Mitchell, Jerry talks in glowing terms about JAVAOS because WIND is
one of the companies that licensed it from SUN. It is confusing, in
that JAVAOS is only an OS under very specific circumstances where the
target application is PURE JAVA. JAVAOS, by itself, cannot support
any application written in any other programming language other than
JAVA. It is structured so that it can run by itself OR as an integral
part of another (RT)OS. It has no real-time capabilities of its own.
SUN cites a telephone handset as an example of an application where
an embedded RTOS would provide the foundation for JAVAOS. They talk
about a NC-type machine, designed specifically for that purpose, as
an example of a pure JAVAOS implementation. Remember, though, that
real-life NCs have to account for legacy applications, so a pure
JAVAOS wouldn't fill the bill. There would still be a requirement for
an underlying (RT)OS to host JAVAOS. It's really more pratical to
think of JAVAOS as a portable JAVA execution environment, at this
point.
In addition, all the network software and device drivers in JAVAOS
are written in JAVA, which makes it very portable, but inherently
slower than native implementations of these functions found in more
traditional (RT)OSs like VxWorks. Basically, on any given processor,
VxWorks will outperform JAVAOS when it comes to I/O, by a good margin.
Lastly, much like WinCE, JAVAOS simply doesn't have the hardware
support that VxWorks has. It is currently available for the Sun SPARC,
Intel-compatible x86, and StrongARM processors. It has very limited
interface/controller chip support and, as stated above, the
performance of these device drivers is not optimal. SUN, unlike MSFT,
realizes that it will get much better hardware coverage, much faster,
by allowing JAVAOS configurations that exploit existing, established
(RT)OSs. SUNs goal is to make JAVA as ubiquitous as possible, as fast
as possible, and they are more than happy to let WIND help them.
----------
The SUN server motherboard is not specifically for the NC, its a
UltraSPARC-based motherboard intended for general purpose server
applications, one of which would be serving NC clients. Any server
running HTTPD can act as a NC server, and perform other chores at
the same time, for that matter. The big news is that SUN, the last
remaining major computer manufacturer to shun the PCI bus, is showing
signs of caving in. This is good news for I2O, even though this
initial product does not have an i960RP on the motherboard. The fact
that the PCI bus is supported means that I2O-compliant peripheral
adapters can be installed. The only requirement is that the OS have
an OSM driver installed (software). Since SUNs Solaris OS also runs
on the PC platform, it will have to supply an I2O OSM driver at some
point, or risk not supporting the highest performance peripherals
available, which isn't likely. I2O is definitly not restricted to PCs
anymore!
Hope this helps!
-Dave Lehenky
P.S. Sorry for getting up on my soapbox this past week with regard
to MSFT/Bill Gates. I'll try to confine myself to technical
matters in the future. |
