• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.167-172
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• 2008

The purpose of the project was intended to show an application method of RTOS to PICmicro with limited resources with several tasks controlling the peripheral devices. The application runs on the designed PIC16F87x evaluation board with a bootloader burned so the application program can be easily downloaded using the serial communication without using the ROM writer. Thus, it would also be a good example to use for instructional or tutorial purposes for PICmicro education. The demo shows a useful examples who wish to use the real time operation system in their own projects.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.6
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• pp.335-343
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• 2015

As the usage of mobile devices becomes diverse, a number of attacks on Android also have increased. Among the attacks, Android can be compromised by flashing a new image of compromised Android Linux. In order to solve this problem, we propose SeBo (Secure Boot System) which prevents compromised Android Linux by guaranteeing secure boot environment for mobile devices based on ARM TrustZone architecture. SeBo checks the hash value of the Android Linux image before the Android Linux executes. SeBo detects all the attacks within 5 seconds. Moreover, since SeBo only trusts the Secure Bootloader from Secure World, SeBo can reduce the additional overhead of checking the Normal Bootloader from Normal World.

• KIISE Transactions on Computing Practices
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• v.23 no.8
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• pp.504-509
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• 2017

Preserving the integrity of the booting process is important. Recent rootkit attacks and subverting OS attacks prove that any post-OS security mechanism can be easily circumvented if the booting process is not properly controlled. Using an actual case as an example, the hacker of the Se-jong government office simply bypassed the user's password authentication by compromising the normal booting process. This paper analyzes existing pre-OS protection using secure boot and measured boot, and proposes another bootloader that overcomes the limitations. The proposed bootloader not only guarantees the integrity of all the pre-OS binaries, bootloaders, and kernel, it also makes explicit records of integrity in the booting process to the external TPM device, so that we can track modifications of BIOS configurations or unintended booting process modifications.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.6
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• pp.594-598
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• 2008

In this paper we propose a fast booting technique based on Improved snapshot boot in embedded Linux, widely adopted in personal devices such as PDA and mobile phones. The existing Snapshot boot technique tries to create a snapshot image at the time of suspend, and later load the entire snapshot image into the system memory at the predefined location with the help of a bootloader at the time of resume. Since a bootloader has to copy the entire snapshot image into the predefined memory to resume the previous suspended computing state, a little bit long time is required to resume. Improved snapshot boot does not create a snapshot image consisting of whole memory pages at the time of suspend, thus resulting in smaller snapshot image than the existing snapshot boot. The remaining pages are in the swap area. The resulting smaller sized snapshot image enables much faster booting latency. Through the experiment, we can see the booting latency is reduced almost 30% with suspend image of 2982 pages. This result depends on the amount of swap-out pages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.96-101
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• 2021

Arduino is one of the open source microcontroller projects, and Arduino boards using AVR microcontrollers are commonly used. In general, AVR microcontrollers use ISP (In System Programming) upload, but in Arduino, serial upload through a bootloader is basically used, and a dedicated microcontroller is built into the board for this purpose. In order to use the ISP upload in Arduino, a dedicated upload device is required, which is not included in the Arduino board. In this paper, we propose a unified programmer that can handle ISP upload and serial upload through one dedicated microcontroller, and show that ISP and serial upload are possible using the unified programmer. In addition, the proposed unified programmer works as a USB-serial converter, supports serial communication with a computer, and it is also possible to burn the Arduino bootloader. All operations of the unified programmer can be confirmed through the experimental results.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.931-933
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• 2005

Windows CE는 Microsoft사의 Windows 운영체제 가운데서 가장 작은 운영체제로서 일반 데스크톱 Windows 커널을 수용할 수 없는 소형/임베디드 장비에서 주로 사용되어진다. 현재 Windows CE에서 사용되고 있는 부트로더로는 E-boot(Ethernet bootloader)가 있으며 RAM 이미지와 플래시 이미지 다운로드 기능을 제공한다. E-boot의 문제점으로는 플래시 메모리상에서 부팅을 수행하기 때문에 NOR 타입의 플래시만을 지원하여, 컴팩트 플래시와 같은 NAND 타입의 플래시 지원하지 않는다. 이는 OS Binary 이미지의 용량이 NOR 플래시를 초과할 경우에 수행이 불가능하다는 문제를 발생시킨다. 따라서 본 논문에서는 기존의 E-boot를 수정하여 NDR 플래시보다 상대적으로 가격이 저렴하고 휴대성이 좋은 컴팩트 플래시 메모리를 이용하여 부팅이 가능한 부트로더를 구현한다. 또한 컴팩트 플래시 지원을 위한 새로운 읽기/쓰기 메카니즘을 소개한다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2609-2611
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• 2003

In this study, we explain the process and the technique required for implementing web-based remote control system based on embedded processor, SAl110, and embedded Linux. At first. cross-compile environment for target system should be constructed on host computer, and bootloader in charge of Linux booting may be loaded on the target system. Then, kernel image is compiled and loaded on the target system. Embedded Linux porting process is completed when ram disk image is generated. Finally, we load wed-server and device driver on the ram disk and make web-page for remote control using CGI. Through the above process, we implement web-based remote control system and present the result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.901-906
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• 2006

In this paper, we describe the implementation of the digital photo frame system that displays the images coming through the memory card of a digital camera. Each image can be recorded with voice in this system, and a function of the mp3 player is implemented as well. We use Intel PXA255 to control the system and modify the bootloader and linux kernel. Also we adapt device driver for this system. For the realization of image display, voice recording and mp3 playing in the basis of the linux system, we program some of the Microwindows system configuration files and program applications here. This study will be a good example to access the development of the digital photo frame based on the linux system using less-power and high performed embedded processor.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.6
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• pp.359-368
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• 2017

As the BadUSB is a vulnerability, in which a hacker tampers the firmware area of a USB flash drive. When the BadUSB device is plugged into the USB port of a host system, a malicious code acts automatically. The host system misunderstands the act of the malicious behavior as an normal behaviour for booting the USB device, so it is hard to detect the malicious code. Also, an antivirus software can't detect the tampered firmware because it inspects not the firmware area but the storage area. Because a lot of computer peripherals (such as USB flash drive, keyboard) are connected to host system with the USB protocols, the vulnerability has a negative ripple effect. However, the countermeasure against the vulnerability is not known now. In this paper, we analyze the tampered area of the firmware when a normal USB device is changed to the BadUSB device and propose the countermeasure to verify the integrity of the area when the USB boots. The proposed method consists of two procedures. The first procedure is to verify the integrity of the area which should be fixed even if the firmware is updated. The verification method use hashes, and the target area includes descriptors. The second procedure is to verify the integrity of the changeable area when the firmware is updated. The verification method use code signing, and the target area includes the function area of the firmware. We also propose the update protocol for the proposed structure and verify it to be true through simulation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.123-132
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• 2014

In this paper, we study the verification techniques for OS integrity that can be more fatal than applications in case of security issues. The dissemination of smartphones is rapidly progressing and there are many similarities of smartphones and PCs in terms of security risks. Recently, in mobile network environment, there is a trend of increasing damages and now, there are active researches on a system that can comprehensively respond to this. As a way to prevent these risks, integrity checking method on operation system is being researched. As most integrity checking algorithms are classified by verification from the levels before booting the OS and at the time of passing on the control to the OS, in which, there are minor differences in the definitions of integrity checking or its methods. In this paper, we suggests the integrity verification technique of OS using a boot loader and a physically independent storing device in the mobile device.