The TOPPERS/JSP kernel is a real-time kernel that is in conformity
specification. It is also the first development result by the
TOPPERS Project. JSP is an acronym for Just Standard Profile, and as
the name shows, is implemented in accordance with the µITRON4.0
specification standard profile regulation. The latest JSP release can
be downloaded from here.
Main features are as follows:
Easy to read and reconstructible source code
Keeping in mind that utilization would be for research and
development, emphasis was put on easy to read and reconstructible
source codes. The algorithm, although easy to read, is not
inefficient. For example, by using heap structure to manage time
events, a complex but efficient algorithms are employed.
Porting to other targets is easy to do
C language is used for most parts of the kernel. Clear separation of
target independent parts and target dependent parts are made,
therefore making porting to other target processors and systems is
made easy. There have been reports where, if the target processor
architecture is familiar, that porting was accomplished in three days.
High efficiency performance and low RAM usage
For a kernel where most parts are written in C, high efficiency
performance and low RAM usage is realized.
Simulation environment on Linux and Windows
Simulation environments for JSP kernel to run on Linux and Windows are
available. These simulation environments switch multiple tasks within
one process in Linux/Windows. It is the best suited for proto-type
development of embedded systems, logic level verifications, and
real-time learning experiences.
It is possible to construct systems solely using free software
GCC and GNU develop environment are standard software develop
environments. Therefore the user can acquire not only the kernel
itself, but also the develop environment free and develop a system.
As a JSP kernel simulation environment, a Linux based environment and
a Windows based are available. These simulation environments are
activated within a process of Linux/Windows by switching multiple
tasks, and can be used as a thread library as well.
Also in the below processor, by applying program(s) provided by GNU
and develop tool environment provided by manufacturers embedded
microcomputer actions can be simulated on personal computers and can
activate JSP kernel without having assessment boards ready. For
simulation tool information, see the document attached to the JSP
kernel release package.
GNU develop environment such as GCC is appointed as TOPPERS/JSP kernel’
s standard software develop environment. GCC extension functions, such
as inline function and inline assembler function, are utilized in some
parts. However, for target processors not supported by the GNU develop
environment, other type of compiler is utilized. For example, Visual
C++ is used for Windows simulation environment.
Patch for GCC
A patch is necessary when using C++ binding with JSP kernel 1.4., the following patch is used for avoiding impediment which occurs during the make process of GCC3.2.3 on Cygwin.
For details, see the document included in the JSP kernel kit or
replies of the users mailing list.
GNU develop environment
Within the GNU develop environment BINUTILS, GCC_CORE and GDB is
specifically needed. If a standard library is necessary for the
application program, NEWLIB can be employed. Cygwin is needed if the
develop environment is constructed on Windows. Source codes can be
downloaded from the following links:
When performing a remote debugging utilizing GDB (GNU debugger) by
connecting the host machine and target system using a serial
interface, a program called a stub is needed on the target system.
The following are stub source programs which have been reconstructed
so is can be used with the TOPPERS/JSP kernel.
Simple monitor for H8 is distributed below. The H8 flash ROM by
Renesas Technology Corp. has limited rewrite capacity. Therefore,
writing the debug module to the flash ROM and debugging is not an
ideal method. The H8 simple monitor is a program which loads the debug
module to RAM for execution.
Write the H8 simple monitor to the flash ROM and load the debug module
to the RAM of the H8 or a RAM setup externally for debugging. By this,
the problem of limited times of rewriting to the flash ROM can be
The below is a summary of the H8 simple monitor.
The target system is AKI-H8/3048F, 3052F, 3068F and 3069F by Akizuki
Denshi Tsusho Co.
The monitor is designed to conform with the TOPPERS/JSP kernel for H8,
and it is possible to load a debug module embedded with the
TOPPERS/JSP kernel for H8 to RAM and execute.
A virtual interrupt vector can be set in the internal RAM of the
H8. The H8/3048F is compatible with the monitor debugger by Akizuki
Denshi Tsusho Co.
There is a function to display/change the memory contents.