VxWorks
Kernel Programmer's Guide, 6.9
xvi
Example of Installing a Driver ........................................................................ 315
12.14.2 Devices ................................................................................................................ 315
The Device List and Adding Devices ............................................................. 316
Example of Adding Devices ............................................................................ 316
Deleting Devices ................................................................................................ 317
12.14.3 File Descriptors .................................................................................................. 319
File Descriptor Table ......................................................................................... 320
Example of Opening a File ............................................................................... 320
Example of Reading Data from the File ......................................................... 322
Example of Closing a File ................................................................................. 323
Implementing select( ) ...................................................................................... 323
Cache Coherency ............................................................................................... 326
13 Local File Systems ..................................................................................... 331
13.1 Introduction ...................................................................................................................... 331
13.2 File System Monitor ...................................................................................................... 333
Device Insertion Events .................................................................................... 334
XBD Name Mapping Facility .......................................................................... 335
13.3 Virtual Root File System: VRFS ................................................................................... 335
13.4 Highly Reliable File System: HRFS ............................................................................ 337
13.4.1 Configuring VxWorks for HRFS ..................................................................... 337
13.4.2 Configuring HRFS ............................................................................................ 338
13.4.3 Creating an HRFS File System ....................................................................... 339
Overview of HRFS File System Creation ....................................................... 339
HRFS File System Creation Steps ................................................................... 339
13.4.4 HRFS, ATA, and RAM Disk Examples .......................................................... 340
13.4.5 Optimizing HRFS Performance ...................................................................... 345
13.4.6 Transactional Operations and Commit Policies ......................................... 345
Automatic Commit Policy ............................................................................... 345
High-Speed Commit Policy ............................................................................. 346
Mandatory Commits ......................................................................................... 346
Rollbacks ............................................................................................................. 346
Programmatically Initiating Commits ........................................................... 347
13.4.7 File Access Time Stamps .................................................................................. 347
13.4.8 Maximum Number of Files and Directories ................................................. 347
13.4.9 Working with Directories ................................................................................ 347
Creating Subdirectories .................................................................................... 348
Removing Subdirectories ................................................................................. 348
Reading Directory Entries ................................................................................ 348
13.4.10 Working with Files ............................................................................................ 348
File I/O Routines ............................................................................................... 348