Seminar mc palm

PALM

1. PALM Operating System Amal Mohanan CV S7 IT-A 14150008

2. INTRODUCTION Palm OS (also known as Garnet OS) is mobile operatig sytem initially developed by Palm,Inc, for personal digital assistance in 1996. Palm OS is embeded OS designed for ese of use with touch screen . It is run on Arm architecture based processors. it is designed as 32 bit architecture.

3. An Overview of Palm OS Designed for special hardware small screen ( 160 x 160 ) less processing power than desktop PCs limited memory ( 512k ~ 8MB ) no disk drive or PCMCIA disk

4. The Appearance of a PalmPilot

5. System Architecture

6. Memory Orgnization Motorola 68328 uses 32-bit addresses External data bus is only 16 bits wide ROM - stores the main suite of applications ( the OS itself) RAM - stores additional and replacement applications & system extensions RAM - dynamic RAM & storage RAM

7. Dynamic RAM Served as temporary space for allocation Analogous to the RAM installed in a typical desktop system Is cleaned after reboot Implement a single heap that provides memory for dynamic allocations( TCP/IP, IrDA , …)

8. Storage RAM Holds nonvolatile user data ( appointments, to do lists, memos, address lists, … ) Is accessed via calling the database manager or the resource manager Analogous to the disk drive of a typical desktop system

9. The Data Manager The database is analogous to disk A database is a collection of records A record is mapped to a memory chunk A database accesses its records by storing their local ID’s An application requests a particular record in a database by index

10. The Resource Manager Resources : store the UI elements of an application, such as images, fonts, dialog layouts, … Resource manager : Data manager with the additional ability of tagging each chunk of data with a unique resource type and resource ID

11. Application Structure Single threaded Event-driven PilotMain () corresponds to main() in C PilotMain -- Response to launch codes An event loop in response of a normal launch

12. Developing Apps on Palm Various development tools: Code Warrior for Palm OS Palm SDK (header files, documents, examples) GCC POSE - An open source Palm emulator runs on Windows, Mac and UNIX

13. Conclusion The Palm OS provides a good platform for developing Palm apps The Palm OS provides various libraries for communicating with PC’s A good OS design is not necessarily having the most advanced feature, but having the best integration of the hardware

14. The End