New answers tagged grub2
Well, the OS is what installs the bootloader in the first place, so clearly it has some control over it. UEFI firmwares have an integrated boot manager, which stores the menu choices and other parameters as EFI variables such as Boot0001, BootOrder, BootNext. They're stored in the same NVRAM as other firmware settings – in fact, many firmware settings are ...
It's possible because the OS does have control over the bootloader. You have the bootloader confused with the BIOS, which is entirely different. When your computer boots up, the following happens: It does the POST checks Control is passed to the BIOS to choose which device to boot from. This is what the OS has no control over. Once it's found a device to ...
First, a useful tool for investigating almost any boot problem involving Linux is the Boot Info Script. This tool spits out a file called RESULTS.txt that includes most of the information necessary to troubleshoot most boot problems involving Linux. Please run that script and examine the results. If you can't figure it out yourself from there, you'll ...
No, you can't do that conversion with diskpart and retain your data. You can do the conversion with gdisk (included with Ubuntu) and retain your on-partition data, but neither OS will be bootable after you complete the conversion. You can restore both OSes to bootability, but it's a bit of a hassle. Why do you want to do this conversion? The most compelling ...
Yup, that weird entry in grubenv was the issue. I renamed the file and rebooted and I have gloriously full grub2 functionality again. Thanks for rubber-ducking, SuperUsers.
Try boot-repair-- it fixes problems just like yours. http://www.howtogeek.com/114884/how-to-repair-grub2-when-ubuntu-wont-boot/ HTH
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