easyBCD: give options for specifying drive paths

#1
easyBCD asks us to specify Drive path of varies O.S. that we have on current disk(s).

I find it confusing.

Whenever we boot from different o.s., window has some cryptic system of assigning drive letters to them, which is definitely not in the sequence of hard disks and also not in sequence of position of physical partition on the hdd.

Also, Windows always makes boot drive to become C,
and that changes the Drive name alphabet of all drives in all our disks.

so, when we are defining various drive paths for multiple boots, we don't remember and don't know what drive letter windows is going to assign to them.

of course, we have to assign the drive letter as it is in the current booted o.s. system.
But this also changes if we add a new hard disk or pen drive or any other device having a disk like functions.

And if we have to assign the current letters of drive paths, then the same will change, when we use Easy BCD in different o.s. to define boot menu options for that o.s.

I think some more help in assigning drive letters in boot menu would be helpful.

either it could even show the hard disks status as is shown in disk management screen, so that it is clear what is assigned to what.
or it could pick volume name of the said drive path and display as a read only remark, so that we could be sure that it has selected the correct drive.

or some other method that you feel would fulfill the requirement better.

Thanks.
--
Rawat
 

Terry60

Knows where his towel is.
Staff member
#2
Disk letters don't really exist.
They're just virtual labels given to partitions/devices by Windows when you boot it.
All early Windows assigned these virtual labels dynamically at boot time, in the order they were detected by plug and play code in the BIOS.
Current versions of Windows default to the same action if you do not take action to make permanent assignations yourself.
You can use Disk Management snap-in to assign any letter you want to your flash drives/partitions and it will store the value in the registry.
Any time you boot that OS, it will assign the letters according to the map you've created in its registry.
If you do the same on all of your Windows OSs, you will always get the same letter assigned every time you insert a flash drive, and it will be the same on all the OSs you use.
The only exceptions are partitions containing the "boot" "system" or "page" flags.
You are prevented from altering those letters after the OS installation completes, because information vital to the completion of the boot process using those assignations has also been stored in the registry.
There are ways to work around two of those restrictions, but not "boot" because that's the running OS.
With proper planning before installation, and early housekeeping just afterwards, it's possible (as I have) to have several Windows systems which all map to C as the running system and all shared resources conforming to a common letter map.
It's also possible, by installing in a different way, to keep all of your OSs permanently assigned to a letter other than C, so that the identity doesn't change whether or not it happens to be booted, but that's another story.
FYI There are no disk letters in the BCD.
Partitions in the BCD are referenced by a UID formed from the disk signature and the position of the partition on the HDD.
Because that would be unintelligible to human eyes, EasyBCD translates it into the familiar "disk letter" by referring to the registry map mentioned above for your convenience.
Translation occurs in both directions. When you tell it "C" it looks that up too and converts it into the gibberish UID for you and stores that in the BCD.
That's why the contents of the BCD appear to change between OSs when in fact it's the same BCD with identical content.
 

mqudsi

Mostly Harmless
Staff member
#3
Terry is 100% right, though I suppose it would be possible to extend the drop-down to include some other information aside from the drive letter when adding an entry, much like the Linux drop-down menu displays info about unmounted partitions.
 
#4
You wrote
"the contents of the BCD appear to change between OSs when in fact it's the same BCD with identical content."

Actually, that was my exact problem, that I was trying to address, and I didn't of the above.

I mean, I have two 1TB hdds, each having 4 MBR. first is having w8-32 bit, and w7-32 bit, and second is having w10-64 bit.

So when I logged in to any of them, EasyBCD info appeared to change, and that is what had confused me.

I thought we have to separately specify all this in EasyBCD in each o.s.

but you are actually saying, (or as I understood), we have to specify it correctly in one o.s. only, and the booting sequence will be set for all o.s. that we can change later on.

If so, then it is ok. We can put efforts to specify it correctly in one o.s. and then onward it can control all booting.

Good enough.

Thanks.
--
Rawat
 
#5
However I still feel that showing volume names will help the users recognize the partition correctly and without errors or doubt.

I have named my two hdds as A and B
and then have added 1,2,3,4 for four partitions in each.
and then I have added Windows assigned drive letter that windows defaults to give to them when I log in to w8, which is my primary use o.s.
and then I have added w7-8-10 to whichever partition has bootable o.s.

so I have,
A1CW8 A2DW7 A3E A4F B1GW10 B2H B3I B4J
which are the windows assigned drive letters when I boot in to w8

when I boot into w7, A1CW8 has drive letter D and A2DW7 has drive letter C, rest are unchanged.

but when I boot into w10, B1GW10 has drive letter C, and there is massive change is drive letter assignments.

So, when I run EasyBCd, I also have run windows disk-management from which I check the partition name vis-a-vis drive letter. By reading volume labels, I judge which partition drive letter I have to write in EasyBCd, and that I write.

I am sure many users will be using similar method to decrypt what is missing in EasyBCD.

If I am able to see that w8, w7 and w10 in EasyBCD, it would leave no traces of any miniscule doubt which partition I am referring to in EasyBCD.

I wish EasyBCD will add some info required above so that your users become free of this dependence on windows explorer or windows computer management or windows disk management.

You need not take input of partition name, just display it somewhere. This is how we all recognize our various partitions.

Thanks.
--
Rawat