Showing headlines posted by gus3

Bash provides some interesting built-in specifiers for the prompt strings PS1. Some of them are static, like ‘a’ for ‘alert’ (Ctrl-G, the bell, beep, or visible flash), or ‘n’ or r’ for newline or carriage return. Some specifiers are set during Bash’s startup, like ‘h’ for the hostname, or ‘u’ for the username; these don’t change during any particular shell session. Some are more dynamic,

A project in building a Free computer, using Free tools for both the OS and the hardware, turning an FPGA into a SoC with networking, video, storage, and PCIe. And it's self-hosting, in Linux!

You can create a basic computer animation, using Linux on your desktop, or even on your Raspberry Pi, using a short, well-crafted shell script.

Sometimes, we get ideas we wish we’d thought of sooner. A couple months ago, I got this one: break to the debugger from the source code. (Not specifically Linux, just a cool idea I had.)

Nearly 12 years after it was filed, a lawsuit against IBM Corp. that riled the open-source computer code community is back on the federal court docket in Utah. (No, this isn't an early April Fool's joke. Would that it were.)

One of the drawbacks of a Raspberry Pi is its lack of an on-board clock. After a reboot, its clock is set to midnight, New Year’s Day, 1970 UTC, the beginning of the Unix epoch, and then the kernel boots. However, it is possible to get the current time early in the boot process, with one condition: an NFS root filesystem.

Version 14.1 of Slackware, the oldest Linux distribution still in development, has been officially released.

The stated purpose of the Raspberry Pi is to provide a simple, inexpensive platform for experimentation. For myself, the US$35 (plus shipping, tariffs, and all that) has paid off in spades, giving me the opportunity to attain that Holy Grail of Linux programming: writing a kernel module.

A fixed-rate timer is not part of the ARM specification, but most ARM-based SoC’s have such a timer. The Raspberry Pi is no exception. However, reading its timer in Linux takes a Unix hacker’s understanding.

Turning syslog entry timestamps into human-readable, localized dates and times.

This guide will explain how to rebuild core glibc libraries to use the greater capability of the Raspberry Pi’s on-board ARM 1176JZF-S CPU. The process is not terribly involved, but using NFS for the build space took 8-1/2 hours, even with the CPU overclocked to 900 MHz.

Also, check out the previous article, not particularly Linux, but interesting to techies. - gus3

In my previous article, I showed how combining two instructions into one can speed up a very small countdown loop. In this article, I’ll demonstrate how a single non-optimizing compiler option can have an even greater impact on performance.

How much difference can a single instruction make? On the Raspberry Pi, it can make a difference of 14%, demonstrable without any expensive digital testing equipment.

(Not strictly Linux/FOSS, but shows testing with a DIY philosophy.)

Three months on, my Raspberry Pi is still proving a delight. I have settled on the Raspbian distribution as my tinkerer’s habitat, giving me access to the floating-point unit in the glibc libraries (especially libm.so). However, being mostly uninitiated in Debian administration, I have spent some time learning “the Debian way” of doing things. This article will therefore be a shameless hodge-podge of Raspbian review and Debian ignorance, plus a handy (for me) trick at the end.

Thanks to caitlyn for prodding me to do this. - gus3

Even if the Raspberry Pi is under-powered for desktop work, I have only high regard for the stated goal of the design: an affordable platform for the next generation of hardware and software designers. Considering that the higher-end model is a mere US$35 (plus shipping, handling, and tariffs), the actual bang-for-the-buck is amazing.

My tiny new Raspberry Pi arrived last month, bringing with it a lot of hoopla and renewed enthusiasm for computing. Now that my first task of getting Slackware ARM installed to it, and configuring it to run "headless" (network only, no video or keyboard connected), it’s time to turn my attention to some hardware hacking. I decided to try out some basic cooling systems for it, to see if they make any appreciable difference in the RPi performance.

The computing world lost a luminary this past Sunday. Jack Tramiel passed away at age 83. As founder and long-time head of Commodore Business Machines, he spearheaded computing "for the masses, not the classes." His Commodore VIC-20 and Commodore 64 systems were eminently hackable, to the point that full-speed emulators were available in the mid-1990's. And I have a personal story to tell about him.

A new year, and Linux gets a new major kernel version. It’s time for a new filesystem test!

Connecting a few dots from Download.com to earlier (false) accusations of copyright violations.

First Jobs, then Ritchie, and now McCarthy. This has been a sad month.