RAM 6.0 BUX II Series Guía de usuario descargar pdf (Pagina 34)

VxWorks

Hardware Considerations Guide, 6.0

Recovering During Garbage Collection

After a fault, any garbage collection in process at the time of the failure must be

restarted. Garbage area is space that is occupied by sections that have been deleted

by the host. TrueFFS reclaims garbage space by first moving data from one transfer

unit to another, and then erasing the original unit.

If consistent flash failures prevent the necessary write operations to move data, or

if it is not possible to erase the old unit, the garbage collection operation fails. To

minimize a failure of the write part of the transfer, TrueFFS formats the flash

medium to contain more than one transfer unit. Thus, if the write to one transfer

unit fails, TrueFFS retries the write using a different transfer unit. If all transfer

units fail, the medium no longer accepts new data and becomes a read-only device.

This does not, however, have a direct effect on the user data, all of which is already

safely stored.

Recovering During Formatting

In some cases, sections of the flash medium are found to be unusable when flash is

first formatted. Typically, this occurs because those sections are not erasable. As

long as the number of bad units does not exceed the number of transfer units, the

medium is considered usable as a whole and can be formatted. The only noticeable

adverse effect is the reduced capacity of the formatted flash medium.

9. Virtual Memory Library

The vmBaseLib (the base virtual memory support library) and the vmLib (the

VxVMI option) have similar BSP requirements. Because vmBaseLib is bundled

with VxWorks, BSPs are written to include it by default. If the VxVMI option is

installed, the end user need only change

INCLUDE_MMU_BASIC to

INCLUDE_MMU_FULL in target/config/bspname/config.h to include the

unbundled library in future builds.

For more information, refer to the vmBaseLib and vmLib reference entries and

your VxWorks programmer’s guide.

NOTE: The optional VxVMI product is not available forVxWorks 6.x. For

information on optional products supported with your release, see your product

release notes.

1 2 ... 29 30 31 32 33 34 35 36

Sin comentarios

RAM 6.0 BUX II Series Guía de usuario Pagina 34