"cquirke (MVP Windows shell/user)" wrote:
Hey thanks!
Too many people nowadays use "boot" to mean "load".
Or "download" to mean "install" ... said:
If you can remember when a "boot instruction" was a single
machine instruction set on physical switches by hand and
a "boot loader" was contained on a single punched card,
you automatically know the difference.
I can't - I was in a different faculty in those days, so while my
engineering flatmates were going "ERROR EABT heh heh" to each other, I
was headscratching though orgasmic chemistry.
But what would you call ntldr? It's not in the C:\WINDOWS
folder and thus not part of the OS
Oh, it's part of the OS, alright. The OS starts in the first sector
of the active primary partition - that's where the system hands off to
the OS's pre-filesystem code. NTLDR is to NT what IO.SYS is to DOS
and Win9x; it's the first code file to be loaded for the OS.
What makes it a bit confusing is that one can dip into NT this way,
and then immediately jump out again to load a different OS instead -
either DOS mode, a Win9x, or Recovery Console. Those OSs are loaded
in the same way; NTLDR loads a partition boot sector code image as if
that had been in effect as the partition code, and jumps into that.
But by your definition, it's not part of the "boot" process.
Is it right to call it just a "loader"?
No, it's part of NT (NT, Win2000, XP). It's just that the OS you
start loading isn't always the OS you finish loading ;-)
It's like when you F8 you way into Win9x's boot menu, and load DOS
mode (Command Prompt Only) or even MSDOS (Previous Version of MSDOS)
instead of Win95/98. The IO.SYS that starts the boot process for
these OSs is common to both DOS mode and Win9x, but can change gears
and load an older MSDOS instead. Mind you, if you do that in
Win95SR2, you'll struggle to get back!
In the interests of accuracy, I have to mention that Recovery Console
isn't an OS, in that it cannot host programs other than itself. It
feels a bit like the MS-DOS 4.00 incarnation of DOS Shell; one hopes
it is the precursor of better things to come in future OS versions.
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Gone to bloggery:
http://cquirke.blogspot.com