Chaedeok Lim

ES-debugger : the flexible embedded system debugger based on JTAG technology

In the past the Embedded Software was used for controlling industrial apparatus but now is used in control systems for military, home appliances and automatic sensor systems and so on at present. Embedded systems are different from conventional computer system and this distinction makes it much difficult to debug as well as develop the embedded systems because of the lack of resources and sensitiveness in target system such as memory, power, timing constraint, etc. Especially huge integrated system like SoC (System-on-a-Chip)-that has memory, I/O port, etc.-has no space to locate debugging gadget so that the debugging of the embedded system is more difficult. To solve above problem, Boundary scan testing (also named JTAG) is appeared and we proposed the embedded system debugger based on JTAG technology in this paper

A development of remote tracepoint debugger for run-time monitoring and debugging of timing constraints on Qplus-P RTOS

In this paper, we present a new tracepoint debugging tool for microcomputer embedded systems, e.g., information appliances, which facilitates the instrumentation of the Qplus-P RTOS applications with timing constraints. Compared with traditional breakpoint debugger, our tracepoint debugger provides the ability to dynamically collect and record application data for online examination and for further off-line analysis. And, each tracepoint can provide the means for assigning new values to the running applications variables, without either halting its execution or interfering with its natural execution flow. In particular, our tracepoint debugger is different from previous ones in that we can specify and detect the timing violations using RTL (Real-Time Logic) trace experiments. Using our tracepoint debugger, the user is able to place the RTL tracepoints in his program. For each tracepoint, the user can specify the data to be collected or monitored using C in-line statements as well as RTL-expressions.

Experimental analysis on time-triggered power consumption measurement with DVS-enabled multiple power domain platform

Recently, the battery and low-power H/W technologies for mobile and wearable computing devices have been advanced rapidly. But on the other hand the computation and communication demands of the embedded applications are increasing more rapidly. Therefore, the application developers are still required to develop their codes to utilize the available energy as efficient as possible. The provision of software power measurement with reasonable accuracy, consistency and low overhead is an indispensable factor for software power engineering. In this paper, we present a time-triggered mechanism for providing energy consumption profiles in the level of C functions. The similar mechanisms have already been introduced at the previous researches such as PowerScope and ePRO. Instead, we, in this paper, introduce our efforts to extend these researches to incorporate power domains and DVS (Dynamic Voltage Scaling), then interpret these mechanisms as the view of time-triggered approach for better understanding to the relationships among timer interrupt, context switching, DAQ triggering, multi-channel DAQ delay, and etc. From our experimental results, we could conclude that the timetriggered approach for the function level energy measurement properly worked with low overheads and produced consistent energy consumption profiles on the DVS-applied program codes running upon the platforms supporting multiple power domains.

A remote diagnostic tool for USB kernel resources in the embedded Linux systems

Writing device drivers is known as very difficult developing process. In particular, writing low-level code for accessing devices and manipulating their kernel resources is tedious and error-prone. But, ever since the first device drivers have been written, their development process has made little progress. In this paper, we present a remote diagnostic tool for USB device kernel resources. This tool provides a method that device driver developers access devices and manipulating their kernel resources directly without writing any code for kernel programming. The presented tool in this paper, therefore, reduces the burden in developing USB device drivers and improves their productivity

A Design and Implementation of a Remote Debugging Environment for Embedded Internet Software

It is necessary to use development tools in developing embedded real-time application software for Internet appliances. In this paper, we describe an integrated remote debugging environment for Q+(QPlus) real-time kernel which has been built for an embedded internet application. The remote development toolset called Q+Esto consists of several independent support tools: an interactive shell, a remote debugger, a resource monitor, a target manager and a debug agent. Using the remote debugger on the host, the developer can spawn and debug tasks on the target run-time system. It can also be attached to already-running tasks spawned from the application or from interactive shell. Applicatoin code can be viewed as C source, or as assembly-level code. It incorporates a variety of display windows for source, registers, local/global variables, stack frame, memory, event traces and so on. The target manager implements common functions that are shared by Esto tools, e.g., the host target communiction, object file loading, and management of target-resident host tools memory pool and of target system symbol-table, and so on. These functions are called OPEN C APIs and they greatly improve the extensibility of the Esto Toolset. Debug agent is a daemon task on real-time operating systems in the target system. It gets requests from the host tools including debugger, interprets the requests, executes them and sends the results to the host.

A Software-Based Monitoring Framework for Time-Space Partitioned Avionics Systems

Recently, avionics systems have evolved into a time and space partitioning (TSP)-based integrated modular avionics (IMA) structure for integration into a single system from a variety of existing independently configured federated systems. The TSP-based IMA architecture is suitable for solving size, weight, and power problems in avionics systems. Partitioning real-time operating systems (RTOSs) to support TSP-based IMA have been researched, and the international aviation industry has established the ARINC 653 standard for a partitioning RTOS. The ARINC 653 standard has defined the health monitoring (HM) function for debugging. However, the HM of the ARINC 653 standard does not support monitoring and debugging functions, such as snapshot, cycle, and, redundancy monitor, which makes the system development hard. To this end, the purpose of this paper is to introduce a monitoring framework that supports high reliability and stability for RTOS and application software based on TSP structure used in avionics systems. The proposed monitoring framework is designed for Qplus-AIR, an RTOS based on the TSP structure that conforms to the ARINC 653 for aircraft systems. It is also applicable to other RTOSs based on TSP structure that does not conform to ARINC 653. It supports monitoring functions, such as snapshot, trigger, and cycle as well as various debugging functions. It also supports debugging and monitoring operations under the redundancy of avionics systems, and minimizes the intrusive effect, which is a disadvantage of the software-based debugging approach. These functionalities enable avionics system developers to monitor and measure the performance of TSP structure-based RTOS and application software in flight control system for unmanned aerial vehicles. Our evaluation results show that the proposed monitoring framework is suitable for monitoring and debugging of RTOS and application software based on TSP structure.

Dual display of virtual machines for automotive infotainment systems

We introduce GPU sharing between virtual machines on an embedded hypervisor. To achieve GPU virtualization, we apply an API remoting method which requires low overhead to OpenGL ES. For multimedia application, we target in-vehicle infotainment system and configure two guest virtual machines. The digital cluster is implemented on a bare-metal virtual machine. Furthermore, for multimedia application, we implement a linux-compatible 3D navigation. The framework can display both guest virtual machines on a single display panel so that output could be allocated separately on the panel. With this work, we explored how to virtualize GPU on a hypervisor for automotive systems.

Remote graphical processing for dual display of RTOS and GPOS on an embedded hypervisor

In this paper, we introduce a remote graphics library framework based on inter-virtual-machines communication in an embedded hypervisor. With this framework, there are no causality conflicts when multiple guest operating systems share one GPU. We adopted API remoting for GPU virtualization because it has relatively small overhead when connected with OpenGL ES standard library on embedded hypervisors. Interferences from the hypervisor during synchronization between front-end and back-end can be reduced by inter-VM commutation. To make improvement on size, weight and power for embedded systems, we opted for displaying both guest operating systems on a single display panel. The presented framework is applied to a real-world embedded hypervisor used for safety-critical systems. Our implementation runs an automotive digital instrument cluster on a real-time guest operating system and an in-vehicle infotainment application on a general purpose guest operating system within the hypervisor. We found it feasible for an embedded hypervisor to provide GPU service to heterogeneous industrial guest operating systems on a single hardware platform.

Device Dedication in Virtualized Embedded Systems

In embedded systems, hypervisors allow a virtual machine to access directly native hardware devices without sharing with other virtual machines because of conflictions of sharing devices between the virtual machines. In this paper, we present the issue being occurred to dedicate peripheral devices and how to solve it. With the device dedication technique on an embedded hypervisor, we identify the development considerations based on our observation. For proof-of-concept of our solutions, the partial virtualization technique about the clock controller is implemented to a real embedded hypervisor for safety-critical systems.

Linux Based Real-Time Feature Supporting Method and Evaluation for Information Devices

Recently, demands of information devices are increasing as we can find so many information devices around us such as smartphone, mobile internet device (MID), tablet. These characteristics of information devices services should support soft real-time based time guaranteed multimedia services and control internet appliances. In this situation, soft real-time supported system should be developed to consider as a total aspect of hardware, kernel, middleware, application. But this paper will describe soft real-time supporting and evaluation methods for information device as an aspect of only kernel.