ldlabs.org – Blog

OMG I’ve deleted a system directory! How do I recover it?

Ok, a little introduction first. I was working on an uninstall target of a Makefile for a system library. For a very unlucky case (or maybe for my stupidity) I’ve deleted (fortunately not all) my /usr directory

And now?

As I said before not every files and binaries were deleted because I realized quickly what I was doing and I pressed ctrl-c to stop it before it was late.

Let’s start with the trick.
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How to automatically execute a VIM command only for some file types

I want to set the maximum line length to a certain value, only for tex files.

VIM has a command to force line length. It’s:

set tw=120

To automatically execute this command only for tex files, you have to edit your vimrc file (~/.vimrc or /etc/vim/vimrc) adding the following lines:

if has("autocmd")
autocmd BufRead,BufNewFile *.tex set tw=120
endif

Now VIM will execute this command every time that you will open a tex file.

Read and write RAM physical addresses from Linux user space

Ok, this is another trick I learned working on my project.

I’ve a QEMU arm machine and a simulation outside them. QEMU shares his RAM (in the future I’ll write about this) with the simulator so I want to unlock the simulation (that is waiting for a 1 at the address 0x0FF8000) writing the specified value on that address using an application in user space inside the VM.

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C++ library in a C application

This is the second part of the integration of a SystemC module into Qemu. SystemC is C++ so I’ve had lots of problems trying to link my library (that is a multiprocessor simulator written in SystemC) with Qemu, because this is written in pure C. Read the rest of this entry »

New features in Virtualbricks

After an entire day of working, now Virtualbricks is able to manager remote virtual machines.

You can configure these machines using a local instance of the software. All the features work on a remote machine except for the interconnections between the bricks. Image disks must be located in the same subdirectory and must have the same name. For example if we want to use a disk disk1.qcow2 and your image directory is /home/noob/VM, another image file called disk1.qcow2 must be in the /root/VM directory.

We are still working on other new features and, most important, we are working to remote networks configuration.

Download source from launchpad and try the software, and please report every bug that you find or additional feature that you want.