Kontron NetBootLoader - Manual (Page 18)

ID 1022-8317, Rev. 2.0
NBL Operation NetBootLoader
Page 10
In the event a bootable FAT partition is not found or if a “net.cfg” file is not found or its execution
does not result in an image being loaded and started or the boot process being aborted, the
NetBootLoader executes the following command sequence: “dhcp; tftp; run”. If this command
sequence is not successfully executed, the boot process is aborted and a command interpreter
is made available for operator inputs.
2.6.3.3 Dual Core Operation (SMP/ASMP)
The NetBootLoader also supports the booting of modules with dual cores (for example, the
AM4100 and AM4101). Modules with dual cores can be operated using only one core, using
both cores with the same operating system (SMP), or using both cores with different operating
systems (ASMP).
Single core usage is principally the same as with modules with only one core. Dual core oper-
ation is a function of the application whereby two possible modes of operation are available:
symmetric multiprocessing (SMP) and asymmetric multiprocessing (ASMP).
In the case of SMP operation, the NetBootLoader itself runs using core 0, loads and starts the
operating system for core 0. Once the operating system is started, the OS starts the operation
of the second core (core 1).
For ASMP operation, the NetBootLoader itself runs using core 0, loads and starts different op-
erating systems for core 0 and core 1.
Essentially the standard boot process for both SMP and ASMP is the same with the exception
that when using ASMP mode, the NOR Flash image sequence is not supported. In this case,
the RUN command must explicitly specify the NOR Flash image to be used.
The alternate boot process is different for ASMP. In this case, only the “net.cfg” configuration
file is executed. If this does not result in images being loaded and started the boot process is
aborted and a command interpreter is made available.
2.7 Command Specifics
The following sections present either command specific or more detailed information on com-
mands as well as operational aspects of the NetBootLoader with regards to particular com-
mands.
2.7.1 ASSIGN
The use of this command requires a CPU module with two cores configured for asymmetric
multiprocessing (ASMP) operation. It permits the assignment of devices to one or the other of
the cores whereby a device may only be assigned to one core at a time.
A CPU module with two cores configured for symmetric multiprocessing (SMP) operation has
automatically all available devices assigned to core 0.
2.7.2 BL
When specified, this command stores a bootline in RAM for use of an image in the data buffer
at the time the image is started with the RUN command.
When ASMP operation is selected, this command is core sensitive, meaning that it can specify
the bootline to be used with the image for either core0 or core1 depending on the core selected
by the last issue of SETCORE. A bootline for each core may be specified.