This tag is used for questions related to use of the gnu-efi toolkit to build UEFI applications, as opposed to generic questions around UEFI.
gnu-efi is a set of libraries and scripts used to build UEFI applications in a Linux environment.
Questions tagged [gnu-efi]
50 questions
0
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1 answer
Writing my first EFI application with gnu-efi
I got an Alexa device and I’m using an esp8266 to get request from the echo dot.
I can wake on lan my Pc but it’s not enough. I have windows and Linux on my Pc so I thought “I need some code to run before boot so I can communicate with my esp8266 to…
Raffaele Bertani
- 29
- 7
0
votes
1 answer
Send TCP or UDP packets from efi application
I want to develop an application to be automatically executed from startup.nsh in EFI shell. This application should send raw bytes to an ip address and receive some back. I looked everywhere for explanation and example for the implementation of…
Raffaele Bertani
- 29
- 7
0
votes
1 answer
qemu hangs after booting a GNU-EFI os
I was trying to write a "hello world" x86_64 OS with GNU-EFI according to an article:https://wiki.osdev.org/GNU-EFI, but I ran into some problem.
When I boot the img using following command
sudo qemu-system-x86_64 -drive…
xubury
- 84
- 6
0
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0 answers
UEFI - How to improve graphics's performance?
I am trying to draw a cursor with GOP. Cursor drawing happens in while loop.
My file where GOP located: https://drive.google.com/file/d/1neifcwzow4WLGId7LRCzEFx5n43narDi/view?usp=sharing
/*...OTHER CODE...*/
RunGraphics(...); //CLEAR…
Gomi Odabaşıoğlu
- 156
- 1
- 14
0
votes
2 answers
Is that possible to use standard libc features in GNU-EFI with Visual Studio?
I am using gnu-efi as Visual Studio 2019 project. My UEFI program works as expected on real hardware. Next step, I need C features like "pow(...);". Naturally, when working with efi all of these features are disabled. When I directly include…
Gomi Odabaşıoğlu
- 156
- 1
- 14
0
votes
1 answer
EFI Memory Map returns 0 sections of EFIConventionalMemory
As stated in the title, getting the EFI Memory Map in a UEFI bootloader is yielding no sections of EFIConventionalMemory. If I'm not mistaken, this should be the majority of the memory?
It is returning this on both QEMU and on real hardware. Setting…
Poncho
- 11
- 3
0
votes
3 answers
How can I get a protocol working under GNU-EFI?
I use GNU-EFI to develop UEFI apps. I have some trouble getting a protocol (EFI_SHELL_PROTOCOL) working under GNU-EFI. My compiler says that it is undefined. Should I include something? I already included efi.h and efilib.h. Do I need more?
Code…
Moldytzu
- 25
- 9
0
votes
1 answer
UEFI c++: when using Print, wchar_t convertion error happens
I want to try to make a little (U)EFI bootloader in c++, but, when I try to compile my code (with g++) gives this error:
boot.cpp: In function ‘EFI_STATUS efi_main(EFI_HANDLE, EFI_SYSTEM_TABLE*)’:
boot.cpp:9:9: error: invalid conversion from ‘const…
FoxWare
- 14
- 2
0
votes
2 answers
Wait for key press GNU EFI
How do I wait for a key in GNU EFI?
I intend it to wait for a single key, then continue execution.
My code:
#include
#include
#include
EFI_STATUS efi_main (EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) {
…
randomuser5215
- 508
- 1
- 9
- 26
0
votes
1 answer
Where is the actual code for UEFI boot services in EDK 2, or where the System table is being populated in EDK 2 source
I am working on a Virtualization layer, in particular Virtualizing UEFI Boot Services, so that these services can be used even after ExitBootService() is called and control is passed on to GPOS kernel, be it Windows/Linux. I cannot locate actual…
U. Saleem
- 1
- 1
0
votes
1 answer
Redirect UEFI Shell I/O
I´d like to redirect the UEFI Shell stdin/stdout to work from a remote PC.
I have/see two options:
1) Via a UART/COM interface:
Is there any simple solution to get this run inside the shell? (I don´t want to enter the 'BIOS' settings but start…
El-Coder-SB
- 65
- 1
- 3
- 15
0
votes
1 answer
UEFI - malloc call does not return
i will try to keep this as short as possible.
I created an UEFI application which uses just a simple malloc but it never returns from the call:
main.c:
#include
#include
#include
EFI_STATUS
EFIAPI
efi_main (EFI_HANDLE…
Oachkatzl
- 307
- 1
- 11
0
votes
0 answers
How to wait for network packet with GNU-EFI simple networking
I'm trying to use the EFI simple network protocol:
http://wiki.phoenix.com/wiki/index.php/EFI_SIMPLE_NETWORK_PROTOCOL
to wait for an incoming ethernet packet. However, using QEMU, the WaitForPacket event never triggers even with incoming packets,…
0
votes
1 answer
UEFI secure boot issues with hello efi
I have created one efi and signed with pesign using the docs -
UEFI secure boot…
ninja.stop
- 410
- 1
- 10
- 24
0
votes
1 answer
UEFI read variable with RT->GetVariable
Iam new in coding. So i try to keep it much simple as possible. My goal is to read uefi variables like vendor/serial and print it back. My Code will not work like it should. Iam using gnu-efi.
include "efi.h"
include "efilib.h"
CHAR16* …
KingBonecrusher
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