Updated Sep. 30, 2003 — Real-time Linux vendor FSMLabs reports that it has created a version of Linux that radically speeds up system boot time — to less than 200 milliseconds (ms) from power-up to application code startup. The techniques are processor independent, and boot times of under 100 ms are expected in the future.

“Normally Linux takes a leisurely 5 seconds or more to complete the boot process,” according to FSMLabs CEO Victor Yodaiken. “This is unacceptable to many embedded device makers who need end-users to see little perceptual delay from the moment a device is switched on to the moment it operates,” he added.

Yodaiken said FSMLabs achieved the feat by studying the boot sequence, isolating places where delays occured, and optimizing those routines. He noted that additional optimizations to further reduce boot time are in the works.

“[We] conducted a detailed analysis of where Embedded Linux is actually being delayed,” noted Cort Dougan, FSMLabs director of engineering. “The results of that study have given us a number of targets for future work on reducing boot time well below the current levels. We believe that sub-100 ms is certainly possible.”

Yokaiken contrasts his company's quickboot solution with execute in place (XIP), an alternative method of achieving fast boot speed. According to Yodaiken, XIP results in unacceptably slow execution times and circumvents RAM error detection critical in applications such as satellite launching.

The first FSMLabs product based on its new fast boot technology is an RTLinux developers kit for a single-board computer from Embedded Planet based on IBM's PowerPC 405GP embedded processor. That board can boot in less than 200 ms from flash memory onto a very basic RAMdisk that includes bash, mount, ls, psutils, and GNU libc (not uclibc or diet-libc).

Boot times of 500 ms are achieved with the 405GP based system when, in addition to basic utilities, the following are loaded:

• modutils
• rtl.o – the RTLinux core module, scheduler, timers, and so on
• lnet.o – The real-time Firewire and Ethernet networking module

“The 500ms load is a slightly different measurement. It includes the time from power-on to the time the RTLinux is loaded and a real-time thread is able to start doing DMA transfers. That's why it's 300ms longer,” according to Dougan.

Yodaiken said the new fast boot technology also supports many Intel x86 boards and that FSMLabs plans on moving this technology to other architectures in response to customer demand. Support for XScale processors is nearly ready, he said.

Visitors to Japan's Embedded Systems Expo and Expo in July saw a demonstration of the technology from Innotech and FSMLabs Japan, and the system software is now directly available from FSMLabs.

 
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