• Journal of the Korea Society of Computer and Information
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• v.16 no.5
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• pp.23-31
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• 2011

Improving system boot time has become one of the most important issues in the system software arena. As Linux is widely used in the embedded system environment, extensive research has been conducted in order to mitigate Linux boot time delay. In this respect, this paper mainly focuses on the Hibernation-based boot mechanism, which is the boot mechanism based on Hibernation, as an alternative to the conventional boot sequence. The contributions of this work are as follows. First, we implement the Hibernation-based boot mechanism on a real embedded Linux system and describe the implementation details. Second, we observe the Hibernation-based boot procedures so that we can investigate the possibility whether the boot mechanism has room for improvement in terms of the boot time. Through the in-depth observation and analysis based on the real implementation, we anticipate that the Hibernation-based boot mechanism which adopts various optimization methods can provide maximum of 3.1 times faster booting performance compared to the conventional way.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.12
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• pp.618-629
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• 2007

In this paper, we propose an effective memory test environment, called a virtualized kernel, for 64bit multi-core computing environments. The term of effectiveness means that we can test all of the physical memory space, even the memory space occupied by the kernel itself, without rebooting. To obtain this capability, our virtualized kernel provides four mechanisms. The first is direct accessing to physical memory both in kernel and user mode, which allows applying various test patterns to any place of physical memory. The second is making kernel virtualized so that we can run two or more kernel image at the different location of physical memory. The third is isolating memory space used by different instances of virtualized kernel. The final is kernel hibernation, which enables the context switch between kernels. We have implemented the proposed virtualized kernel by modifying the latest Linux kernel 2.6.18 running on Intel Xeon system that has two 64bit dual-core CPUs with hyper-threading technology and 2GB main memory. Experimental results have shown that the two instances of virtualized kernel run at the different location of physical memory and the kernel hibernation works well as we have designed. As the results, the every place of physical memory can be tested without rebooting.