More and more embedded systems choose ARM-based micro-controllers as CPU. If no embedded OS built with the system, the application scope will be restricted. Therefore, the need of embedded OS is vital. There are many embedded OS¡¦s in the market, but the embedded Linux has many advantages and is widely accepted. Commercial embedded Linux takes less refund than other embedded OS¡¦s. The kernel and most applications are distributed in GPL open source copyright, and is highly portable to many machine platforms. Presently, the hardware key-technology is highly skilled. The margin of 3C industrial has gone down rapidly. Therefore, people focus on adapting integrated technology to practicality and innovation to make cost down. Developers choose appropriate ARM micro-controllers according to demanding functionality of their products. The microcontroller is not necessary running with Linux distribution. Two approaches can be used to resolve the embedded OS issue. The first approach is porting Linux to the platform without any refund. The second approach is to pay for commercial Linux. Embedded system peripheral devices aim at powerful functionalities and economy. For instance, UART interface is cheap and low data transfer rate. The target board communicates with host via RS-232. RS-232 acts as serial console to play dumb terminal under Linux. Industrial applications often make use of RS-xxx for UART physical transmission layer. For instance, RS-485 applies modbus protocol to build cheap monitor systems. Network transmission is a necessary function, and it generally achieves high data transfer rate application through Ethernet. The UNIX-like network socket has served network application very well. Embedded systems are usually diskless systems. In order to keep permanent data, using flash memory as block disk system is a widely adapted strategy and which operates flash memory through MTD subsystems¡][28]¡^. An MTD subsystem contains two different modules, ¡§user¡¨and ¡§driver¡¨. In the driver module, CFI¡][40]¡^ is applied to probe flash chip, partition it and provide operating function. Flash translation layer and file-system are applied in the user module. MTD BLOCK is used to emulate the flash partitions as block devices which are then mounted into Linux virtual file system¡]VFS¡^with JFFS2 type, designed according to the feature of flash devices. In this thesis, we will describe in detail the procedure of porting Linux to ARM micro-controllers. The motivation of the work is introduced in chapter 1. In chapter 2, we introduce development tools and the main flow of the porting procedure. In chapter 3, we describe the LH79525 platform and the main perepherals on the target board, then introduce the ARM programmer model. In chapter 4, we examine the required knowledge and the important issues for porting ARM Linux. In chapter 5, we describe the details of porting Linux to run with Sharp LH79525, including modifying the key source codes and adjusting kernel configuration for embedding the UART, ethernet MAC, and MTD subsystem. In chapter 6, we do step-by-step validation and apply an integrated application with the LF-314CP temperature controller¡][46]¡^ by law-chain technology for the LH79525 target board running with the ported ARM Linux. In chapter 7, we present some issues for future work and improvement, then make a conclusion for the thesis.

Today, many small aerodromes have a hard time surviving economically, and amongst the largest cost is air traffic control. Airlines are cutting costs where they can, and many times this affects the aerodromes as well, e.g. when airlines decide to park remotely instead of at the gate. The project called Remotely Operated Towers, initiated by SESAR and run by Saab and LFV, is aiming to address this problem. The project revolves around remotely providing ATS to aerodromes where it is deemed suitable. A big challenge in this project is how to assign aerodromes to remote tower modules in the remote control centre. There are many ways to do this, but there is only a few ways to do it to achieve the least amount of modules. This thesis aims to find an optimal solution to the challenge mentioned above. The thesis resulted in a model where the user can provide the input of choice, i.e. aerodromes with associated ATS operating hours and movements, for a specific period – and receive the assignment schedule for the modules, saying exactly which aerodrome are to be controlled by which module at what time.

New PCI-e flash cards and SSDs supporting over 100,000 IOPs are now available, with several usecases in the design of a high performance storage system. By using an array of flash chips, arranged in multiple banks, large capacities are achieved. Such multi-banked architecture allow parallel read, write and erase operations. In a raw PCI-e flash card, such parallelism is directly available to the software layer. In addition, the devices have restrictions such as, pages within a block can only be written sequentially. The devices also have larger minimum write sizes (>4KB). Current flash translation layers (FTLs) in Linux are not well suited for such devices due to the high device speeds, architectural restrictions as well as other factors such as high lock contention. We present a FTL for Linux that takes into account the hardware restrictions, that also exploits the parallelism to achieve high speeds. We also consider leveraging the parallelism for garbage collection by scheduling the garbage collection activities on idle banks. We propose and evaluate an adaptive method to vary the amount of garbage collection according to the current I/O load on the device. For large scale distributed storage systems, flash memories are an excellent choice because flash memories consume less power, take lesser floor space for a target throughput and provide faster access to data. In a traditional distributed filesystem, even distribution is required to ensure load-balancing, balanced space utilisation and failure tolerance. In the presence of flash memories, in addition, we should also ensure that the numbers of writes to these different flash storage nodes are evenly distributed, to ensure even wear of flash storage nodes, so that unpredictable failures of storage nodes are avoided. This requires that we distribute updates and do garbage collection, across the flash storage nodes. We have motivated the distributed wearlevelling problem considering the replica placement algorithm for HDFS. Viewing the wearlevelling across flash storage nodes as a distributed co-ordination problem, we present an alternate design, to reduce the message communication cost across participating nodes. We demonstrate the effectiveness of our design through simulation.