The Porting And Application Of ECos On Multimedia Mobile Phone Jasper

With the popularity of mobile phones and now consumers pay more and more attention to the multimedia capabilities for mobile phones. Multimedia mobile phone market demand is also growing. This paper used Coolsand existing GSM solution Jade and its own multimedia chip Lily, designed a new multimedia mobile phone solution--Jasper to rapid develop multimedia to occupy the market. This solution separated the basic voice and multimedia features. Jade responsible for GSM/GPRS services, including basic voice services, SMS, and so on. Lily responsible for multimedia application which supports MP3/WMA/AMR/JPEG/ MP4 codec, and the OS is embedded Configurable operating system (eCos). Jasper used the existing solutions and chips, reduced the development costs and technical risk. At the same time greatly reduced the development cycle, which is important for winning market.Around porting eCos onto new platform Lily, this paper analyzed the eCos system architecture firstly, and then discussed the core of eCos scheduling mechanism, exception and interruption, synchronization mechanisms, memory managent and etc. At the same time, this paper compared eCos with other opensource RTOS such as RTLinx,μC/OS-Ⅱ, and RTEMS. Each of RTOS task scheduling, synchronization and communication mechanisms, real-time performance are analyzed and compared. Then we focused on the design of eCos HAL layer, including architecture HAL, variant HAL and platform HAL. and then discussed the porting of HAL layer onto Lily in detail, including init SDRAM, the hardware process of exception and interruption, the control of UART and Timer, etc. Porting eCos HAL layer not only change the sources, but also change the CDL files and Id scripts, which also are discussed in this paper. Finally, this paper discussed how to set up the development environment of Jasper and configure eCos system.After completion of the porting and cusstomization of eCos, Jasper system was tested and the results show that the real-time and stability of system are meet the requirements, and can serivse the upper application well, which achieve the desired objectives.