MP 1,1-5,1 Installing Windows 10 in Legacy/BIOS mode in cMP with Boot Camp Assistant

[Macschrauber]

is there not a considerable risk involved making it easy install Windows 10/11 on MacPro5,1?
if remember someone posted here at MacRumors that it is risky to install Windows 10 in UEFI mode OUTSIDE OpenCore since it can corrupt ROM;

i tried to install in Legacy, which didn't function (yet) with the app/script; but it seems there are older version available , that offer only "Windows Install" which i presume would attempt to install UEFI mode? sorry for dumb interjection.

Most important, make a backup of your bootrom. In case something went wrong, you can flash your backup with no certificate back.

If the bootrom has already certificates you can try a deep nvram reset to delete them, if that dont works then I or Alex can clean and repair the mess.

GitHub - Macschrauber/Macschrauber-s-Rom-Dump: A tool for dumping and analysing Mac firmwares. Plus flashing for Mac Pro 4.1 / 5.1

A tool for dumping and analysing Mac firmwares. Plus flashing for Mac Pro 4.1 / 5.1 - Macschrauber/Macschrauber-s-Rom-Dump

github.com

Is a tool for backup, analysing and flashing back. It scans for certificates and much more.

 

[mrkapqa]

Feel free to disregard if this doesn't fit your situation...

For my Mac Pro 5,1: I made a SSD with only one MBR patition. Then performed a legacy install of Windows 10 (1809) from a DVD; upgraded to a later version of Windows 10 then performed an upgrade Windows 11 install on top using RUFUS.

did also use RUFUS for installing win11; but i wonder how you could "upgrade" the Win10 to 11 legacy with the RUFUS method? from what i know, the "upgrade" button would not easily function if you boot from an USB.

 

[719c6]

Feel free to disregard if this doesn't fit your situation...

For my Mac Pro 5,1: I made a SSD with only one MBR patition. Then performed a legacy install of Windows 10 (1809) from a DVD; upgraded to a later version of Windows 10 then performed an upgrade Windows 11 install on top using RUFUS.

I did this without BootCamp. You probably can go straight from Windows 10 1809 to Windows 11, but I did this over a period of time.

Will Rufus install Legacy mode on top of a previous Windows 10? Or install Legacy straight to a new SSD?

 

[aj19876]

I used RUFUS mainly to bypass the hardware requirement check during the upgrade from Windows 10 to 11.

I think RUFUS has an option for a "legacy" (CSM) mode. I didn't try, so I don't know if you can do a direct Windows 11 legacy install this way.

Sorry for the incomplete responses Perhaps someone else can add to this...

 

[startergo]

I would recommend starting another thread for Rufus. You need Windows for it in the first place. Plus it is just an ISO installer. Here we are discussing legacy Windows install either through a Bootcamp or any tool that can create legacy Windows drive from macOS.

 

[Sergey-Galan]

@Sergey-Galan thank you but did not yet function did not function on my installation here runnning macOS Mojave (
System Integrity Protection status: disabled)

the program tried both with windows 10 and afterwards windows 7 iso 64bit to do a Windows Legacy Install

but would stop at around 22-21 seconds saying "Bootloader complete"

the HDD is 1tb prepared with GUUID and Fat32.


maybe the tuxera NTFS program is making trouble?
have given it the required approval, but program has made issue in the past with USB sticks losing the content after formatting them in NTFS.


EDIT: i uninstalled the NTFS by Tuxera, but the result is moreless the same: "Bootloader complete" status message, but very few files written onto Test Partition.

Thank you very much for testing. It's my fault, please try again with a new option.

 

[Sergey-Galan]

simple glitch:

I cannot configure partition number 1 for MBR on single disk

The disk should only have a GUID Partition Map. But if there is a need, I can add the ability to install Windows on the MBR.
Format the disk in GUID Partition Map and the program will do the following:
1. Makes the drive hybrid.
2. Makes the section active.
3. Four-byte Windows disk signature from the MBR.
4. Writes a Windows MBR to the block device of the target disk.
5. Writes a Windows PBR to the block device of the system partition.
This is all that is needed and there is no need to do it manually.
To perform the third point, there is a need to turn off the entire disk, according to this, the disk cannot be systemic, since Mac OS will not allow it to disable it. But the option is possible when the Windows Legacy Boot is already installed on the disk with the system, or to temporarily install the Mac OS on the flash drive and install Windows on the main disk from it.

 

[tsialex]

But if there is a need, I can add the ability to install Windows on the MBR.

This will be very useful with Mac Pros, for a series of reasons (CSM implementation related) a MacPro5,1 works best with the simplest possible Windows install - a dedicated SATA disk for Windows, formatted with MBR.

 

[Sergey-Galan]

This will be very useful with Mac Pros, for a series of reasons (CSM implementation related) a MacPro5,1 works best with the simplest possible Windows install - a dedicated SATA disk for Windows, formatted with MBR.

OK, I'll do it

 

[Macschrauber]

Thank you very much for testing. It's my fault, please try again with a new option.

6.1.4 has a bug (same procedure works for 6.1.3):

after pressing the Install button:

diskutil list disk2
/dev/disk2 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk2
   1:                        EFI ⁨EFI⁩                     209.7 MB   disk2s1
   2:       Microsoft Basic Data ⁨Windows⁩                 1000.0 GB  disk2s2

the filename of the image: 19044.1288.211006-0501.21h2_release_svc_refresh_CLIENT_LTSC_EVAL_x64FRE_de-de.iso

 

[Sergey-Galan]

6.1.4 has a bug (same procedure works for 6.1.3)

Or your image is not original and needs a different approach. The original one has this path /V*/*/sources/install.* The name of the mounted image has “DV” and the correct path, otherwise look directly for the WIM or ESD file. Or on version 6.1.4 they tried to run the option from version 6.1.3 “Windows Install”, select “Install Windows legacy boot”.

 

[mrkapqa]

@Sergey-Galan thanks with the new script it came close to Finish , but it would not start the Windows 7 partition (Legacy), it would just "blink" when booting from the Partition > actually, in MacOS the TEST partition is shown as bootable in Startup Disk Panel, but when rebooting, or pressing Alt to choose BootPartition, the Windows partition is not bootable;

maybe another step is needed?

 

[Macschrauber]

6.1.4 has a bug (same procedure works for 6.1.3):
View attachment 2384380
after pressing the Install button:
View attachment 2384382

diskutil list disk2
/dev/disk2 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk2
   1:                        EFI ⁨EFI⁩                     209.7 MB   disk2s1
   2:       Microsoft Basic Data ⁨Windows⁩                 1000.0 GB  disk2s2

the filename of the image: 19044.1288.211006-0501.21h2_release_svc_refresh_CLIENT_LTSC_EVAL_x64FRE_de-de.iso[/CODE]

it was the same image, also downloaded recently.

For some reason, after selecting it Windows Install became Windows Install UEFI and Windows Install legacy, after selecting it once. Do you store a preferences file somewhere? Maybe it got confused by using 6.1.3 and 6.1.4

Now it works with the image, after selecting once Windows Install UEFI


look at the button text, the last time I used the 6.1.4 App it was Windows Install


And btw: I see you added: Legacy Install. Very nice, will test it soon. But I still cannot select Partition number 1. This is what we use when we pop up a single Sata disk with MBR in a Mac Pro, dedicated for Legacy Windows.

 

[Sergey-Galan]

And btw: I see you added: Legacy Install. Very nice, will test it soon. But I still cannot select Partition number 1. This is what we use when we pop up a single Sata disk with MBR in a Mac Pro, dedicated for Legacy Windows.

I'm working on MBR. Try the hybrid for now, that's what Bootcamp does.

@Sergey-Galan thanks with the new script it came close to Finish , but it would not start the Windows 7 partition (Legacy), it would just "blink" when booting from the Partition > actually, in MacOS the TEST partition is shown as bootable in Startup Disk Panel, but when rebooting, or pressing Alt to choose BootPartition, the Windows partition is not bootable;

maybe another step is needed?

Can you try again and send me the log?

 

[mrkapqa]

Can you try again and send me the log?

tried again, but this time it would function with Windows 10 image;
will send you the log if you still interested tomorrow; will try some more with windows 7 then, maybe the image was not a lucky one

 

[startergo]

Windows 7 is a tricky one. Depends on where you are trying to load it. Also it is a little weird with the legacy driver in the vBios with MBR boot. Some cards may not load the boot screen or even refuse to boot. I would say to prevent any other issues messing with the booting process to stick with Windows 10/11 at least until it confirms the proper legacy boot. Also it is a good idea to place the Bootcamp drivers folder structure created by the Bootcamp software to the drive or use the USB created by Bootcamp along with the Windows installation. Without bootcamp drivers most of the time the boot fails.

 

[Macschrauber]

I got it booting legacy Windows 10 a bit when installing to a gpt disk in legacy mode.

Apple Boot Picker showed Windows, could start it, but got a bluescreen complaining about wrong bcd codes.

Tried a bcd code repair with hard disk toolkit, but no cure.

 

[startergo]

There are 2 programs for correcting the BCD from macOS and linux.

GitHub - jpz4085/BCD-SYS: Setup the Windows BCD and boot files from Linux or macOS.

Setup the Windows BCD and boot files from Linux or macOS. - jpz4085/BCD-SYS

github.com

Fix various issues and add support for hybrid MBR scheme. · jpz4085/BCD-SYS@b9e9276

1. Fix detection of BIOS boot files for older Windows versions. 2. Fix detection of NTFS write access to system partitons on macOS. 3. Fix detection of filesystems when setting MS-DOS file attribut...

github.com

GitHub - jpz4085/ms-sys: Program for writing Microsoft compatible and other boot records. Linux, BSD and Mac supported.

Program for writing Microsoft compatible and other boot records. Linux, BSD and Mac supported. - jpz4085/ms-sys

github.com

 

[startergo]

Thank you very much for testing. It's my fault, please try again with a new option.

Although it detects hybrid partition it still Proposes and installs Windows UEFI:

@Sergey-Galan on a hybrid partition it should not install bootx64.efi anywhere. That is the whole purpose of the hybrid MBR partition. Yes for sure on boot it will first try to load bootx64.efi which is going to load Windows in UEFI rather than MBR mode and write certificates to the NVRAM, which is what we are trying to avoid.

 

[startergo]

I even set the partition to Legacy BIOS bootable, but still it offers Windows UEFI:

Expert command (? for help): i
Partition number (1-4): 3
Partition GUID code: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 (Microsoft basic data)
Partition unique GUID: D9A31E31-D109-457F-83A1-BB4461D90B26
First sector: 581964952 (at 277.5 GiB)
Last sector: 849491919 (at 405.1 GiB)
Partition size: 267526968 sectors (127.6 GiB)
Attribute flags: 0000000000000004
Partition name: 'Windows'

 

[mrkapqa]

tried again today with Windows 7 image , changed image from "en_windows_7_ultimate_with_sp1_x64_dvd_u_677332" to "de_windows_7_professional_with_sp1_x64_dvd_u_676919" and now the installation would start as normal, but stop sadly halfway through the process with error like "the starting configuration could not be actualised. please start ..."
with windows 10 image the legacy installation mode went trough flawless, very pleased.

the HDD has already MacOS partition (Mavericks) and i split the HDD in half, and formatted the latter half as FAT-32.
After i installed Win10 successfully, i re-formatted the second half of the HDD again in Mojave from NTFS to FAT-32 to prepare for a new installation of Windows 7; but Apple Boot Picker would still recognize the partition as "Windows" at startup, which i found odd.

@Sergey-Galan here are the log(s), maybe there can be found something that can hint to why the Windows 7 installation fails halfway through.


EDIt: error goes like "Windows could not update the computer's boot configuration. Installation cannot proceed".

 

[startergo]

I installed Windows 10 in Legacy mode and after booting got this:

sudo fdisk /dev/disk8
Disk: /dev/disk8    geometry: 30401/255/63 [488397168 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE    0   0   2 -   25 127  14 [         1 -     409639] <Unknown ID>
 2: AF   25 127  15 - 1023 254  63 [    409640 -  243862672] HFS+       
*3: 07 1023 254  63 - 1023 254  63 [ 244535296 -  243599360] HPFS/QNX/AUX
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

 sudo gdisk /dev/disk8
GPT fdisk (gdisk) version 1.0.9

Warning: Devices opened with shared lock will not have their
partition table automatically reloaded!
Partition table scan:
  MBR: hybrid
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with hybrid MBR; using GPT.

Command (? for help): p
Disk /dev/disk8: 488397168 sectors, 232.9 GiB
Sector size (logical): 512 bytes
Disk identifier (GUID): 3395102C-58C4-4F72-8AF0-82ABCE1D9A56
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 488397134
Partitions will be aligned on 8-sector boundaries
Total free space is 525469 sectors (256.6 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              40          409639   200.0 MiB   EF00  EFI System Partition
   2          409640       244272311   116.3 GiB   AF00  SNow Leopard
   3       244535296       488134655   116.2 GiB   0700  BOOTCAMPSL

Command (? for help): ?
b    back up GPT data to a file
c    change a partition's name
d    delete a partition
i    show detailed information on a partition
l    list known partition types
n    add a new partition
o    create a new empty GUID partition table (GPT)
p    print the partition table
q    quit without saving changes
r    recovery and transformation options (experts only)
s    sort partitions
t    change a partition's type code
v    verify disk
w    write table to disk and exit
x    extra functionality (experts only)
?    print this menu

Command (? for help): i
Partition number (1-3): 3
Partition GUID code: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 (Microsoft basic data)
Partition unique GUID: B7721A67-42C3-43BF-B0C9-8C2E01F4FC02
First sector: 244535296 (at 116.6 GiB)
Last sector: 488134655 (at 232.8 GiB)
Partition size: 243599360 sectors (116.2 GiB)
Attribute flags: 0000000000000000
Partition name: 'BOOTCAMPSL'

 

[startergo]

Command (? for help): x

Expert command (? for help): ?
a    set attributes
b    byte-swap a partition's name
c    change partition GUID
d    display the sector alignment value
e    relocate backup data structures to the end of the disk
f    randomize disk and partition unique GUIDs
g    change disk GUID
h    recompute CHS values in protective/hybrid MBR
i    show detailed information on a partition
j    move the main partition table
l    set the sector alignment value
m    return to main menu
n    create a new protective MBR
o    print protective MBR data
p    print the partition table
q    quit without saving changes
r    recovery and transformation options (experts only)
s    resize partition table
t    transpose two partition table entries
u    replicate partition table on new device
v    verify disk
w    write table to disk and exit
z    zap (destroy) GPT data structures and exit
?    print this menu

Expert command (? for help): a
Partition number (1-3): 3
Known attributes are:
0: system partition
1: hide from EFI
2: legacy BIOS bootable
60: read-only
62: hidden
63: do not automount

Attribute value is 0000000000000000. Set fields are:
  No fields set

Toggle which attribute field (0-63, 64 or <Enter> to exit): 2
Have enabled the 'legacy BIOS bootable' attribute.
Attribute value is 0000000000000004. Set fields are:
2 (legacy BIOS bootable)

Toggle which attribute field (0-63, 64 or <Enter> to exit): w

Expert command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/disk8.
Warning: Devices opened with shared lock will not have their
partition table automatically reloaded!
Warning: The kernel may continue to use old or deleted partitions.
You should reboot or remove the drive.
The operation has completed successfully.

sudo gdisk /dev/disk8
GPT fdisk (gdisk) version 1.0.9

Warning: Devices opened with shared lock will not have their
partition table automatically reloaded!
Partition table scan:
  MBR: hybrid
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with hybrid MBR; using GPT.

Command (? for help): i
Partition number (1-3): 3
Partition GUID code: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 (Microsoft basic data)
Partition unique GUID: B7721A67-42C3-43BF-B0C9-8C2E01F4FC02
First sector: 244535296 (at 116.6 GiB)
Last sector: 488134655 (at 232.8 GiB)
Partition size: 243599360 sectors (116.2 GiB)
Attribute flags: 0000000000000004
Partition name: 'BOOTCAMPSL'

Even after setting the Flag Legacy Bios bootable still ended up with the same error on boot.

 

[mrkapqa]

I installed Windows 10 in Legacy mode and after booting got this:

View attachment 2384670



i did use a official Windows 10 Iso 22H2 maybe if you use 23H2/24H2 you might have less luck?[/CODE]

 

[Sergey-Galan]

I got it booting legacy Windows 10 a bit when installing to a gpt disk in legacy mode.

Apple Boot Picker showed Windows, could start it, but got a bluescreen complaining about wrong bcd codes.

Tried a bcd code repair with hard disk toolkit, but no cure.

Most likely, reged doesn’t have time to work, this happened to me randomly, I added 2 seconds of shutter speed and it stopped, I’ll figure it out, but it’s random, try again)))