Edit Nvram File

[Martta]

OnMac OS X there is a tool called nvram to get and set EFI properties. As I am now deploying GNU/Linux on Apple hardware, I'd like to have a similar tool that is able to talk to Apple's EFI implementation.

With BIOS, the motherboard stores the order of physical devices to boot from in non-volatile memory (NVRAM) so it survives a reboot. This ensures when you turn the machine on the motherboard still boots devices in the order you (or the factory) configured it to. The BIOS will then try executing the MBR in the first logical block address (LBA) of each device until one of them works. If you manually select a device to boot during startup it will do as you ask and attempt booting from the first LBA of that device instead.

Assuming a disk is formatted with GPT, when the motherboard uses UEFI booting the MBR doesn't need to contain a bootloader (or anything for that matter). Instead, the disk contains an EFI System Partition (ESP) which is essentially a FAT-formatted partition containing bootloader code stored in files. The FAT filesystem may also contain other files needed by the bootloader (e.g. logos and backgrounds used by a splash screen during the boot process).

For UEFI booting on a UEFI motherboard it is assumed the disk is part of the system so when you grub-install, part of that installation process should be placing an entry into the motherboard's NVRAM containing the path of the bootloader within the ESP (see section 3.5.1 Boot via the Simple File Protocol of the UEFI spec). This entry can then be set to the default, or just presented as an option. For more information on EFI Boot Loaders I strongly advise reading Rod Smith's Managing EFI Boot Loaders for Linux.

For a device which is not normally attached to a motherboard (i.e. USB hard disk) it does not make sense to store this entry in the motherboard's NVRAM as the device might not be there during most boots. I believe the --no-nvram option tells the grub-installer not to modify the motherboard's NVRAM for this purpose.

Furthermore, if a motherboard is instructed to boot from a removable device for which it has no boot entry in its NVRAM, UEFI defines a default path for it to try booting from (see section 3.5.1.1 Removable Media Boot Behavior of the UEFI spec). The path, relative to the root of the ESP is \EFI\BOOT\BOOTarchitecture.EFI with the following architectures.

I believe the --removable option tells the grub-installer to use this path, rather than its preferred path is probably necessary if not modifying the motherboard's NVRAM otherwise one would need to manually specify the bootloader after manually selecting the removable device.

I realise none of this explains why your motherboard won't allow GRUB to modify its entries. But hopefully that explains why that switch helps. The error message you provided suggests all of the motherboard's boot entries have been populated and, quite reasonably, it isn't appropriate for grub-install to decide which of your boot entries to overwrite. You could try using efibootmgr to display your boot entries and delete some that you don't need. Rod Smith's answer to this question should show you how.

NVRAM is non-volatile RAM that is used in EFI to store variables that need to persist between boots. Many of these NVRAM variables are architecturally defined, and setting invalid options to NVRAM could cause a machine to not be able to boot.

I'm building the second node as per the install instructions but am getting a system id mismatch error after setting the env variables SYS_SERIAL_NUM and bootarg.nvram.sysid. Any suggestions? This is the 8.2.1RC1 version of the simulator in cluster-ontap mode.

I didn't see a cf vmdk, but I did replace the DataONTAP-var.vmdk and DataONTAP-sim.vmdk files with original ones from the tgz package. I had also found and edited a file called env within the cfcard\env directory of the virtual machine folder. Replacing just the -var.vmdk didn't work, but after editing the env file with the updated serial info I used in the instructions and replacing the -sim.vmdk file, I got past the error that prevented the simulator from booting. I don't know if editing the env file directly had anything to do with this, but this file still contained the original SYS_SERIAL_NUM and bootarg.nvram.sysid.

Glad you got it working. The env file is a remnant of the build process, and not actually used by the simulator. A copy of it lives on the boot device, DataONTAP.vmdk - historically a compactflash card, and represents the initial boot environment for the simulator. If you are going to make changes, such as modifying the serial, switching modes or adjusting the simdisk inventory, its best to catch the very first boot. During the first boot, the nvram is discarded, /var is populated, and /sim is populated with simdisks. If you miss the first window and have problems its easier to start over with clean files than it is to reset and re-arm those initialization processes.

if you want to modify nvram.bin you can modify this in your rooted devicethis is folder in /data/nvramafter modify you can backup by mtk driod tools: -and-restore-imei-nvrammtk droid gives to you a nvram.bin file!

I cannot change any of NVRAM variables using SSH which confuses me. If I have all ports in same vlan and want to separate them in two, let's say to make dmz or to have one port in vlan with wifi, and all others in separate vlan I do trivial nvram commands which can be found all around Internet and after that make: nvram commit. Or I want to disable DHCP on LAN or WAN or anything like that....

Next is there any chance to list just one nvram parameter, not listing all the configuration? If I do:

nvram show - I have all configuration listed

Now, I would like to see something like lan_ipaddr or lan_dhcp_enabled or .... I don't want to go through all configuration I want listed just this parameter.... it would be nice to have it like

nvram show lan_dhcp_enabled

but, when I print something like this it has no errors and list hole configuration again.... which is stupid, or it's me..... HELP ?

We wanted to get away from Windows and make our older Acer Aspire run better, so we bought a new hard drive and removed the old one with Windows to have as clean an install of Zorin as possible.

Unfortunately all we get after install is " Error: NVram is locked (Zorin not found in efibootmgr). Please report this message to boot....@gmail.com".

After two hours of searching for a solution no one has one. We tried resetting the bios defaults and ensured there is no security password and we still get the same error.

I'm glad we didn't pay for Zorin yet or we would have lost that money as well.

And, last one promise - try the Boot Repair utility in your USB installer through the provided live session (desktop). Select the Recommended Repair option and try to boot again once it completes.. if that doesn't work, provide any and all details including screenshots (if you can) to the reply

That's telling me your boot style is MBR, older for sure. No worries, you just need to make an MBR type installer with either Unetbootin, or Rufus by changing the "Target System" format from 'UEFI' to 'MBR' and installing Zorin again. . Kind of a pain, yeah - but older stuff needs a slightly different installation method.

I already read that and it's not helpful, nor applicable. I also did a considerable amount of research before trying Zorin. That was one of the reasons I chose to reduce complications by putting in a new drive and having a clean standalone version of Zorin.

Also from your log - if you're writing with Unetbootin it's not going to work after all. You'll need to use Rufus or Etcher to get an EFI bootable. Also you could just extract the .ISO file to the root of an NTFS formatted USB. But, do have that from the log so actually - I was wrong! But, won't work unless you write in an EFI bootable.. (edit) or, enable CSM / Legacy settings in BIOS and proceed with your MBR installed Zorin OS - it just sounds like a mismatch of BIOS and boot format to me. Pretty common though, nothing to take to heart.

I finally got BalenEtcher to work and made a new install drive with a new download of ZOS and I get the same error. No boot drive detected.

There are no CSM / Legacy settings and no option in Etcher to change the format.

They sell Zorin OS as a savior of older computers yet clearly haven't addressed the requirements for older computers to make it work, and won't help unless we pay first. I'm not paying for software only to find out I still can't use it.

I know, this can be very frustrating - but, sounds like a BIOS setting either enabled or disabled preventing boot. Or, possibly a different device selected for the first boot device other than the HDD/SSD which won't have a bootloader and throw the 'no boot device' error.

System configuration variables are stored in system NVRAM. These OpenBootvariables determine the startup machine configuration and related communicationcharacteristics. If you modify the values of the configuration variables, anychanges you make remain in effect even after a power cycle. Configurationvariables should be adjusted cautiously, however, because incorrect settings canprevent a system from booting.

Setting the security modeand password can be dangerous: If you forget the password, the system is unableto boot. It is nearly impossible to break in without sending the CPU to Sun tohave the PROM reset. OpenBoot security is discussed more in the section"OpenBootSecurity," later in this chapter.

The security mode password you assign must be between zero and eightcharacters. Any characters after the eighth are ignored. You do not have toreset the system after you set a password; the security feature takes effect assoon as you type the command.

On non-USB style keyboards, notUSB keyboards, if you change an NVRAM setting on a SPARC system and the systemno longer starts up, you can reset the NVRAM variables to their default settingsby holding down Stop+N while the machine is powering up. When you issue theStop+N key sequence, you hold down Stop+N immediately after turning on the powerto the SPARC system; you then keep these keys pressed for a few seconds or untilyou see the banner (if the display is available).

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