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Questions tagged [uefi]

The Unified Extensible Firmware Interface (UEFI) is a specification that defines a software interface between an operating system and platform firmware. UEFI is meant to replace the Basic Input/Output System (BIOS) firmware interface.

The Unified Extensible Firmware Interface (UEFI) is a specification that defines a software interface between an operating system and platform firmware. UEFI is meant to replace the Basic Input/Output System (BIOS) firmware interface.

For more information see:

408 questions
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Writing an OS with UEFI

I haven't been coding much lately due to school but I've decided I want to start working on OS development again. Recently however I've heard stuff about EFI as the replacement to BIOS. I want to develop an OS for a platform that uses EFI rather…
Hudson Worden
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Use of redefining void pointer to pointer to an anonymous structure?

I was working with UEFI driver-related code, and I came across this: /* EFI headers define EFI_HANDLE as a void pointer, which renders type * checking somewhat useless. Work around this bizarre sabotage * attempt by redefining EFI_HANDLE as a…
achoora
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How does UEFI work?

I was studying about bootloaders when exactly came upon the term UEFI. I can understand some things about UEFI. But still, In what mode(Real,Protected,Long) does a system with UEFI start? If normal boot loaders cant work with UEFI, Then what is the…
prog481
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What sort of things are UEFI "applications" actually used for?

I'm interested in PC firmware programming, and am just studying the UEFI spec. To my surprise, it seems like a spec for an entire OS which is embedded in firmware. You can even write UEFI "applications", which run directly using the UEFI boot…
Alex D
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Install VMware : Could not open /dev/vmmon: No such file or directory. Please make sure that the kernel module `vmmon' is loaded

I downloaded the VMware S/W from official website and installed the same. When I try to run any virtual machine it shows error Could not open /dev/vmmon: No such file or directory. Please make sure that the kernel module `vmmon' is loaded and says…
Manthan
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Debug GRUB2 EFI image running on QEMU

What I want to achieve I want to customize a GRUB EFI image, and debug it while running on QEMU. So I'm trying to debug a vanilla GRUB image before customizing it. What I have done so far I downloaded GRUB2 from http://git.savannah.gnu.org and…
lseki
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Run a UEFI shell command from inside UEFI application

I'm new to UEFI application development. My requirement is that, I need to run an UEFI shell command from my UEFI application (app.efi) source code. Need guidance on how I can do this. Example, cp command in UEFI shell is used to copy a file from…
Keshava GN
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Can I write on my local filesystem using EFI

I am working on this project to write files to local filesystem as soon as the OS starts through an EFI application. I need to know if it is possible. And if yes then kindly guide me a little. Thanks
Asak
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How does LinuxBoot differs from Coreboot in the firmware phase?

I am literally confused about the use case of using LinuxBoot as the payload for Coreboot. I learned that LinuxBoot can completely replace the UEFI's DXE and BDS phases, and then can load the bootloader (say GRUB) or even the Linux kernel…
Insane Coder
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UEFI runtime service next to OS

I had the idea of running a small service next to the OS but I'm not sure if it is possible. I tried to figure it out by reading some docs but didn't get far, so here comes my question. I read about the UEFI runtime services. Would it be possible to…
maufl
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Can a UEFI machine use BIOS interrupts?

When the kernel been loaded into the memory, can it still can use BIOS interrupts? Such as mov AX,0E820h int 15h or something.
KME
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The realisticity of writing a full operating system as an UEFI application

Technically UEFI provides a lot of functionality which is part of the groundwork of an operating system, such as a file system. In a way, it is a shame that everything gets discarded and reimplemented by the operating system in the process of…
Thomas F.
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Modifying the ia32 feature control register on Asus Z170 board with buggy BIOS

I'm in the unlucky situation that I need to use a CPU feature that the BIOS hasn't enabled in the ia32 feature control MSR register. The BIOS does set the lock bit so I can't set the bit myself. The BIOS (Asus UEFI BIOS) has no option to change the…
Morty
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Create a Thread in UEFI

Is there a way to have a threaded application running on UEFI? I've only found a few mentions of threading in the UEFI specifications, but they didn't really answer my question.
Jeroen
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Running an EFI application automatically on boot

I can build and manually execute an EFI application in a UEFI environment. But, I'd like to have my application executed automatically at boot time. Is there a way to tell the bootloader to do this or do I need to turn my application in to a driver…
PaulH
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