RAM 6.0 BUX II Series Guia do Utilizador descarregar pdf (Página 36)

VxWorks

BSP Developer’s Guide, 6.0

The routine romStart( ) is essentially a loader. It performs the necessary

decompression and relocation for the ROM images. First, it copies the text and data

segments from ROM to RAM. Then, it clears those parts of the main RAM not

otherwise used. Finally, romStart( ) decompresses the compressed portion of the

image. Different configuration options can modify how these operations are

performed.

usrConfig.c

The usrConfig.c file contains the usrInit( ) and usrRoot( ) routines. When

usrRoot( ) completes, the VxWorks boot is complete. Both usrInit( ) and usrRoot( )

are architecture-independent, and thus should not need to be changed.

During BSP development, the usrConfig.c file is usually copied into the BSP

directory and modified to allow the user to control what hardware is initialized

(this is achieved by removing portions of usrRoot( ) using #if FALSE/#endif

pairs). The temporary copy must be discarded when the BSP is complete.

Therefore, changes should be limited to debug code only.

2.3.2 Derived Files

The most obvious files derived from the BSP files are the VxWorks images. There

may be multiple copies of VxWorks images present in a BSP directory, each

representing a different build type. For example, it is possible for the BSP directory

to contain bootrom, bootrom_uncmp, vxWorks (and its vxWorks.sym file),

vxWorks.st, and vxWorks.res_rom as well as several other images all at the same

time.

In addition, building the source files in the BSP directory generates object files.

There is not a one-to-one correspondence between source files and object files. As

mentioned in sysLib.c, p.25, the sysLib.c file uses the #include compiler

preprocessor directive to include other source files, especially the sysDev.c files.

For example, in the wrSbc8260 BSP, there is a file called sysIOPort.c that contains

interface code for the PowerPC 8260 I/O port drivers. The #include is as follows:

NOTE: The bootInit.c file is shared by all BSPs. Because of this, you must ensure

that changes made to bootInit.c do not impact the functionality of other BSPs.

NOTE: The usrConfig.c file is shared by all BSPs. Because of this, you must ensure

that changes made to usrConfig.c do not impact the functionality of other BSPs.

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RAM 6.0 BUX II Series Guia do Utilizador Página 36