minix
J.Ja...@sheffield-city-poly.ac.uk
arrive in the post to install linux, so while I was waiting I thought
I'd have a quick read of Tanenbaums book 'Operating Systems,
Design and Implementation.' (This contains the source code to
MINIX). Two things.
1. The source code for init and the shell are not included (in the
book). How different are the linux versions from the 'original' MINIX
versions?
2. On page 13, he says 'When UNIX was young (Version 6), the source
code was widely available, under AT&T license, and frequently
studied. John Lions, of the University of New South Wales in
Australia, even wrote a little booklet describing its operation, line
by line. This booklet was used (wuth the permission of AT&T) as a
text in many university operating system courses.'
Has anyone ever heard of this booklet before ?
Is this booklet still available ?
If so does anyone know where I can get a copy of it ?
JJ
:: Jon Jagger asj...@oak.scp.ac.uk
:: Sheffield City Polytechnic, Pond Sreet, SHEFFIELD S1 1WB
:: Tel 0742 533802/432889 (work/home) Fax 0743 533840
:: Newspaper ad: Men wanted for expanding contracting company!
Linus Benedict Torvalds
>Hello, Linux newbee JJ here. I'm still waiting for a hard disk to
>arrive in the post to install linux, so while I was waiting I thought
>I'd have a quick read of Tanenbaums book 'Operating Systems,
>Design and Implementation.' (This contains the source code to
>MINIX). Two things.
>
>1. The source code for init and the shell are not included (in the
>book). How different are the linux versions from the 'original' MINIX
>versions?
I get the feeling you think linux evolved from minix? This is not true:
linux was written under minix, and while linux superficially resembles
minix386, it's really not that close to minix in any way... The most
minix-like feature in linux is the filesystem: due to practical reasons
I wanted to have the same physical layout of the disk as in minix.
Reading Tanenbaum is good for a general idea of operating systems, but
it's generally not worth it to read the minix specific bits in order to
understand linux (reading the minix source code in order to understand
the genera idea might be worth it). While the filesystem has the same
physical layout, multithreading means locking etc needs to be done
totally differently etc. The kernel proper also uses totally different
design ideals, and the device drivers are also very different (ie they
use interrupts directly instead of waiting for hardware messages etc).
Lastly, minix and linux memory management is fundamentally different:
linux uses paging on a very low level for everything: minix uses a
heap-like memory management strategy, I think.
As to the shell under linux: there are several (although bash is the
only one I use), and the same shells are generally available for minix
as well (not standard PC-minix: it can't run tcsh/bash due to the 64kB
limit). The standard minix shell isn't available for linux (not that
big a loss: the minix shell doesn't do your mental sanity much good):
ash is probably the closest thing.
I don't know about /bin/init: I never looked at the sources under minix,
and I haven't exactly dissected it under linux either.
> [ Lions book ]
>Is this booklet still available ?
>If so does anyone know where I can get a copy of it ?
I doubt you'll find a copy of the Lions book: I think the only way to
get your hands on it would be to find somebody who did the course and
photocopy it off him. I don't think AT&T allows that kind of thing any
more, so it's probably illegal.
Linus
Drew Eckhardt
>arrive in the post to install linux, so while I was waiting I thought
>I'd have a quick read of Tanenbaums book 'Operating Systems,
>Design and Implementation.' (This contains the source code to
>MINIX). Two things.
>
>1. The source code for init and the shell are not included (in the
>book). How different are the linux versions from the 'original' MINIX
>versions?
You are confused : Linux has no code in common with Minix. As
an artifact of development, Linux uses the Minix filesystem
with symlinks added, but even that has no Minix code.
>2. On page 13, he says 'When UNIX was young (Version 6), the source
>code was widely available, under AT&T license, and frequently
>studied. John Lions, of the University of New South Wales in
>Australia, even wrote a little booklet describing its operation, line
>by line. This booklet was used (wuth the permission of AT&T) as a
>text in many university operating system courses.'
>
>Has anyone ever heard of this booklet before ?
Yes.
>Is this booklet still available ?
No.
>If so does anyone know where I can get a copy of it ?
There are photocopies of photocopies of photocopies circulating
around, you might be able to get these.
If you're interested in studying a "real" Unix source,
take a look at BSD Net-2 - it's still incomplete, but
much of it is there. An even better bet is that your
university may have a source license, and you may
be able to sign a source agreement and see the source.