Re: Boot.ini question

"Rod Speed" <rod_speed@xxxxxxxxx> wrote in message news:43ea3d52$0$3689$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Antoine Leca <root@xxxxxxxxxxxxxxxxx> wrote
Rod Speed wrote
Antoine Leca <root@xxxxxxxxxxxxxxxxx> wrote
Rod Speed wrote
Antoine Leca <root@xxxxxxxxxxxxxxxxx> wrote
Gerhard Fiedler wrote

ntldr may be able to load Windows
from drives the BIOS can't boot from

What you seem to miss is that Tim's
BIOS does not have such a concept.

[SNIP]

Problably yes. Like the most part of this thread...

[SNIP]

You are saying the same as I said: most of this thread
(not just the post quoted above) is irrelevant to the...
the whole point of this thread is what the rdisk() param means,

[SNIP]

Sure, one of my BIOS, and an awful large number of
other BIOSes out there as well, do have such drives;
yet, there are other BIOSes which allow to boot
easily from any drive recognized by the BIOS (BAID),

Not when its a logical drive in an extended dos partition.

Now *I* ask what is the relevance of this remark
with the whole point of the rdisk() parameter.

The whole point of the boot.ini was to allow
booting of what the bios could not boot.

Admitting.

That is STILL true of a logical drive in an extended dos partition,

What is true?

That few if any current bios can boot a
logical drive in an extended dos partition.

None can. The boot interrupt is Int19 and it is clearly defined.


If you want to do that, you need to use ntldr or another
loader to do that because the bios cannot do that.

Exactly, so no to "few if any".

To allow this to happen the functionality has to be incorporated
in the MBR bootcode and possibly the rest of track 0.


A boot loader allows to sever the link between the
booting (active) partition and the kernel location. Great.

[SNIP]

almost no current bios allows those to be booted by the bios.

Because that is not a BIOS' job,

Why not when the bios can boot any physical drive it can see.

Through Int19, that's why not. You have been told several times now.
It involves a change to *not* boot through Int19.


rather the one for the code inside the boot records
(MBR and the one for the active partition);

Thats just the way ntldr does it.

Yes.
NTLDR is absolutely nowhere without the bootcode in the MBR and
partition bootrecord.

It doesnt have to be done that way.
[SNIP]

There is no technical reason why the bios could not allow the user
to specify a logical drive in an extended dos partition to boot from,

it just isnt what is possible with most if any bios.

Because the BIOS is OS (and filesystem) independent.
The MBR bootcode and partition boot code are responsible for any
other/extra functionality.


if there is code at the beginning of the extended partition(s)
to load the logical one, and if there is the correct code in
the boot record of your logical drive, you'll succeed.

I perfectly know IBM/Microsoft's Fdisk does not store such code.

[SNIP]

I'm not aware of any that allows that.

Almost any BIOS is able to do it.

With the help of revised MBR bootcode.


Not boot a logical drive within an extended dos
partition without the use of a loader like ntldr.

Only because the functionality in NTLDR is far
to big to be crammed in the MBR and track0.


That is one of the reasons for the ntldr system.

Exactly.


For what it is worth, I think it is possible to succesfully
boot Ntldr in a logical partition, using bootstrap code
in EPBR and changing the HiddenSectors parameters.

I wasnt talking about that, I was talking
about where the OS comes from, not ntldr.

Then please reformulate, I did not catch your point at all.

That few if any bios can boot a logical drive that is in an
extended dos partition without ntldr or something similar
being used. That was one of the whole points of ntldr,
to allow that to be done, boot of a logical drive in an
extended dos partition, because the bios cant do that.

Nonsense. You don't need NTLDR for that at all.
Booting a nonprimary partition is dead easy.
Booting it on a different physical drive involves a bit more
but may still be done without the help of a program.
But since you need NTLDR anyway to get Windows in the air
there is no reason to do it differently from what it is now.


The very purpose of Ntldr+Boot.ini, like any
boot loader, is to enhance flexibility, yes.

And to allow booting that the bios cannot do, like
booting an install of the NT/2K/XP family from a
logical drive within an extended dos partition.

And booting several OS installed in the same
partition, perhaps of different vintage (something
that was really horrible back in OS/2 time).

[SNIP]

as I am saying since the first post after Tim's...

As I also said a number of times in this thread.

Yes :-). This thread is full of repetitions and not very useful
comments. I do not believe you and I are likely to learn anything.

[SNIP]
I wonder if anyone is going to learn anything at this point, in fact.

[SNIP]

If there aint even a hard drive boot order list, the rdisk()
param cant possibly be the ordinal in the hard drive
boot order list because there isnt one in some bios.

Was my point in the first place :-).
[SNIP]
One is that the ARC path rdisk(N) mechanism was designed around
1990 to make a gateway between the RISC world (where NT originally
was born) and the Intel/IBM/Compaq "i386" architecture; that's long
before BBS. I very much doubt if MS had the choice, they will still
use it in 2006 (NT on MIPS anyone?) As such, it is much of a
legacy of the history, like for example the Int13 interface itself.

Thats just plain wrong with the most basic functionality of boot.ini,

???
Read http://support.microsoft.com/kb/102873
(knowing that NT was born on MIPS)
[SNIP]
and you'll see that Boot.ini is a "solution" to supplement
the lack of a firmware way to record strings in a PC.
[SNIP]
to provide a way to specify where the various OSs etc are on the
hard drives. That has to do be done somehow with any boot manager.

It could have been done using the disk(N) parameter instead,
like with SCSI, and it would have worked equally well.

[SNIP]

The fact there are two indices is a given input, not a decision of the team.
[SNIP]
Using ARC paths including for i386 also was.
[SNIP]
N could also have been defined clearly as the BIOS drive number,
[SNIP]
also (signature() translates to scsi(128), for instance, although it came later).

[SNIP]

It surely is convenient to be able to boot from another
disk, but the main beef for the ARC path and boot.ini
is really with partition(N) and \WINNT, not rdisk(N).

[SNIP]

<snip>
Nothing grey about the MS statement that the rdisk()
param is the ordinal of the drive on the controller.

I did not find a clear statement from them that the
rdisk() parameter is the BIOS drive number - 80h.


Because it isnt.

Bullshit.
That is how MS stupidly implemented it, contrary to
what the documentation implies.
.

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