| RI is reference implementation released
from SUN Micro-system. Of course, it is most common reference
for all of us. But RI is not real business solution for
us. Because most of it does・t design for a real hardware
environment, it just designs for workable. It consumes
lots of resource to do graphic implementation and waste
so many memory footprints to do instance creation. RI
do been a reference model but it・s still important for
KVM porting.
The basic hardware requirements of KVM
are a small storage to store java runtime classes, small
memory heap for runtime requirement, a simple keypad
to produce a key inputting and a generic graphics system
to show GUI. Most of these assumptions are right but
not all of compact devices have a generic graphics system.
Some devices just provide a vide buffer for read and
write image data and don・t have a graphics system like
your PC. For these machines, you need implement a basic
primitive drawing and imaging functions. I suggest implementing
a small generic graphics system and replacing the graphic
code of RI. Of course, I will mention this issue at
next topic. The biggest challenge is that RI assumes
all of target device owning a whole standard C runtime
library. I must say this assumption is not right. Most
of devices don・t implement such a huge C library but
a compact version of CRT. Here is a list of porting
requirement.
- Memory Management
- Storage System (RMS)
- File System (For Classes Loading)
- Graphics System
- Input Device (Keypad or Touch pad)
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