Wannabe Hacker Posted January 12, 2022 Share Posted January 12, 2022 I have a NUC6CAYH which has an Intel Celeron Processor J3455. I was creating a dual boot Windows/Ubuntu installation when I accidentally inserted and selected from the boot menu my OpenCore USB for a hackintosh I had created on a Gigabyte Z490 Vision D board.  I was NOT trying to install OpenCore on my NUC. Ever since making that selection, every time I insert a bootable UEFI USB, my BIOS brings up OpenCore as the selection and I cannot boot into the USB. For example, when I insert my Ubuntu Live USB, the only boot menu item reads OpenCore bootloader. If I select it, it will not boot into Ubuntu Live. I have also tried it with my Windows installation USB and the exact same thing happens.  This board does have a legacy boot option which seems unaffected, but I cannot boot via UEFI USB. Every time I insert a bootable UEFI USB, all I see is OpenCore boot loader in my boot selection menu. I have tried resetting my BIOS by disconnecting the battery, clearing via the jumper as well flashing a new updated BIOS all to no avail.  OpenCore appears to be intimately integrated into my BIOS. I don't know what else to do.  My NUC is essentially bricked and I cannot boot into any operating systems other than via legacy mode which makes it useless for my purpose. Does anyone have any ideas?  Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/ Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) OpenCore is not intimately integrated into the BIOS, it sounds as if it has saved its boot entry into your system's NVRAM (which it is supposed to). A fix could be as simple as going into your system BIOS setup boot menu management screens and deleting the OpenCore boot menu entry. Edited January 12, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774967 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 1 hour ago, Bmju said: OpenCore is not intimately integrated into the BIOS, it sounds as if it has saved its boot entry into your system's NVRAM (which it is supposed to). A fix could be as simple as going into your system BIOS setup boot menu management screens and deleting the OpenCore boot menu entry.  Appreciate the info. Unfortunately I don't think the fix is as simple as you describe. To start, this BIOS does not have to ability to "delete the OpenCore boot entry".  Boot entries can be reassigned priority but they cannot be deleted.  The bigger problem is that the OpenCore boot menu entry is the ONLY boot option I am given regardless of what operating system installation USB I insert.  If I insert my Ubuntu Live USB I am not even given a UEFI Ubuntu boot option. The only option is "OpenCore boot loader".  Selecting it does not result in my Ubuntu USB booting. The system just freezes.  Thus, I am unable to boot into any operating system.  Every UEFI USB I insert is associated with OpenCore and OpenCore ONLY. I have tried Ubuntu, Windows, and pfSense installation USB's that I know work and boot on my other systems with the same result.   As for resetting the NVRAM, I would have thought that the BIOS reset maneuvers that I tried (ie removing the battery, resetting the CMOS jumper) would have cleared the NVRAM. Every other setting does get cleared including the date and clock but this OpenCore association remains.   I have researched and cannot identify any other way to clear the bios. Is there anyway I can construct an OpenCore USB for this board and reset the NVRAM?  The little I have researched suggests that this processor is not compatible with a Hackintosh because the graphics are not supported.  Maybe the developers of OpenCore can provide a tool or script that I can use to reset the system? Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774977 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) It seems very strange that there is no way to delete a boot entry. I don't think I've ever seen a BIOS without that. Can you maybe send a screenshot of the BIOS boot entry screen? Â (There are other ways to delete a boot entry as well, like adding UEFI Shell as an entry to OpenCore, then using the commands in that to delete the entry you don't want.) Edited January 12, 2022 by Bmju Update Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774980 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 32 minutes ago, Bmju said: It seems very strange that there is no way to delete a boot entry. I don't think I've ever seen a BIOS without that. Can you maybe send a screenshot of the BIOS boot entry screen?  (There are other ways to delete a boot entry as well, like adding UEFI Shell as an entry to OpenCore, then using the commands in that to delete the entry you don't want.) Here are pics of when I select the boot menu option as well as what it looks like when I enter my BIOS.  The USB that has been inserted in this case happens to be a Clonezilla Live USB but it doesn't seem to make any difference what UEFI USB I inert,  this is what I see. 23 minutes ago, Hervé said: OpenCore bears no relation to the CPU compatibility or incompatibility with macOS. I'd just create an OpenCore bootable USB key and, at the Picker, Reset NVRAM. Then quickly remove the USB key as your NUC resets.  I tried using the OpenCore USB that got me into this trouble but I can't get to the picker. It just freezes. Do I need a special configuration for this board and processor to get to the picker? Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774985 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) What is in the Boot Configuration tab? (Or if you try right-clicking on a boot entry - does that exist?) Edited January 12, 2022 by Bmju Update Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774987 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) This seems not specific to OpenCore - doesn't mean it cannot be fixed - but I think this sounds like the same problem, not involving OpenCore: https://community.intel.com/t5/Intel-NUCs/NUC-BIOS-keeping-old-boot-device-data/td-p/558960 Â Can you boot anything? i.e. when you don't have a USB in there, is there any OS on there? (e.g. Linux, where you could install efibootmgr?) Edited January 12, 2022 by Bmju Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774988 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) More of the same (not problem with OC, but with NUC): https://community.intel.com/t5/Intel-NUCs/Unable-to-add-more-than-one-custom-entry-to-bios-boot-menu/td-p/1187620 Â I think Linux `efibootmgr` or UEFI Shell `bcfg` are your best bets. I am sure you do need to remove the OpenCore boot entry, but it is a unique problem of your system that this entry is the only one showing. Â (Btw NVRAM is non-volatile, so it _should_ survive removal of power.) Edited January 12, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774989 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 32 minutes ago, Bmju said: What is in the Boot Configuration tab? (Or if you try right-clicking on a boot entry - does that exist?) Â Here is the boot config tab. Right clicking the boot entry only gives me the option of adding to favorites. No option to delete. Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774990 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 38 minutes ago, Bmju said: What is in the Boot Configuration tab? (Or if you try right-clicking on a boot entry - does that exist?) I sent the wrong pic showing right-clicking the boot entry. This is the right one 26 minutes ago, Bmju said: This seems not specific to OpenCore - doesn't mean it cannot be fixed - but I think this sounds like the same problem, not involving OpenCore: https://community.intel.com/t5/Intel-NUCs/NUC-BIOS-keeping-old-boot-device-data/td-p/558960  Can you boot anything? i.e. when you don't have a USB in there, is there any OS on there? (e.g. Linux, where you could install efibootmgr?) Unfortunately, I don't have an SSD with a functioning operating system.  I was in the middle of trying to repair a dual boot configuration (Windows/Ubuntu) when this disaster occurred.  So, I don't have a functioning operating system other than my Live USB's, none of which I can boot. Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774991 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 45 minutes ago, Bmju said: What is in the Boot Configuration tab? (Or if you try right-clicking on a boot entry - does that exist?) As I was looking at that configuration pic, I noticed the option to boot into a "Internal UEFI shell". Selecting that gives the following. Â This looks like it could prove useful but I don't my way around this type of shell Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774992 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) You need UEFI Shell. This person resolved the issue using the UEFI Shell of OpenCore: https://community.intel.com/t5/Intel-NUCs/Unable-to-add-more-than-one-custom-entry-to-bios-boot-menu/td-p/1187620 Â I think this should work - take the OpenCore USB, then rename /EFI/OC/OpenCore.efi to /EFI/OC/OpenCore.bak, then copy /EFI/OC/Tools/OpenShell.efi to /EFI/OC/OpenCore.efi. Then insert and boot. The aim of this is to get OpenShell to boot, using the one boot entry you have! (Or you can just make a new USB, where the only file is OpenShell.efi, but renamed and placed at the path /EFI/OC/OpenCore.efi .) Â Once you have booted from that and started OpenShell, use these instructions to use `bcfg` list and remove boot entries (and remove the one for OpenCore): https://superuser.com/a/931016/439040 Â Update: Yes, try `bcfg` command in the built-in shell - if it has it, use that. If it doesn't, you can try what I said to start OpenShell (which is basically the same thing, but with more commands included). Edited January 12, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774993 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 These are the available commands for UEFI shell. Â Feel free to jump in with any ideas. Â I'll try playing around as best I can. Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774994 Share on other sites More sharing options...
Avery B Posted January 12, 2022 Share Posted January 12, 2022 (edited) You'll specifically want the "bcfg" command. I don't remember how to use it, it's a little confusing, but it'll allow you to play with boot order and add/remove entries. I believe you can list entries using "bcfg boot list". All the commands should be under "bcfg boot". Edited January 12, 2022 by 1Revenger1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774995 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 2 minutes ago, 1Revenger1 said: You'll specifically want the "bcfg" command. I don't remember how to use it, it's a little confusing, but it'll allow you to play with boot order and add/remove entries. I believe you can list entries using "bcfg boot list". All the commands should be under "bcfg boot". I tried but the internal UEFI shell does not recognize the "bcfg" command. Any options from the list I sent that I should try? Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774996 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) These are the commands:  bcfg boot dump  If OpenCore is Boot0003  bcfg rm 3 reset  Your UEFI shell does not have bcfg, so use my instructions above to start OpenShell.efi, which is the same, but does have it.  Or you can use UEFI Shell to launch OpenShell.efi, instead. To do that, it's basically  FS2: cd \EFI\OC\Tools OpenShell  But it might not be FS2:, but another drive.   Edited January 12, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774997 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 17 minutes ago, Bmju said: You need UEFI Shell. This person resolved the issue using the UEFI Shell of OpenCore: https://community.intel.com/t5/Intel-NUCs/Unable-to-add-more-than-one-custom-entry-to-bios-boot-menu/td-p/1187620 Â I think this should work - take the OpenCore USB, then rename /EFI/OC/OpenCore.efi to /EFI/OC/OpenCore.bak, then copy /EFI/OC/Tools/OpenShell.efi to /EFI/OC/OpenCore.efi. Then insert and boot. The aim of this is to get OpenShell to boot, using the one boot entry you have! (Or you can just make a new USB, where the only file is OpenShell.efi, but renamed and placed at the path /EFI/OC/OpenCore.efi .) Â Once you have booted from that and started OpenShell, use these instructions to use `bcfg` list and remove boot entries (and remove the one for OpenCore): https://superuser.com/a/931016/439040 Â Update: Yes, try `bcfg` command in the built-in shell - if it has it, use that. If it doesn't, you can try what I said to start OpenShell (which is basically the same thing, but with more commands included). Unfortunately, the internal UEFI doesn't recognize the 'bcfg' command. I posted a pic above of the available commands. Â Appreciate all the links. Â Will probably take some time for me to digest what you sent me. Â I'm not a total noob but I'm certainly not highly proficient at stuff like this. Â Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2774999 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 We're posting at the same time! Insert OpenCore USB. Boot, but enter builtin UEFI Shell. Use that to start OpenShell.efi (my previous message). Then use _that_ to run bcfg (my previous message). Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775000 Share on other sites More sharing options...
Wannabe Hacker Posted January 12, 2022 Author Share Posted January 12, 2022 (edited) 7 minutes ago, Bmju said: We're posting at the same time! Insert OpenCore USB. Boot, but enter builtin UEFI Shell. Use that to start OpenShell.efi (my previous message). Then use _that_ to run bcfg (my previous message). Nothing happens when I insert my OpenCore USB. I can't get to any OpenCore menu or shell. I've tried using 2 different OpenCore UBS's. One was created for a Gigabyte Z490 board and the other was for an Asus Z87. Â Neither one will boot to anything. I confirmed that they both work when I try in my other systems. Edited January 12, 2022 by MacGeoDoc Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775002 Share on other sites More sharing options...
Bmju Posted January 12, 2022 Share Posted January 12, 2022 (edited) Don't try to start OpenCore.  Put the OpenCore USB in [with power off], then [power up and] start the shell that you found.  Now you need to figure out which drive the OpenCore USB is on, but let's say it's FS2:, then do:  FS2: cd \EFI\OC\Tools OpenShell.efi  That will start a second shell, which has bcfg, which you need!     Edited January 12, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775003 Share on other sites More sharing options...
Wannabe Hacker Posted January 13, 2022 Author Share Posted January 13, 2022 17 minutes ago, Bmju said: Don't try to start OpenCore.  Put the OpenCore USB in [with power off], then [power up and] start the shell that you found.  Now you need to figure out which drive the OpenCore USB is on, but let's say it's FS2:, then do:  FS2: cd \EFI\OC\Tools OpenShell.efi  That will start a second shell, which has bcfg, which you need!     Thank you for that clarification. Yes, that worked.  I'm in OpenShell.  Will keep you posted 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775004 Share on other sites More sharing options...
Wannabe Hacker Posted January 13, 2022 Author Share Posted January 13, 2022 (edited) 1 hour ago, Bmju said: These are the commands:  bcfg boot dump  If OpenCore is Boot0003  bcfg rm 3 reset    Success!!! It worked!!  I'm so happy 😀.  I am so grateful for all of the help.  In case anyone happens to find/need this thread I would like to make a couple of corrections to the instructions you gave me above.  The command to remove the entry is actually "bcfg boot rm" not "bcfg rm".  Also, the value to remove is not contained within "Boot000X" but rather following  "Option:".  See my pic below.  Regardless, I could not have done it without your valuable assistance. Now, back to my original troubles....😉   Edited January 13, 2022 by MacGeoDoc 1 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775006 Share on other sites More sharing options...
miliuco Posted January 13, 2022 Share Posted January 13, 2022 @Bmju great help! I liked all the history. Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775011 Share on other sites More sharing options...
Bmju Posted January 13, 2022 Share Posted January 13, 2022 (edited) We have added info about this problem and workarounds to the OpenCore documentation:Â https://github.com/acidanthera/OpenCorePkg/commit/d4ffdae05f2d5f2cceb160b1d0b60cc22b82248b Edited January 13, 2022 by Bmju 1 Link to comment https://www.insanelymac.com/forum/topic/350367-problem-with-opencore-corruption-of-nuc6cayh-bios/#findComment-2775033 Share on other sites More sharing options...
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