With the source installed and the tools installed, we are ready to start the process of building a custom Linux kernel.  This article covers those tasks that need to be performed prior to configuration. The steps are not difficult, but there are variations between distros of Linux.

» Continue reading “Preparing the Linux Kernel Source”

The tools and there version play a critical role in the building of a kernel. Most tools are required, but a few (such as the graphical packages required for gconfig or xconfig) are optional. Besides having the right tools installed on the system, the tool versions must match those required to build the installed kernel source. The purpose of this article is to minimize the chance of a kernel build failure due to a missing or improper version of a necessary tool.

» Continue reading “Tools for Building the Linux Kernel”

Downloading and installing kernel source is different than other package source files. Every distro of Linux is different, and the instructions are sometimes rather hard to find. This article covers the seven distros that I use. I would cover more, but I would need more machines, and a lot more time and patience.

» Continue reading “Installing Linux Kernel Source”

I lost count of the number of times someone told me I was nuts for wanting to compile a new kernel Why not get a new different distro of Linux that works on a specific machine? What is wrong with the kernel that comes with the distro? In many cases, the default kernel works just fine. Conversely, there are reasons for compiling a new kernel.

» Continue reading “Why Compile a New Kernel?”

The courseware for my Linux Kernel Fundamentals course is now available from ITcourseware at http://bit.ly/bf82sN.

After hours of searching the Web, I have found nothing that really sheds a whole lot of light on the subject of tuning CFS. Most of the pages on the Web refer to CFS as it was in version 2.6.23 of the Linux kernel. Most web pages do not provide accurate information. I really wonder about the system administrator who could not  understand why he was unable create a directory or file in the /proc directory. While I do not know the the best set of values for the tuneable parameters, I can, hopefully,  shed some light on the subject. » Continue reading “Tuning the Linux Kernel’s Completely Fair Scheduler”

The Linux Kernel manages all hardware through device drivers. Furthermore, the kernel operates in its own protected memory space, which is not accessible from user memory space. Hardware device communicate to the Kernel via interrupts and exceptions. User applications communicate to the Kernel via system calls, which actually trigger a CPU exception that interrupts the Kernel. The question becomes, how can we access what the Kernel knows about the hardware from a user space application? What user applications allow us to view this information? » Continue reading “Hardware Management and Linux”

Do you know how many pixels there are to an em? How about an en? What is wrong with pixels? And the big question is, who should dictate the font and font size, the web page designer or the browser user? While there are different opinions regarding these questions, I am going argue for ems  and user control.

» Continue reading “em What?”

This is by no means a new topic, it is just an often ignored topic. It is so easy to fall in the trap of assuming that everybody sees the world exactly as we see it. We tend to forget about the blind and visually impaired, when we design our Web. In so doing, we ignore an important audience.

» Continue reading “Web Accessibility – A Starting Point”

The common misconception is that the shell always searches the PATH variable to find a command. The truth is that the shell may never get to the PATH variable before it has a name match. Before confusing the issue, let’s look at a simple example. If there is an alias that reads which=’whence -a’, and you enter which pwd, the which command is never executed. The shell first finds the alias, and then subsitutes the alias for the command, and starts the search all over. From this, we know that an alias has precedence over the PATH variable. So what is the order of precedence for finding the command?

» Continue reading “Command Order of Precedence”