BSP Developer's Guide

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BSP Organization
further board initialization that could not be completed in sysHwInit( ); for
example, an intConnect( ) of additional devices may be done in sysHwInit2( ).
The 60 Hz system clock is set up by calling sysClkRateSet( ) and sysClkEnable( ).
VxWorks can be booted without the system clock running. However, network
drivers, when they attach, usually execute a taskDelay( ) to allow hardware reset
to complete. If the system clock is not running, the delay does not expire, causing
the system to hang.
The system clock can be dynamically changed from the shell or application
programs. However, facilities that take a “snapshot” of the clock rate (for example,
spyLib) can be broken by such an unexpected rate change.
If INCLUDE_IO_SYSTEM is defined in configAll.h, the VxWorks I/O system is
initialized by calling the routine iosInit( ). The arguments specify the maximum
number of drivers that can be subsequently installed, the maximum number of
files that can be open in the system simultaneously, and the desired name of the
“null” device that is included in the VxWorks I/O system. This null device is a
“bit-bucket” on output and always returns end-of-file for input.
The inclusion or exclusion of INCLUDE_IO_SYSTEM also affects whether the
console devices are created, and whether standard in, standard out, and standard
error are set; see the next two sections for more information.
If the driver for the on-board serial ports is included (INCLUDE_TTY_DEV), it is
installed in the I/O system by calling the driver’s initialization routine, typically
ttyDrv( ). The actual devices are then created and named by calling the driver’s
device-creation routine, typically ttyDevCreate( ). The arguments to this routine
include the device name, a serial I/O channel descriptor (from the BSP), and input
and output buffer sizes.
The macro NUM_TTY specifies the number of tty ports (default is 2);
CONSOLE_TTY specifies which port is the console (default is 0); and
CONSOLE_BAUD_RATE specifies the bps rate (default is 9600). These macros are
specified in configAll.h, but can be overridden in config.h for boards with a
nonstandard number of ports.
PCs can use an alternative console with keyboard input and VGA output; see your
PC workstation documentation for details.
The excInit( ) routine is called to initialize exception handling. Other facilities are
optionally initialized at this point, as specified by macros in configAll.h. (See also
VxWorks Programmer’s Guide: Configuration.)
If INCLUDE_WDB is defined, wdbConfig( ) in src/config/usrWdb.c is called. This
routine initializes the agent’s communication interface, then starts the agent. For
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