Triple boot on MBP 2019 (T2)

Question

My goal was to install onto a 2019 Macbook Pro (with a T2 chip) :

OS X Catalina
Windows 10 Pro (1)
Windows 10 Pro (2)

I managed to do so by using Bootcamp for the first Win10, and a bootable USB to install the second Win10.

But when i hold the option key i'm only presented with two choices :

If i select Windows i'll be presented with the Bitlocker Password step and only after that i'll be able to choose between my two Windows 10 installations.

What i would like is to have the two separate Win10 presented after i held the option key like this :

EDIT : Is there any way this can be done on a single internal SSD witouth using rEFInd but ONLY the Startup Manager from Apple ? and how ?

I can post more informations about my setup if needed.

Here is the output of diskutil list :

   /dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI EFI                     314.6 MB   disk0s1
   2:                 Apple_APFS Container disk2         740.0 GB   disk0s2
   3:       Microsoft Basic Data                         129.7 GB   disk0s3
   4:           Windows Recovery                         569.4 MB   disk0s4
   5:                 Apple_APFS Container disk1         25.0 GB    disk0s5
   6:           Windows Recovery                         554.7 MB   disk0s6
   7:                        EFI NO NAME                 314.6 MB   disk0s7
   8:         Microsoft Reserved                         16.8 MB    disk0s8
   9:           Windows Recovery                         554.7 MB   disk0s9
  10:                        EFI NO NAME                 314.6 MB   disk0s10
  11:       Microsoft Basic Data Loisir                  62.0 GB    disk0s11
  12:           Windows Recovery                         554.7 MB   disk0s12
  13:                        EFI NO NAME                 314.6 MB   disk0s13

    /dev/disk2 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +740.0 GB   disk2
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            10.7 GB    disk2s1
   2:                APFS Volume Macintosh HD - Data     25.6 GB    disk2s2
   3:                APFS Volume Preboot                 81.3 MB    disk2s3
   4:                APFS Volume Recovery                528.5 MB   disk2s4
   5:                APFS Volume VM                      1.1 GB     disk2s5

Thanks in advance.

I believe although can't cite a source that this is a firmware change that Apple made to Startup Manager at some point, I've seen this before, it also doesn't honour the name of the partition name either. — unknowndomain, Feb 09 '20 at 22:16
There are tons of existing questions/answers on Triple Booting. See: https://apple.stackexchange.com/search?q=Triple+boot as a start. It’s best if you give some of these a try and if things fail, you edit your question with a specific problem to solve. — Allan, Feb 09 '20 at 22:26
AppleIx as I stated above there is no solution to this, the Windows drive icon is not your real Windows partition, it just passes the boot process over to a different startup manager, this is why @Jivan Pal is suggesting rEFInd. — unknowndomain, Feb 09 '20 at 22:53
@Allan I've already searched the web for more than a week about this issue and was unable to find a specific answer to my question..I already have triple boot working just fine but not the way i'd like it. I don't want to use rEFInd as mentioned but only the Startup manager from apple. — AppleIx, Feb 09 '20 at 22:54
@unknowndomain Oh sorry i misunderstood your answer, so there is no way to achieve this and it means the screenshot i found online and posted above must me from and earlier version of the startup manager ? I'll call Apple tommorow to confirm there is no work around for this.. Thanks you then for your time ;) — AppleIx, Feb 09 '20 at 22:56
@AppleIx correct. I believe this changed around the introduction of APFS (although unrelated). Perhaps someone else can help confirm this? — unknowndomain, Feb 09 '20 at 22:57
Of course there is an answer. I believe you just need to use separate EFI partitions for the Windows boot files for each Windows installation. Although, you seem to have 7 more partitions than you actually need. — David Anderson, Feb 09 '20 at 23:49

David Anderson · Accepted Answer · 2020-02-12T00:02:35.323

You need to use the bcdboot command to create the boot files for each Windows installation in separate EFI partitions.

Note: This answer assume Bitlocker has be disabled. In other words, the answer assumes the Windows NTFS partitions are not encrypted.

Below is an example which closely (but not exactly) matches your situation.

Here, I have already setup two Windows 10 installations where the boot manager, shown below, is used to choose which Windows to boot.

The drive, used in this example, contains your 1st, 2nd, 3rd, 7th, 8th and 11th partitions, albeit the sizes might be different. Also, note the following:

My equivalent to your 3rd partition has the label BOOTCAMP.
My equivalent to your 7th partition is a unformatted and of type Microsoft Basic Data.

For simplicity, I did not include separate recovery partitions. However, creating these partitions for both Windows installations is possible. If using the Boot Camp Assistant to create the first Windows installation, then you probably will need to create and initialize the recovery partition after Windows finishes installing.

Note: A good new question would be how to create the second Windows installation without making such a mess of the partitioning.

Here I will assume you correctly built the Windows USB installer.

Below is the procedure I used to separate the booting of the two Windows installations.

Boot from the Windows 10 USB installer. Proceed until you reach the screen shown below.

At this point, any drivers that may be required to access disk0 have been loaded.

Next, enter the shift+F10 key combination to open a Command Prompt window, as shown below.

Next, use the diskpart, ren and bcdboot commands to separate the booting of the two Windows installations. Below is an example of how I accomplished this. Most of the work involves creating the second EFI partition.

Microsoft Windows [Version 10.0.18362.418]
(c) 2019 Microsoft Corporation. All rights reserved.

X:\Sources>diskpart

Microsoft DiskPart version 10.0.18362.1

Copyright (C) Microsoft Corporation.
On computer: MINWINPC

DISKPART> select disk 0

Disk 0 is now the selected disk.

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    System             315 MB  1024 KB
  Partition 2    Unknown            722 GB   316 MB
  Partition 3    Primary            208 GB   722 GB
  Partition 4    Primary            315 MB   931 GB
  Partition 5    Reserved            16 MB   931 GB
  Partition 6    Primary             68 GB   931 GB

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E   WinInstall   exFAT  Removable     14 GB  Healthy
  Volume 1     C   BOOTCAMP     NTFS   Partition    208 GB  Healthy
  Volume 2                      RAW    Partition    315 MB  Healthy
  Volume 3     D   Loisir       NTFS   Partition     68 GB  Healthy
  Volume 4         EFI          FAT32  Partition    315 MB  Healthy    Hidden

DISKPART> select volume 4

Volume 4 is the selected volume.

DISKPART> assign letter=s

DiskPart successfully assigned the drive letter or mount point.

DISKPART> select volume 2

Volume 2 is the selected volume.

DISKPART> format fs=fat32 label=EFI2 quick

  100 percent completed

DiskPart successfully formatted the volume.

DISKPART> set id=c12a7328-f81f-11d2-ba4b-00a0c93ec93b

DiskPart successfully set the partition ID.

DISKPART> gpt attributes=0x0000000000000000

DiskPart successfully assigned the attributes to the selected GPT partition.

DISKPART> assign letter=t

DiskPart successfully assigned the drive letter or mount point.

DISKPART> detail partition

Partition 4
Type    : c12a7328-f81f-11d2-ba4b-00a0c93ec93b
Hidden  : Yes
Required: No
Attrib  : 0000000000000000
Offset in Bytes: 1000340455424

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
* Volume 2     T   EFI2         FAT32  Partition    315 MB  Healthy    Hidden

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    System             315 MB  1024 KB
  Partition 2    Unknown            722 GB   316 MB
  Partition 3    Primary            208 GB   722 GB
* Partition 4    System             315 MB   931 GB
  Partition 5    Reserved            16 MB   931 GB
  Partition 6    Primary             68 GB   931 GB

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     E   WinInstall   exFAT  Removable     14 GB  Healthy
  Volume 1     C   BOOTCAMP     NTFS   Partition    208 GB  Healthy
* Volume 2     T   EFI2         FAT32  Partition    315 MB  Healthy    Hidden
  Volume 3     D   Loisir       NTFS   Partition     68 GB  Healthy
  Volume 4     S   EFI          FAT32  Partition    315 MB  Healthy    Hidden

DISKPART> exit

Leaving DiskPart...

X:\Sources>ren s:\efi\microsoft\boot\bcd BCD.original

X:\Sources>bcdboot c:\windows /s s:
Boot files successfully created.

X:\Sources>bcdboot d:\windows /s t:
Boot files successfully created.

X:\Sources>exit

After the Command Prompt window closes, you can abort the Windows installation.

References

UEFI/GPT-based hard drive partitions
DiskPart commands
ren
BCDBoot Command-Line Options

Wow thanks you so much for taking the time to answer in such a detailed way..! I tried by two times to use your instructions by i think that my partitioning was too much of a mess in the first place, i then decided to start everything over and just formated the whole disk so that i can start from a fresh start. Is there anyway i could contact you so that i don't make mistakes in the process this time ? Of course i'd be willing to pay you for your time since you seems highly qualified to solve my problem and maybe the whole process would be easier from a fresh install ! — AppleIx, Feb 10 '20 at 16:07
A chat room could be created so we can communicate, if you think this would help. — David Anderson, Feb 12 '20 at 01:43
I had time today to try from scratch and following your instructions it worked flawlessly ! May i ask if you have special degree in IT to have such knowledge in the area ? :) Also is there anyway to tips you ? (btc,paypal or anything) you truly deserve it and saved me a precious time. I saw your answer on another stack question where someone was asking how to modify icons and name presented on the Startup Manager but as i understand it is located in firmware, and only "copies" are located in the filesystem so they cannot be changed ? — AppleIx, Feb 13 '20 at 15:20
I do not know of a way to change the name in the Startup Manager, when the operating system is Windows. However, I know the icon can be changed. Here is an example, where I added text to the existing icon for Windows. You can change both the name and icon for other operating systems (macOS, Linux, etc.). Here is an example of a different icon for macOS. Again, a full answer would probably require a new question. — David Anderson, Feb 14 '20 at 12:54

Triple boot on MBP 2019 (T2)

1 Answers1

References

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