Authors data. If the target is a local resource,

Authors
have developed the RTOS as an extension to TOPPERS/ATK1, an OSEK-compliant
operating system developed by TOPPERS. In this regard they used the evaluation
board called M3A-HS50G50, on which SH7205 dual-core processor installed and which
were consist on-chip different memories. These memories can be accessed by both
CPUs. They used the semaphore registers of SH7205 to implement inter-core
locking. SH7205 has two CAN controllers which were related with each CPU core
one by one. So each CPU core engaged a CAN controller and directly become able
to send messages. Authors have implemented the resource management subsystem of
the RTOS and the processing flow of local, inter-core and inter-node resource
management. When an application task on a CPU core issues a system call for
resource management, the RTOS identifies the target resource by referring to
the extended configuration data. If the target is a local resource, the RTOS
executes the original resource management of TOPPERS/ATK1 and if the target is
an inter-core resource, the RTOS executes the inter-core resource management
module. Similarly, if the target is an inter-node resource, the RTOS executes
the inter-node resource management module. The inter-node resource management
module calls the CAN driver to send or receive request or release messages. The
data field of the release message is used to send the value of the inter-node
share variable. The size of the data field depends on the data size of the
shared variable. If the data size is greater than 8bytes, the data is divided
and transferred by separated messages (extended frame forat and standard frame
format).

Experimental Evaluation:

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They
have evaluated the system by measuring the CPU execution time and response time
of system calls, GetResource() and
ReleaseResource(), for an inter-node
resource except for the CAN communication time because the CAN communication
time changes depending on the state of the CAN bus.  Authors have separately measured the CPU
execution time of Request Transmission,
Lock and GetResource Local Processing of GetResource() and Release Transmission, Unlock and Release Resource Local Processing
of ReleaseResource(). They
have also measured the CPU execution time of system calls for an inter-core resource
and for a local resource. In these cases, the response time is the same as the
CPU execution time. We have also measured the original system calls of
TOPPERS/ATK1 for comparison. The execution time of the system calls has been separately
shown in the case that the priority level.