Author Archive

Kexec can spawn a
kernel-over-a-kernel without the overhead of boot firmware, while
kdump can reliably collect a crash-dump
using the services of kexec.

Tried of booting a debug kernel? Kprobes can intrude into your kernel code and extract debug information or apply run time medication.

Many Linux subsystems, such as the /dev filesystem, hotplug, module autoload, and microcode download have undergone significant changes with the introduction of the new device model. Learn about udev, sysfs, kobjects, classes, and more.

Interrupt handlers are an integral part of most device drivers. Learn to implement interrupt handlers and bottom halves.

Look at messages generated during kernel boot and explore the internals of the more interesting ones.

Kernel helper interfaces make life easier for developers. Learn about notifier chains, completion functions and error handling aids.

The process filesystem is a window into the mystical innards of the kernel. The seq file interface simplifies the job of process file creators.

The use of standard kernel helper facilities simplifies your code, weeds out redundancies from the kernel, and helps long-term maintenance. And since the helpers are bug-free and optimized, you inherit those benefits for free.

Learn how the kernel views physical memory.

Most embedded devices boot from flash memory and have data resident on flash-based storage. Here’s how to use flash devices while embedding Linux.

The x86 kernel has direct and indirect dependencies on the system BIOS. Here’s a look at some of the guts.

Multiple threads of execution need to be synchronized to avoid data corruption and even system freezes.

The kernel keeps track of the flow of time. It provides services to sleep wait for long periods and busy wait for short periods, can schedule events to run at a future time, and can do periodic work with microsecond precision. Here’s a look at kernel time.

Kernel threads are used to implement background tasks inside the kernel. They are similar to user processes, but live in kernel address space. Here’s how to use them.

Profiling helps find code bottlenecks. Trace tools provide the ability to extract and interpret details about code execution.

Debuggers make kernel internals more transparent. On Linux, they come in different flavors: The Kernel debugger, kdb, the Kernel GNU debugger, kgdb, the GNU debugger, gdb, and JTAG- based debuggers. Learn how to use the former three in this month’s column.

Thanks to plug-and-play devices like PC cards, you can backup gigabytes of data onto a stamp-sized device or enable your laptop with diverse networking technologies.

Technologies like Wi-Fi, GPRS, and miniature storage devices are ubiquitous today as PCMCIA or CF cards. The Linux kernel supports PCMCIA devices on a variety of architectures.

Look at the internals of a line discipline and implement a simple line discipline for a serial touch screen controller.