• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10c
• /
• pp.106-108
• /
• 2001

본 논문에서는 임베디드 자바 가상 대신(Embedded Java Virtual Machine)과 임베디드 실시간 운영체제(Embedded Real-Time Operating System)인 iRTOS$^{TM}$를 통합하기 위한, 설계 및 구현 내용을 기술하고자 한다. 인터넷 가전을 위한 실시간 운영체제 기반의 통합 환경은 각 가정에서 사용하는 정보 가전 제품들을 인터넷에 연결하여 사용함으로써 사용자에게 좀 더 효율적이며. 편리한 서비스를 제공할 수 있다. 또한 어떠한 플랫폼에도 구애 받지 않고 동작 할 수 있는 자바를 실행하기 위한 내장형 JVM 의 추가로, 기존의 플랫폼 의존적인 방법을 벗어나 어떠한 가전 기기상해서도 자바로 개발된 모든 기능들을 동일한 조건으로 동작시킬 수 있다는 장점을 갖는다. 본 논문에서는 통합 설계서의 세부 내용과 통합 방법에 대해 언급하고자 한다.

• Proceedings of the IEEK Conference
• /
• 2003.11b
• /
• pp.19-22
• /
• 2003

Class area is a portion of memory where the constants, fields, and codes of the classes loaded into the Java virtual machine are kept. Knowing the site of the class area is very important especially for embedded Java system with limited memory resources. This paper induces a formula which makes it possible estimate the size of the area. The formula needs some constant values specific to target JVM implementation. We also show that these values can be found using some simple probe classes. An experimental result is included in this paper to confirm the correctness of our approach.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10a
• /
• pp.250-252
• /
• 2003

현재 무선단말기를 비롯한 많은 내장형 기기에서 자바 플랫폼을 채택하고 있다. 내장형 기기는 제공되는 메모리 용량의 제약으로 인하여 J2ME 플랫폼을 주로 사용하고 있다. J2ME 플랫폼은 CDC와 CLDC 컨피큐레이션으로 나뉘며. CDC는 JAVA 어플리케이션의 수행에 있어서 JVM보다 적은 동적 수행 메모리를 요구하는 CVM을 채택하고 있다. CDC는 CLDC에 비하여 메모리의 제약이 상대적으로 적은 셋탑박스 등과 같은 내장형 기기에서 주로 사용된다. 본 논문에서는 J2ME 플랫폼의 VM중에 하나인 CVM상에서 어플리케이션 수행에 따른 Generational GC의 특성에 대하여 알아본다. 특히 오브젝트의 life time, 가비지 컬렉션 주기 pause time 및 young generation의 크기에 따른 동작 특성을 중점적으로 고찰한다.

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.812-816
• /
• 2007

Having been speedy development of the IT industry, devices such as set-top box and smart phone are used in the broad filed. Because Java has merits that are platform independency, security and mobility, that is important software platform to offer stable services in the small device. This needs JVM(Java Virtual Machine) to execute Java application in the small device. CVM(Classic Virtual Machine) which is the kind of JVM is designed for embedded device to have limited resources. In this paper, CVM which is defined by CDC has designed and implemented on the Real-Time Operating System, UbiFOS$^{TM}$.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05b
• /
• pp.983-986
• /
• 2003

마이크로소프트사는 .NET 플랫폼을 개발하면서 C/C++의 강력함과 자바나 비주얼 베이직의 높은 생산성을 매우 효과적으로 결합한 프로피래밍 언어인 C#을 만들었다. C#은 컴파일 과정을 거치며 자바의 바이트 코드와 같은 중간 언어인 MSIL 코드를 갖는 파일을 출력하게 되는데, C# 이외에도 모든 .NET 언어들은 컴파일과정을 거치면서 MSIL 코드를 얻기 때문에 여러 .NET 언어들을 이용해서 하나의 응용 프로그램을 만들 수 있다. 썬 마이크로시스템즈사의 자바는 현재 가장 널리 사용되는 프로그래밍 언어 중 하나이며, 컴파일러에 의해 플랫폼에 독립적인 바이트 코드를 바이너리 형태로 가지고 있는 클래스 파일을 생성하면 JVM에 의해 운영체제와 하드웨어에 독립적으로 수행이 가능한 차세대 언어이다. 본 논문에서는 임베디드 시스템에서의 적용을 위해 C#을 컴파일 하여 나오는 중간 언어 형태인 MSIL 코드를 자바의 중간언어의 한 종류인 Oolong 코드로 변환해 줌으로서 C#으로 구현된 프로그램이 자바 플랫폼에서 JVM에 의해 실행되도록 하는 MSIL-to-Oolong 번역기 시스템 구현하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.1
• /
• pp.486-492
• /
• 2011

In this paper we analyzed performance of Andriod's Davik virtual machine(VM) using standard benchmark and compared the result with the embedded Java virtual machine. We used a well known benchmark suit named SPECJVM for the measurement. For the fair comparison, Sun Java embedded JVM is ported and the same benchmark is ported on it. The Odriod smartphone hardware platform is used as the target hardware. We have added a Just-In-Time compiler to Dalvik, which is not supported in the recent Android release, and measured performance improvement. The experiment result show that Dalvik achieved 15% and Dalvik with JIT shows 63% of the Sun's JVM performance.

• The KIPS Transactions:PartA
• /
• v.14A no.3 s.107
• /
• pp.173-184
• /
• 2007

Garbage collection in the Java virtual machine is a core function that relieves application programmers of difficulties related to memory management. In this paper, we evaluate and analyze the performance of GenGC and GenRGC, garbage collectors for embedded Java virtual machines. For performance evaluation, we employ CVM, a real embedded Java virtual machine developed by Sun Microsystems, Inc., as a platform and also use a widely-used SpecJVM98 as a set of benchmark programs. To compare the performance of GenGC and GenRGC, we first evaluate the time of garbage collection and the delay time caused by garbage collection. Second, for more detailed performance analysis of GenRGC, we evaluate the time of garbage collection and the delay time caused by garbage collection while changing the sizes of a block and a frame. Third, we analyze the size of storage space required for performing GenRGC, and show GenRGC to be suitable for embedded environment with a limited mont of memory. Since CVM is the most representative one of embedded Java virtual machines, this performance study is quite meaningful in that we can predict the performance of garbage collectors in real application environments more accurately.

• Journal of Korea Multimedia Society
• /
• v.8 no.9
• /
• pp.1282-1291
• /
• 2005

This paper presents the EVM(Embedded Virtual Machine) which enables the execution of dynamic applications loaded in the embedded systems such as Mobile Devices(mobile phone, PDA), Set-Top Box, and Digital TV using downloading techniques. To accomplish this goal, we defined a SIL-(Standard Intermediate Language) code, and implemented a Bytecode-to-SIL translator which enables the execution of programs written in java language in the EVM platform without JVM, and a MSIL--to-SIL- translator which enables for programs written in .NET language to be executed in the EVM platform without .NET platform. Also, we developed a EFF(Executable File Format) builder as an assembler which translates SIL codes into an executable file, *.evm, and implemented the EVM which reads the *.evm file and executes it. The virtual machine for embedded systems developed in this paper is the software technologies that enable the execution of applications or contents without changes to when the platforms change. In fact, the virtual machine suggested here is not only usable as a standard model for existing virtual machines but also aid in more efficient execution of applications loaded in the embedded systems such as Mobile Devices, Digital TV, and Set-Top Box.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.42 no.4 s.304
• /
• pp.11-16
• /
• 2005

Class area is a portion of memory where the constants, fields, and codes of the classes loaded into the Java virtual machine are kept. Knowing the size of the class area is very important especially for embedded Java system with limited memory resources. This paper induces a formula which makes it possible estimate the size of the area. The formula needs some constant values specific to target JVM implementation. We also show that these values can be found using some simple probe classes. An experimental result is included in this paper to confirm the correctness of our approach.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.5
• /
• pp.1058-1067
• /
• 2004

Java virtual machine provides code compactness, simple execution engines, and platform-independence which are important features for small devices such as mobile or embedded device, but it has a big problem, such as low throughput due to stack-oriented operation. In this paper hardware lava accelerator targeted for mobile or embedded application is designed to eliminate the slow speed problem of lava virtual machine. The designed lava accelerator can execute 81 instructions of Java virtual machine(JVM)'s opcodes and be used as Java coprocessor of conventional 32-bit RISC processor with efficient coprocessor interface and instruction buffer. It consists of about 14,300 gates and its maximum operating frequency is about 50 Mhz under 0.35um CMOS technology.