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Testing UEFI booting on a only Bios PC

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#1 alacran

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Posted 23 May 2021 - 12:00 AM

On some of the last Posts in the topic GRUB4DOS for UEFI the user zammibro was talking about UEFI booting on a only Bios PC and I said it was not possible as Bios programs do not have the required code and internal drivers to boot on UEFI environment on this Post, but our friend Wonko made a very simple and clear explanation of how Clover works in order to UEFI boot on a only Bios (or CSM) PC on this Post.  And also mentioned some links to AIO_Boot pages with additional info on this Post.

 

Well, let me tell you I have used AIO_Boot since very long time ago, in fact I'm the Spanish translator, but never used Clover before as I had the idea it was only a tool to boot Apple OS on a PC.

 

Then I decided to run some test to see if Clover was really capable to UEFI booting on a only Bios PC a Windows installed on our internal HD, (MB used for this tests is Gigabyte GA-G41MT-S2 v1).

 

I went to AIO_Boot download page and downloaded last version, and installed it on a USB device as usuall.

 

Then ran the AIOCreator.exe to integrate my Win10XPE_x64 and my 7pe_amd64_E on AIO-Boot USB device, after booting from it both booted fine as UEFI.  To make sure about this I ran BootIce v1.3.3.2 2015-02-16 from both WinPEs and opened UEFI Tab, and the option to edit the UEFI boot entries was available.   It was a little weird as we all know 7x64 is not fully capable to boot on UEFI environment.  Then this test demonstrated Clover is capable to provide the required code and internal drivers to boot on UEFI environment a Windows PE.  But it didn't work when I tried to UEFI boot a Win10 Pro x64 installed on my internal HD.

 

In order to keep safe my multiboot on the internal HD, I switched off the PC and connected an spare Sata drive to run the following tests, booted Win10XPE_x64 from AIO-Boot to repartition and format the drive (MBR partitioned), I made a 5 GB first active primary partition FAT-32 (to have espace just in case but 1 GB should be enough), and a 40 GB NTFS second primary partition and cloned into it the Win10 Pro x64 drive/partition from the internal HD, also made an extended partition on the rest of the drive and cloned on a logical partition my Programs drive/partition to have available all my tools, then I created all bootable files/folders by command line on the FAT-32 first partition:

 

 

bcdboot C:\Windows /s S: /f ALL
 

Where:

 

C:\Windows = Where Win is installed (just change C: for the drive letter where Windows is installed as seen on the WinPE)

/s S:: = Where the boot files/folders will be installed (just change S: for the letter of your System Reserved partition as seen on the WinPE)

/f ALL Installs MBR + UEFI boot files/folders

 

And switched off the PC again to disconnect the other HD.

 

Booted again from AIO_boot USB stick, and this time as the standard EFI folder with all files/folders to UEFI boot the Win10 Pro x64 OS is available on FAT-32 partition the system was able to boot fine on a Clover emulated UEFI environment.

 

See attached photos of Clover options selected and also the probe by means of BootIce that it was really booted on UEFI environment.

 

Then I have to recognize that it is in fact possible to UEFI boot on a only Bios PC, by means of AIO_boot and Clover.

 

alacran

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#2 alacran

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Posted 23 May 2021 - 12:50 AM

Forgot to comment I edited as usuall both BCDs to use text mode during boot, as it is preferable on multiboot environments.

 

Also forgot to mention this two options from Clover help menu (F1) that are very usefull:

 

F10 - make a picture in AIO drive:\EFI\CLOVER\misc

Space Bar - Detailed Option info with more options if available.

 

On my next test I will include AIO_Boot into FAT-32 bootable partition to try to UEFI boot without the need of the USB stick, I already know if I add an entry pointing to \AIO\grub\grub2win to Bios BCD located on Boot folder by means of BootIce I can call and load AIO_Boot grub2 menu.

 

alacran

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#3 Guest_AnonVendetta_*

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Posted 23 May 2021 - 12:58 AM

I think your only options here are Clover or UEFI DUET. I had created a topic here a few years ago regarding DUET on my old laptop. But on the newer PC i currently have, it's iffy at best, sometimes it boots (from a flash drive), other times not. It also doesnt seem to recognize any of my NVMe SSDs,only my SATA SSDs. And even then, not always.

It's been awhile since I tried Clover. I know it can be used for pure native UEFI mode, as well as emulated UEFI on a BIOS only system. It even has a modified version of DUET built in, accessible from the main menus (can't remember exactly where). There are detailed instructions on their wiki. Clover seems to be mostly Apple Mac oriented, but it works on non Apple PCs too.

My current PC is fully UEFI/Secure Boot compatible,along with supporting legacy CSM, so I dont need to use UEFI emulation anymore. I was just curious whether DUET would work as well on newer hardware.

Edit: I also forgot to mention that you can try what's known as "UEFI on MBR". Many dont realize that you actually can boot a UEFI Windows on/from a disk that has an MBR partition table. No Clover or DUET. I actually tried this setup once, but ultimately abandoned it. Just Google for "uefi on mbr" or "windows uefi on mbr" if you want more details on how to set it up. Of course, you'll be limited to 4 primary partitions, or 3 primaries and an extended containing logicals. If you decide to try this, do NOT put the C drive in a logical partition, Windows will simply hang without errors and not boot (this is what happened when i tried it). C drive must be in a primary, other partitions can be logical. You'll also need to create a FAT32 UEFI system partition on your MBR disk, this partition must also be primary.

#4 alacran

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Posted 23 May 2021 - 02:34 PM

Thanks for the info, and I appreciate the good intention, but if you read carefully the first post, you will notice I'm already running this tests from a MBR formated HD, were first primary active partition is FAT-32 and second primary partition is NTFS where the 10x64 OS resides.

 

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#5 alacran

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Posted 23 May 2021 - 03:32 PM

Now I will comment about my last tests trying to avoid the need of the AIO-Boot USB device, integrating it into internal HD on the FAT-32 bootable partition.

 

First test copying AIO_Boot USB device content to the FAT-32 bootable partition.

 

It was a complicated procedure as there are allready two BCD files on bootable partition and AIO_Boot also has its own, so it was necessary to be carefull to avoid overwriting them, and latter edit as required, I adedd an entry pointing to \AIO\grub\grub2win to Bios BCD located on Boot folder by means of BootIce and I can call and load AIO_Boot grub2 menu.  From it I selected the entry for Clover Boot manager but it didn't load, only got a blinking cursor; if loading the grub4dos menu.lst Clover entry just loads the boot options into Boot\BCD (Bios mode).

 

Second test creating an AIO.ima file and booting it by means of grub4dos.

 

This simplifies the procedure to integrate AIO_Boot and also the edition of BCD files.

After creating a 241 MB AIO.ima file I copied it to bootable partition, also added grldr.mbr, grldr and made a menu.lst on the root of same partition, and made an entry in Boot\BCD to load grldr.mbr, used following entries on menu.lst:

 

 

iftitle [if exist /AIO.ima] AIO_Boot Filedisk - /AIO.ima
map /AIO.ima (hd)
map --hook
root (hd-1,0)
configfile /AIO/Menu/Grub4dos.lst

iftitle [if exist /AIO.ima] AIO_Boot Ramdisk - /AIO.ima
map --mem /AIO.ima (hd)
map --hook
root (hd-1,0)
configfile /AIO/Menu/Grub4dos.lst

 

Both load very fine the /AIO/Menu/Grub4dos.lst, from it is very easy to chainload to grub2 menu and select the entry for Clover Boot manager but same thing it didn't load, only got a blinking cursor; if loading Clover from the grub4dos menu.lst entry just loads the boot options into Boot\BCD (Bios mode), as on previous test.

 

Then so far I was able to integrate the content of the AIO_Boot USB device into the bootable partition, and sucessfully load AIO_Boot menus, but Clover (legacy) does not run this way. 
 

alacran



#6 Guest_AnonVendetta_*

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Posted 23 May 2021 - 08:10 PM

I looked at the screenshots only, it did look like you were already using UEFI on MBR. But the way I set it up, no 3rd party softwares/bootloaders are required. I only used GParted in Linux to partition the disk. Then installed Windows via commands (i already knew that installer GUI wouldnt work for this). Windows booted normally, which was unexpected.

#7 Wonko the Sane

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Posted 24 May 2021 - 09:26 AM

@alacran

http://reboot.pro/to...-from-grub4dos/

 

:duff:

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#8 relynx

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Posted 24 May 2021 - 05:55 PM

[SCRIPT_1] This is also a handy script to make a Clover boot device (Link).
Short run through to EFI boot Win10 and MBR boot Ubuntu 20.4 via Clover on a MBR-boot-only PC:

PREREQUISITE:
* [FOLDER_1] EFI install of Ubuntu 20.04. Needed is the folder "/EFI/ubuntu/"
* My USB drive is "/dev/sdb". Adjust to your needs accordingly.

1. Partitioning with gdisk (see Rod's Walkthrough for details).

$ sudo gdisk /dev/sdb
[sudo] password for relynx:
GPT fdisk (gdisk) version 1.0.5

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk /dev/sdb: 234441648 sectors, 111.8 GiB
Model: SSD Sata III    
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): 5FF62CBC-432F-4C33-937E-B41F9A3579E4
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 234441614
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  EF00  USB_ESP
   2         2099200         2131967   16.0 MiB    0C01  Microsoft reserved
   3         2131968        54560767   25.0 GiB    0700  USB_WIN10_MBR
   4        54560768       106989567   25.0 GiB    0700  USB_WIN10_EFI
   5       106989568       158945279   24.8 GiB    0700  USB_NTFS_DATA
   6       158945280       175722495   8.0 GiB     0700  USB_NTFS_SWAP
   7       175722496       196694015   10.0 GiB    8300  USB_UBUNTU_MBR
   8       196694016       217665535   10.0 GiB    8300  USB_UBUNTU_EFI
   9       217665536       234441614   8.0 GiB     8200  USB_USWAP

Command (? for help):

2. Install EFI Windows 10 to USB_WIN10_EFI partition.
3. [FOLDER_2] Backup /EFI/Microsoft/ to somewhere.
4. MBR install Ubuntu to USB_UBUNTU_MBR partition.
5. Execute [SCRIPT_1]. In my case with parameters: "/dev/sdb" and "/dev/sdb1" (USB_ESP)
6. Copy [FOLDER_1] and [FOLDER_2] to "/USB_ESP/" aka "/dev/sdb1/".
7. Adjust "/EFI/ubuntu/grub.cfg" to point to USB_UBUNTU_MBR partition.
9. boot USB drive /dev/sdb on a MBR-boot-only PC.



#9 Guest_AnonVendetta_*

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Posted 24 May 2021 - 10:11 PM

If the UEFI booting is only being emulated, then is it truly UEFI booting? It's actually just legacy booting, pretending to be UEFI. Regardless of what the booted OS "believes".

#10 alacran

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Posted 24 May 2021 - 10:36 PM

If the UEFI booting is only being emulated, then is it truly UEFI booting? It's actually just legacy booting, pretending to be UEFI. Regardless of what the booted OS "believes".

 

That's a good question, IMHO in a strict sence we make the OS "belive" it is booting on a real UEFI environment, same applies to all programs we run.

 

EDIT: But the UEFI environment is emulated by Clover and it is in fact available there, as we can confirm by means of BootIce. (I assume the Clover emulated UEFI environment is loaded on Ram).

 

In fact once the OS boots it acts the same on a Bios or on a UEFI environment, and for the user there is no advantage in booting it one way or the other.

 

alacran



#11 alacran

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Posted 24 May 2021 - 11:05 PM

 

Thanks for this link Wonko, as I can see our good fellow steve6375 worked with this subject long time ago on May/2014. Basically he is using grub4dos + Clover on his topic. I'm sorry I didn't know about it before.

 

EDIT-1: When going to that topic I saw I read it at that time, there is a like from myself on first post, it seems I forgot I read it.

 

People interested in reading steve6375 topic please see: UEFI Boot from grub4dos,

 

EDIT-2: steve6375 is also using a USB stick to boot, and his procedure is a few more complicated (I would say for advanced users only) than using an AIO_Boot USB stick, as on the procedure mentioned on the first post of this topic.

 

Then so far a USB stick is still required.

 

Alacran



#12 alacran

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Posted 25 May 2021 - 01:42 AM

@ relynx

 

It seems that procedure requires a GPT partitioned internal HD and/or the use of a GPT partitioned USB device and also seems basically that procedure is made on Linux.

 

Thanks for your info, I appreciate your contibution to this topic.  It may be usefull for some users using Linux.

 

My initial goal here was boot an already installed Win10 Pro x64 on a MBR partitioned disk, trying to make the minumum changes posible and make all on Windows.  And it was achieved since the fist post of this topic by means of AIO_Boot + Clover, and booting from a WinPE integrated previously into AIO_Boot, just reformat bootable partition as FAT-32 and rebuilding boot files/folders (this time including EFI folder) on command line as follows:

 

 

bcdboot C:\Windows /s S: /f ALL
 

Where:

 

C:\Windows = Where Win is installed (just change C: for the drive letter where Windows is installed as seen on the WinPE)

/s S:: = Where the boot files/folders will be installed (just change S: for the letter of your System Reserved partition as seen on the WinPE)

/f ALL Installs MBR + UEFI boot files/folders

 

But after testing this was sucessfull, I wanted to go further and try to avoid the use of an additional USB device, integrating AIO_Boot USB device content into bootable partition, this approach was tested on post No. 5

 

But as said there:

 

Then so far I was able to integrate the content of the AIO_Boot USB device into the bootable partition, and sucessfully load AIO_Boot menus, but Clover (legacy) does not run this way.

 

alacran



#13 alacran

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Posted 25 May 2021 - 06:59 AM

Well, it seems my precaution to make the FAT-32 partition of 5 GB (just in case) allowed me to run some more tests:

 

Installing AIO_Boot on second primary FAT-32 partition:

 

Booted Win10XPE_x64 from AIO_Boot and reduced the FAT-32 partition (where all boot files folders reside) to 2 GB.

 

In the remaining espace (3 GB) I created another FAT-32 partition and copied there the content of AIO_Boot USB stick.

 

Edited my menu.lst located on first FAT-32 active partition and made this entry:

 

 

iftitle [if exist (hd0,1)/AIO/grub/i386-pc/core.img] AIO_Boot - (hd0,0)/AIO/grub/i386-pc/core.img
find --set-root /AIO/grub/i386-pc/core.img
kernel /AIO/grub/i386-pc/core.img

 

To load/run AIO_Boot grub2 legacy from (hd0,1), located on second FAT-32 partition, it ran fine but againg it was unable to run/load CloverLegacy, same blinking cursor is all I got as before.

 

 

Installing AIO_Boot on first primary FAT-32 partition:

 

(Sucessfull boot on Clover emulated UEFI environment running it from grub2 or grub4dos).

 

Booted Win10XPE_x64 from AIO_Boot and formated second primary FAT-32 partition and renamed it as START, and rebuilded all Windows boot files/folders in command line, formated the first FAT-32 partition renamed it to AIO and copied there all the content of my AIO_Boot USB stick, and ran from the AIO HD partition AIOCreator.exe, and installed from it grub2 and Clover, now MBR is grub2 after this.

 

Rebooted the PC and it booted directly to AIO_Boot menu (gub2 legacy), when selecting to boot Clover Bootmanager on the menu, now finally it loads/runs fine and it loads bootmgfw.efi and the \EFI\Microsoft\Boot\BCD fine, and the OS booted fine on Clover emulated UEFI environment, in fact I'm writing from it right now, also if from grub2 legacy menu I load grub4dos menu, it also loads/runs fine CloverLegacy and loads the emulated UEFI environment and the OS boots fine on UEFI too.

 

I have to admit doing it this way wasn't my favorite option, but it was the only remaining alternative I found to avoid the use of an additional USB device to boot in Clover emulated UEFI environment.

 

Of course the user can select from AIO_Boot menu (gub2 legacy) to boot the OS on Bios mode.

 

Summary:

 

First primary FAT-32 active partition to content AIO_boot files/folders. Used space without any WinPE is 118 MB, minimum recommended size 150 MB

 

Second primary FAT-32 partition to content Windows boot files/folders. Used space for only Windows boot files/folders about 25 MB, minimum recommended size 64 MB (you can't make a FAT-32 smaller in Windows).

 

Third primary NTFS partition to content the OS, minimum recommended size in accordance with Windows recommendations for respective OS.

 

Rest of HD an extended partition with several NTFS formated logical partitions.

 

 

Pros:

 

None, In fact once the OS boots it acts the same on a Bios or on a UEFI environment, and for the user there is no advantage in booting it one way or the other.

 

Cons:

 

Doing it this way requires 3 partitions to boot an OS and on a MBR partitioned disk there is only one remaining partition available to create an extended partition, with several logical partitions into it, where we can have our documents and  portable programs, or may install other OSs but they will boot only in Bios mode, as to boot on UEFI mode the OS has to be installed on a primary partition, of couse the user can prefer to make a fourth primary partition and not an extended partition in this case, but this way is not very easy to share some documents and portable programs between each other OS.

 

Conclusion:

 

There is no advantage in UEFI booting a only Bios PC, If the user really wants to boot on UEFI environment for some reason, It seems it is better to use an auxiliary USB device as on first post, than the approach on this post.

 

EDIT: From new info on Post No. 15

 

To boot without an auxiliary USB stick, only two primary partitions FAT-32 formated are required, first to contain AIO_Boot files, and second to contain Windows boot files/folders, and the OS, VHD or WinPE boot very fine from a logical partition when using a MBR formated disk. I think this is due to the fact that just after loading the Clover emulated UEFI environment when I select "Boot Microsoft EFI boot from START", the Windos boot process takes the contol and then it can boot a OS, a VHD or Wim file from any partition, as it is usually capable to boot.

 

But I have to admit this topic has being an interesting exercise.

 

alacran



#14 alacran

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Posted 25 May 2021 - 10:40 AM

AFAIK on Clover emulated UEFI environment if booting from a MBR formated disk, we can only boot from primary partitions.

 

EDIT: From new info on Post No. 15

 

Conclusion:

 

To boot without an auxiliary USB stick, only two primary partitions FAT-32 formated are required, first to contain AIO_Boot files, and second to contain Windows boot files/folders, and the OS, VHD or WinPE boot very fine from a logical partition when using a MBR formated disk. I think this is due to the fact that just after loading the Clover emulated UEFI environment when I select "Boot Microsoft EFI boot from START", the Windos boot process takes the contol and then it can boot a OS, a VHD or Wim file from any partition, as it is usually capable to boot.

 

As we all know MBR formated disks only allow 4 primary partitions or 3 primary and a extended partition with several logical partitions into it.

 

But I think one way to overcome this limits could be using VHDs, I will test this and let you know on my next Post.

 

EDIT-2: We are not forced to use VHDs according to the info on EDIT-1

 

alacran



#15 alacran

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Posted 25 May 2021 - 03:01 PM

Test Filedisk booting from VHD located on third primary partition:

To make a fast test, just copied my Mini-10x64.vhd into third primary partition and created its entries on Boot\BCD and on EFI\Microsoft\Boot\BCD by means of UEFI_MULTI made by our fellow wimb, it booted fine as expected.

 

Test Filedisk booting from VHD located on fist logical partition:

 

As every time AIO_Boot loads Clover, when I select to "Boot Microsoft EFI boot from START" (the name I gaveto the second FAT-32 primary partition where my Windows boot files/folders reside) it shows me all available booting options I have added to EFI\Microsoft\Boot\BCD, so I decided to also copy same VHD renamed to Mini-10x64-4.vhd  (4 for fourth partition, the first logical partition), as I started thinking it could also boot from it, and just created the required entries on BCD files by means of UEFI_MULTI, and it booted very fine on Clover emulated UEFI environment, also tested booting from same partition my Win10XPE_x64.wim and it booted fine too.

 

Conclusion:

 

To boot without an auxiliary USB stick, only two primary partitions FAT-32 formated are required, first to contain AIO_Boot files, and second to contain Windows boot files/folders, and the OS, VHD or WinPE boot very fine from a logical partition when using a MBR formated disk. I think this is due to the fact that just after loading the Clover emulated UEFI environment when I select "Boot Microsoft EFI boot from START", the Windos boot process takes the contol and then it can boot a OS, a VHD or Wim file from any partition, as it is usually capable to boot.

 

I will edit my previous post to mention this info as IMHO it is good info for people interested in booting in UEFI environment on only Bios PC.

 

Attached two photos showing my current partitions during this tests and the Clover screen

 

alacran

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#16 alacran

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Posted 25 May 2021 - 07:04 PM

Tests Ramdisk booting from VHDs located on a logical partition:

As on previous Post during making the Test Filedisk booting from VHD located on fist logical partition, I created the required entries on both BCD files by means of UEFI_MULTI by wimb, it also added grub4dos.mbr to \Boot\BCD (Bios mode) and also grld.mbr, grld and menu.lst on the root of second FAT-32 partition, with the respective entries on menu.lst to Ramboot from the VHD, then when booting and the grub2 legacy menu is loaded, selecting option 5 Boot Windows on Hard Disk I arrive to \Boot\BCD menu and selecting from it Grub4dos Menu then the menu.lst is loaded, and next step is select the VHD Ramboot option, and it Rambooted flawlessly.

Then I went further and copied to a logical partition my 1 GB Mini-10x64-WB.vhd (Wimboot mode installed) and its respective WIM file into Wimboot folder, and this time used VHD_WIMBOOT by wimb, to repair the link between both and create the respective entries on both BCD files and also the entry on menu.lst, and doing same as on previous paragraph this time selected the Wimboot VHD Ramboot option, and it also Rambooted very fine.

NOTE-1: This VHDs are Rambooting on Bios environment as they were loaded by means of grub4dos, not the new grub4dos for UEFI (or as they also use to call it: G4E)

NOTE-2: Just to clarify this:

  • Bootable Windows partition on Bios machines MBR partitioned is the first active primary partition NTFS formated and it's named by Windows: System.
  • Bootable Windows partition on UEFI machines GPT partitioned is FAT-32 formated and it's named by Windows: EFI
  • On this test Bootable Windows partition on Bios machines MBR partitioned is secondary partition (non active) FAT-32 formated and I named it as START, to clearly diferenciate it from the other two, as it contains Bios and UEFI boot files/folders and it is the second primary partition.
  • On this tests on Bios machines MBR partitioned the first active primary partition is FAT-32 formated and as it is used to contain AIO_Boot files/folders, the logical name used is AIO.

 

alacran



#17 alacran

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Posted 25 May 2021 - 10:36 PM

JFYI

 

From: https://www.aioboot....loader-windows/

 

Clover Legacy Installer

.....

If Clover reports “boot0ss: Error“, try Active for the FAT32 drive where you installed Clover.

......

 

So this means that running CloverLegacy from a non-active partition is a known cause of execution failure.

 

This explains why if booting with Windows Bootmgr from the Active partition and chainloading by means of an entry in BCD to run grub2win or by an entry to run grld.mbr to load grld and menu.lst to run it, it didn't run.

 

From: https://www.aioboot....n/aio-boot-dvd/

 

Features

AIO Boot DVD is a copy created from the AIO Boot drive. But since it is booted from CD-ROM, there will be some differences. The difference I notice here is from Grub2. In addition, the features are nearly identical.

    Supports UEFI and Legacy BIOS modes. Both modes use Grub2 as the default boot loader.
    Clover, Syslinux and rEFInd are not supported. Grub2 does not support booting Clover and rEFInd from the CD-ROM.
    .....

 

So this means Clover only runs fine from a writable partition.

 
This explains why It didn't run fine from AIO.ima (even if it was made from the USB with single FAT-32 active partition).

 

Conclusion:

 

To make sure CloverLegacy runs fine on a MBR formatted HDD, it has to run from a writable FAT-32 active partition.

 

alacran



#18 Wonko the Sane

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Posted 26 May 2021 - 08:30 AM

Conclusion:

 

To make sure CloverLegacy runs fine on a MBR formatted HDD, it has to run from a writable FAT-32 active partition.

 

alacran

Yes, or no, or maybe.

 

IF Clover can access a grub4dos virtual drive, I cannot see why a (small) FAT32 partition cannot be --mem mapped, the whole point revolves around whether the Clover "trusts" BIOS tables or re-scans hardware.

 

Anyway, apart from the (BTW nice) exercises in style, it has no practical use for Operating Systems (like the Windows 7+ ) that can boot BOTH on BIOS and UEFI, in these cases it is only an added layer of complexity and possible source for errors.

 

With Operating Systems that can only boot from UEFI, it is - on the opposite - extremely useful and needed if the hardware is BIOS only, but again a motherboard that has BIOS only is unlikely to have the "juice" needed to run an OS that is UEFI only, so outside the Mac/Hackintosh realm it remains something that is little more than a (again nice, fun) experiment..

 

If you are still interested, the next experiment could be booting on BIOS only hardware from GPT disk (making use of the UMBR or my underfloppy approach, or some other workaround to allow the BIOS to initially boot from GPT and get to load the Clover).

 

:duff:

Wonko


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#19 alacran

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Posted 26 May 2021 - 12:06 PM

My friend, It seems to me you missunderstood some things, just to make clear it for you:

 

About:

 

IF Clover can access a grub4dos virtual drive, I cannot see why a (small) FAT32 partition cannot be --mem mapped, the whole point revolves around whether the Clover "trusts" BIOS tables or re-scans hardware.

 

On the second test on post No. 5 I tested that approach using an AIO.ima file using map and also map --mem commands and in both ways was able to load/run the grub2 legacy menu of AIO_Boot, boot Clover does not run in any of both cases.

 

 

Then so far I was able to integrate the content of the AIO_Boot USB device into the bootable partition, and sucessfully load AIO_Boot menus, but Clover (legacy) does not run this way.

 

What CloverLegacy does, (at least from AIO_Boot) is load the EFI\Microsoft\Boot\BCD menu (wich was used during Filedisk booting), but during Rambooting Clover was not used:

 

From Post No. 16

 

when booting and the grub2 legacy menu is loaded, selecting option 5 Boot Windows on Hard Disk I arrive to \Boot\BCD menu and selecting from it Grub4dos Menu then the menu.lst is loaded, and next step is select the VHD Ramboot option, and it Rambooted flawlessly.

 

About:

 

Anyway, apart from the (BTW nice) exercises in style, it has no practical use for Operating Systems (like the Windows 7+ ) that can boot BOTH on BIOS and UEFI, in these cases it is only an added layer of complexity and possible source for errors.

 

Here you are wrong including 7x64 on your statement, it does not fully support booting from UEFI since it lacks the video drivers required during first boot stages, going further it can't be installed on UEFI for this reason, but there are some tricks (by the way based on Clover and similar programs, that may work sometimes but not always).

 

Anyway, I also think there is no avantage in boot from a Clover emulated UEFI environment:

 

From Post No. 10

 

In fact once the OS boots it acts the same on a Bios or on a UEFI environment, and for the user there is no advantage in booting it one way or the other.

 

As mentioned on first post of this topic, I started running some test after reading your posts mentioned there, to satisfy my curiosity and make sure if a full Win10 that was previously running on a Bios machine on MBR disk, was capable to boot on same (Bios) machine on Clover emulated UEFI environment or not, with the minimum changes possible, wich is using the USB stick and making active partition FAT-32 and rebuilding boot files/folders to also have EFI folder.

 

And once started, one thing taked me to the next and so on.

 

But I think if a person starts runing some tests or experiments it is necessary to cover all possible options, and share the info, even if it is a not very usefull thing as in this case, if not better don't do it.

 

I have gotten many good ideas and motivation to learn from other people experiments, I remember very long time ago I read a topic where cdob and wimb just by (offline loading and) editing a  single value in the registry made the 7 embeded (or what ever it was called then) USB native bootable, it was not very practicall to me as I was not running that 7 version, but it made me learn how to offline load and edit the registry.  Testing Misty projects made me learn to write WinPE scripts, so then who knows, maybe this topic can give to some reader an idea to make other things, or motivate him/her to learn something else.

 

Anyway if some people, for whatever reason wants info abot this subject, the info will be available here.

 

And by the way I think I found the way to Ramboot VHDs on Clover emulated UEFI environment, but I need to test it first, and that will be my final post on this topic.

 

alacran



#20 Wonko the Sane

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Posted 26 May 2021 - 12:21 PM

Sorry, I misunderstood you, and I am wrong, it was really needed that you made this clear to me, thank you.

 

:duff:

Wonko

 

P.S.: 

Note for self:

avoid posting (polite) suggestions on alacran's threads, as they will be likely ignored, whilst the rest (comments and opinions provided for context) will be nit-picked to death.

Errare humanum est ...



#21 relynx

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Posted 26 May 2021 - 12:22 PM

[SCRIPT_1] This is also a handy script to make a Clover boot device (Link).

 

 

...

 

If you are still interested, the next experiment could be booting on BIOS only hardware from GPT disk (making use of the UMBR or my underfloppy approach, or some other workaround to allow the BIOS to initially boot from GPT and get to load the Clover).

 

:duff:

Wonko

That's what I did in my brief run through.
The Linux script does what you're looking for.
The same tools needed to accomplish the task on Windows should be easyly found.
Or just boot up a Linux VirtualBox and pass the USB stick through and run the provided script.

I'm booting the created GPT stick on my 10-year old and MBR-only ACER 4830T laptop.
Btw, Win10 is still usable on it with an i3-2310M CPU.



#22 Wonko the Sane

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Posted 26 May 2021 - 12:32 PM

@relinx

Thanks :) , but I was not looking for it, I was pointing to a couple ways to have a "normal" GPT disk have a "special" MBR code (and in one solution an added usage of unused sectors for a few needed boot files) bootable on BIOS/MBR (in my perverted mind simpler than your "pre-requisite" of Ubuntu 20.04).

 

BUT IF the Clover does not read the BIOS tables and rescans hardware they both won't probably work as they both rely on loading grub4dos and then make special disk/drive mappings in it)..

 

On the other hand IF this latter happens AND there is a suitable GPT partition, the approach may work. :unsure:

 

I guess we'll never know for sure. :dubbio:

 

:duff:

Wonko



#23 devdevadev

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Posted 26 May 2021 - 01:03 PM

http://reboot.pro/in...=9
http://reboot.pro/to...able-usb-drive/

#24 relynx

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Posted 26 May 2021 - 01:09 PM

... , or some other workaround to allow the BIOS to initially boot from GPT and get to load the Clover).

There is no workaround needed. Clover is all you need.

 

... (in my perverted mind simpler than your "pre-requisite" of Ubuntu 20.04)

 

[FOLDER_1] and [FOLDER_2] are only needed to show case that Clover can boot EFI installs on a MBR-boot-only PC.
As a matter of fact: See the Linux script as an automated way to create the USB Clover bootstick.
You're free to choose the tools to accomplish the task as long as your OS has the right tools in its arsenal.
How one can do it manually is described in the script.

 

... BUT IF the Clover does not read the BIOS tables and rescans hardware they both won't probably work as they both rely on loading grub4dos and then make special disk/drive mappings in it

 

 

Your call for experiment did not mention anything about grub4dos.
Out of interest: What would not work if you're only using Clover as is without grub4dos?
 



#25 Wonko the Sane

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Posted 26 May 2021 - 01:53 PM

Your call for experiment did not mention anything about grub4dos.
Out of interest: What would not work if you're only using Clover as is without grub4dos?
 

Well, both the methods mentioned (my half-@§§ed batches and the UMBR) are meant to load grub4dos, so it was "implied", my bad I didn't make it explicit

 

As always it all revolves about which bootmanager/bootloader you want to be the "primary" one, with grub4dos (and now with the added grub4uefi or whatever it is called) as well as with GRUB2 (though IMHO with some added complexity) once you are in the bootmanager you can chainload *everything* or *nearly everything*, whilst the same cannot be said about other bootmanagers, surely if you want to simply boot a given OS that is supported/works fine with Clover, and in a setup that is compatible, you don' t need anything else.

 

:duff:

Wonko







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