Re: Ada OS based on Minix3

[anon@anon.org (anon)]

There are a number of Ada OSs like that are Posix based: 
(All based on GNAT Ada)
	"Lovelace" by xavier grave (active project)
	MaRTE project (still activity)
	RTEMS project

For a kernel completely written in Ada may be an idea, but in today's world 
it might be hard to do.  A lot of kernel authors use GNAT, but GNAT was not 
designed to create stand-alone bootable code. And with GCC not fully 
supporting 16-bit code generation, GNAT can not fully generate a Legacy 
bootable code. But there may be hope, do to newer motherboards using newer 
BIOS based on INTEL EFI specs, like the AMIBIOS with Aptio EFI Firmware.  
These new BIOSs asap switch the processing mode to Protected-Mode then 
boot the OS as an 32 or 64 bit protected-mode application. Plus, 
protected-mode hardware device drivers can be loaded in a Flash device 
driver BIOS area. 

For older motherboard, one might try CoreBoot aka LinuxBIOS. But for now 
most people just use the GRUB boot loader which is written in C and that 
kind of defect the concept of 100% Ada OS. So, it might be take some time 
to see a true 100% kernel.

Note: ASUS, INTEL and others are schedule to use the new AMI Protected-Mode 
BIOS in the second/third quarters of 2008. Which means that someone should 
be able to write a multi-functional boot loader completely in Ada and then
the kernel in 100% Ada code for some.  But changing out all of the Legacy 
based BIOS or upgrade motherboards will still take a long time.

Now, I have written a couple of Ada (MBR) (Intel based) boot loaders using 
GNAT using gcc 3.2 that can boot an Ada kernel from either a floppy or 
bootable CD. It can be done using GNAT 2007 but the process is more involved.

Also at the movement I prefer nonposix design. Plus there is some talk that
the EFI Firmware spec may replace some of the POSIX spec. Plus, to me why, 
reinvent the wheel aka another Posix OS. Those who start to write an Ada OS 
kernel should prove that Ada is better by showing there is a better interface 
than just another Posix.  Maybe calling it Aside (Ada Operating System 
Interface) which could include a posix addon module.  This posix module 
could be use as a less secure interfere to existing non Ada software. But 
for the true ability of the Ada OS then an application would be needed to 
be written in Ada using Aosix.

And as for "c2ada" there is a couple of projects that do work, but they are at 
the movement limited to either Ada 83 or Ada 95 specs.  But with the Posix 
add on module to an Ada OS that would allow C code to be use, once the 
kernel and base apps are written in Ada.

As for using Minix 3 as a base for the an Ada OS.  If you borrow a routine or 
two that's OK, but to base a complete design on anyone else's work is just a 
type of plagiarism, that I am not into.  And you only prove that the original 
author could of used Ada, but not that Ada is better for writing an OS. Or that 
an Ada OS can stand on it on merits. The best why is to create a totally new 
design that take the best concepts from a majority of OS and try to limit the 
worst concepts that those OS have.


In <ed7d1ea9-bf0b-4e4a-b317-b57102853d65@p35g2000prm.googlegroups.com>, "Cedric.Lannock" <Cedric.Lannock@gmx.net> writes:
>Hi all,
>
>I came across Ada at the beginning of the year and read quite a few
>books about Ada. A few month later I joined a Linux workgroup within a
>local computer association. This way I learned about Ada and had a
>look into Tanenbaum's book on operating systems (http://www.amazon.com/
>Operating-Systems-Implementation-Prentice-Software/dp/0131429388/
>ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1226066518&sr=8-1) and Minix 3
>(http://www.minix3.org/).
>
>I thought about an operating system written fully in Ada. When surfing
>the net I came across the various discussions about that subject.
>
>What taking the Minix 3 system as basis for porting it to Ada? The
>Minix 3 is a modern micro kernel os and has about 4.000 Lines of code.
>It is full Posix compatible. Some guys have added real time
>functionality to it (see ACM.org for further reading). Thus it would a
>good place to start. As it has to few lines of code it should be
>possible to build a kernel in overseeable time.
>
>Another thought to get this project taking some speed would be not to
>rewrite all the available C code but to develop a translator c2ada. It
>would us getting startet and the resulting code could be enhanced and
>improved.
>
>Do you think this would make this project doable?
>
>Regards
>
>Cedric Lannock