GDB. If you also supply the <tt>-S</tt> command line option, then QEMU will start as if you set a breakpoint at time zero, and you will need to use the GDB command "continue" to actually begin the simulation.
Line 149 ⟶ 155:
For convenience, I put a file called <tt>.gdbinit</tt> in the current working directory which automatically runs certain commands when you start GDB without the <tt>-n</tt> option. For example:
<source lang="gdb">
</source>
will load into GDB your kernel and then connect to QEMU. Be sure to compile your kernel with the GCC option <tt>-g</tt> for debugging symbols. (If you find that the debugger can't find local variables, try using the <tt>-fno-omit-frame-pointer</tt> option when compiling, or disable optimizations.) Now you may debug your kernel as a C program.
Line 158 ⟶ 166:
Most of the QEMU source code has commented lines of the form:
<source lang="c">
</source>
If you are willing to edit and recompile QEMU, then you can get a good deal of debugging info output to stdout by uncommenting those lines at the top of the files that implement the pieces of the simulation you need more info about.
| |||