fmdefrancesco at gmail.com
Thu Sep 23 03:27:10 EDT 2021
On Thu, 23 Sep 2021, 09:22 FMDF, <fmdefrancesco at gmail.com> wrote:
> On Thu, 23 Sep 2021, 09:11 FMDF, <fmdefrancesco at gmail.com> wrote:
>> On Wed, 22 Sep 2021, 08:22 Ruben Safir, <ruben at mrbrklyn.com> wrote:
>>> What is this for?
>>> efivarfs on /sys/firmware/efi/efivars type efivarfs
>>> why would the OS need to know anything about the UEFI
>>> boot loader once it is up and running?
>> I think you are still making confusion: UEFI bootloaders and UEFI are two
>> different entities.
>> UEFI bootloaders (like Grub2) serve the purpose to locate, pass kernel
>> options and platform information to the kernel that themselves are going
>> to boot.
>> Instead the UEFI is an interface between the running OS and the platform
>> UEFI defines two types of services: boot services and runtime services.
>> After booting is done, via UEFI boot services and eventually UEFI
>> bootloaders, the OS does not need anymore the bootloader and the UEFI boot
>> Instead the OS needs UEFI runtime services to talk to the platform
>> firmware. For example, if OS cannot talk to the platform via UEFI, it
>> cannot even shutdown the system (obviously there is much more than simply
>> shutting down). How can an OS know that you've attached a plug and play
>> device if it cannot talk to the platform firmware?
> For sake of completeness and for better understanding that OS need UEFI,
> but not necessarily EFI bootloaders, please read the following document:
> Linux can boot without bootloaders, but it still needs to use UEFI at
While at this, please read also:
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