Re: HAL (was AdaOS)

["Hans-Olof Danielsson" <Hans-Olof.Danielsson@swipnet.se>]

"Nick Roberts" <nickroberts@adaos.worldonline.co.uk> skriver:

> Your enlightenment is appreciated, but I'm sorry, I'm afraid it sounds a
bit
> like someone trying to sell me a pair of boots that will do all the
walking
> for me. ........

In her book "Inside Windows NT" Helen Custer describes *NT's pair of
boots*  %>) like this:

"Hadware abstraction layer (HAL). Places a layer of code between the NT
executive and the hardware platform on which Windows NT is running. It
hides hardware-dependent details such as I/O interfaces, interrupt
controllers
and communication mechanisms. Rather than access hardware directly, NT
executive components maintain maximum portability by calling the HAL
routines when they need plattform-dependent information.
.....
Platform-dependent code - that is, code that relies on a particular
manufacture's implementation of a MIPS R4000 computer, for example
- is located in the HAL and is proveded by individual computer manufaturers.
Device drivers contain device-specific code, of course, but they aviod
processor-dependent and platform-dependent code by calling NT kernel
routines and HAL routines."

One thing one can wonder over is how heavy NT's pair of boots are.

Hans-Olof Danielsson