All Questions
36 questions
0
votes
1
answer
126
views
Is EFI Simple Filesystem protocol always available in UEFI?
In my UEFI Application, I am using the EFI Simple Filesystem protocol to read and create files in the ESP partition.
My question is, is this protocol always available? Meaning can I assume this ...
- 1,046
1
vote
0
answers
85
views
What is the most stable approach for communication between UEFI Runtime Driver and Windows Kernel Driver?
In my UEFI runtime driver, I want to set some flags (UINT) based on some conditions, and then I want to read these in my windows kernel mode driver.
I cannot use the gRT->SetVariable, because the ...
- 1,046
0
votes
0
answers
51
views
Setting Endorsement Primary Seed fails
I am trying to set the EPS in an EDK2 UEFI Application. I always get "Device Error".
int main(int ArgC, char *ArgV[])
{
TPMS_AUTH_COMMAND AuthSession;
AuthSession.sessionHandle = ...
- 11
0
votes
1
answer
54
views
How to tell what kind of event a SCI represents?
I am trying to understand the ACPI event programming model.
According to the ACPI 6.5 spec, SCI (System Control Interrupt) will be raised for two kinds of events: fixed event and general-purpose event....
- 64k
1
vote
0
answers
69
views
How to use .asm in EDK2?
I am trying to use assembly in EDK2. I build an X64 driver so I can't use inline assembly but I always get an error while trying to compile.
I am using a HeciTool.asm that only returns a 0:
section ....
- 11
0
votes
1
answer
177
views
Build failure EDK2
I get:
d:\edk2\SetVariablePkg\SetVariablePkg.dsc(...): error 4000: Instance of library class [OpensslLib] is not found
in [d:\edk2\CryptoPkg\Library\BaseCryptLib\BaseCryptLib.inf] [X64]
...
- 11
2
votes
1
answer
306
views
Can I enable Secure Boot from within an EDKII EFI application?
I want to write the keys (PK, KEK, DB) to enable secure boot, and then enable Secure Boot from within an EFI application.
I can successfully read those variables, and I can also write to the PK, KEK, ...
- 23
0
votes
0
answers
73
views
Run EFI application EDK2
How would I make my UEFI application made with EDK2 execute another .efi in a certain folder path? Let's say my .efi is in fs1:\test1\ and the .efi it should execute is in fs1:\test2?
- 11
0
votes
1
answer
160
views
UEFI application doesn't read user input
I was trying to make a simple application using EDK2 that reads the user input and prints it out, but it doesn't work.
That's my source:
#include "UserInput.h"
EFI_STATUS EFIAPI UefiMain(IN ...
- 11
0
votes
0
answers
169
views
UEFI driver doesn't show "Hello World" in EFI Shell on boot
I made this UEFI driver with EDK2. It prints "Hello, World!" and pauses the Shell for 60 seconds. When I load the driver in EFI Shell manually it works perfectly. I then proceeded to pack ...
- 11
0
votes
0
answers
109
views
Graphics stop working after calling ExitBootServices()
I'm trying to write a printf function to use after exiting uefi boot services, and of course to do it i have to access the frame buffer. Now.. as you can see from the code below, i save the gop frame ...
- 23
1
vote
1
answer
334
views
Does a protocol continue to be in memory and usable by other drivers even after the driver that installed it is unloaded?
If we have a driver that installs a protocol in EDK2/UEFI and then that driver is unloaded, does the protocol continue to exist and be usable by other drivers and services?
Same question for UEFI ...
- 23
3
votes
1
answer
146
views
Most hardware is controlled at the driver level through memory mapped handles. How is RAM controlled? Is there a spec for it?
I'm just getting into the massive topic of learning UEFI driver development and from what I understand so far, hardware peripherals are controlled using specific addresses mapped to memory. Well, the ...
- 827
0
votes
0
answers
348
views
How to programmatically read ThunderBolt firmware from UEFI
ThunderBolt firmware is stored in its own SPI flash and is updatable from the OS. The system's UEFI firmware is also able to access its configuration data in the flash - users are able to change the ...
- 414
1
vote
0
answers
791
views
How do you build a capsule in EDK2 and how do you put UEFI images inside that capsule?
I am testing around with EDK2 by Tianocore (https://github.com/tianocore/edk2) and I can build BIOS images as well as UEFI Applications and drivers but when it comes to building a UEFI capsule, I am ...
- 23
6
votes
1
answer
3k
views
Does UEFI replace standards like SMBIOS and ACPI? [closed]
I always wondered, as a developer with little experience in what goes on behind the OS, why is firmware such a mess. I'm trying to understand at least where the pieces fit. Is UEFI trying to replace ...
- 549
0
votes
0
answers
105
views
Would writing to full physical memory break the hardware?
I am playing around with UEFI and based on Specs after calling ExitBootServices i own all the memory. Are there any memory regions mapped by the CPU to some physical hardware ROMs that could be ...
user7145038
0
votes
1
answer
2k
views
EFI Application Erorr Write Protected
I tried to do some write/read operations on filesystems that I have enumerated for. The problem is when I want to write to other volumes rather than my self (fs0), it will return WRITE PROTECTED Error....
- 493
10
votes
1
answer
11k
views
How does processor read BIOS from SPI flash?
A typical x86 systems has firmware (aka BIOS or UEFI) stored in a SPI based Flash chip. When the power-on happens, the processor starts executing at Reset Vector which is pointing to memory-mapped SPI ...
- 8,234
1
vote
0
answers
119
views
How to add support for PCIe bridge to coreboot on Baytrail SoC
I Compiled Coreboot with Seabios and Tianocore payload on Baytrail SoC.
I want to use a PCIe bridge to convert a PCIE-x1 to 2 PCIE-X1 connectors
but booting FreeBSD won't show any active bridge.
The ...
- 11
2
votes
1
answer
2k
views
invalid UEFI volume when capturing AMI BIOS /ACPI 2.0
I want to backup BIOS. I use Universal BIOS Backup ToolKit V2.0.
Reading and backup are done without any error. When I want to open the captured BIOS .rom using UEFITool.exe the error occurs:
and ...
- 1,025
1
vote
1
answer
1k
views
UEFI variable size
I am storing persistent variables with UEFI. I am noticing weird behavior. Before I set the variable, I query MaximumVariableSize (with QueryVariableInfo) and I receive back a number, such as 65,000. ...
- 13.2k
0
votes
1
answer
469
views
TianoCore UEFI Development Kit build configuration, TargetTool produces unexpected configuration
I'm building UEFI application for x86-64 based board. My application shall be based on UDK2018 and utilizes its' build system. My build host is Ubuntu 17. I'm trying to use TargetTool to setup the ...
- 151
0
votes
2
answers
601
views
TianoCore UEFI Development Kit build: how to prevent the build process to ignore MS Windows - oriented stuff on Linux
I'm trying to build UDK2018 on Ubuntu 17. The platform build process (the Build base tool) unexpectedly tries to build some MS Windows oriented stuff and fails. How this can be fixed?
Following the ...
- 151
1
vote
0
answers
3k
views
Different ways to to trigger a SMI for a processor
I am writing some firmware code running in the System Managemnt Mode (SMM) on an Intel platform. I want to fully understand how my SMI handler get started.
I read from the Intel Manual that:
The ...
- 64k
-1
votes
1
answer
47
views
List of Programs that PC ROM have, Which supports the UEFI
List of programs that UEFI ROM have, And how to call them from other programs
2
votes
1
answer
1k
views
What does these ACPI names mean?
I dumped the ACPI tables on my laptop with the RW Everything. But I don't know what all these strange abbreviations mean.
I can guess _PR stands for processor, but where can I look up the others?
...
- 64k
1
vote
1
answer
618
views
Why the dumped processor number in ACPI tables is different from the actually installed processor?
My computer has an i5-4300U processor. It has 4 logical processors.
And the maximum cpu name is \_PR.CPU3:
According to the ACPI spec, one of the ACPI tables, the DSDT table (Differentiated System ...
- 64k
6
votes
2
answers
3k
views
Why do we need AML - ACPI Machine Language?
As I understand, ACPI defines a generic hardware programming model where operating system relies on the OEM firmware provided AML (ACPI machine language) code to manipulate the hardware.
In order to ...
- 64k
0
votes
2
answers
700
views
Is it possible to develop an operating system without a pre-existing one?
What I mean by this is if I have an "empty" computer (nothing in the disk) can I develop a program or more specifically an operating system without first installing a pre-existing one?
The question ...
- 361
0
votes
2
answers
595
views
What does "hardware register set" mean in ACPI?
I am reading an ACPI Introduction doc. It says:
ACPI can first be understood as an architecture independent power
management and configuration framework that forms a subsystem within
the host ...
- 64k
6
votes
4
answers
2k
views
Default UEFI boot order (in the firmware image)
Building a firmware using EDK2, what is the easiest way to provide a custom default boot order?
For instance, I know that Ovmf for QEMU redefines programmatically the UEFI boot order based on QEMU's "...
- 2,041
0
votes
1
answer
423
views
Finding ImageHandle of an uefi shell app. or module
I have a uefi shell app and a uefi module, providing similar functionality, I am trying to merge them into a single entity that can be executed either as a module from Boot Menu or from uefi shell.
Is ...
- 249
1
vote
1
answer
1k
views
tftp an application using uefi shell
I want to flash and upgrade my tianocore boot loader from the uefi shell.
Is it possible in this manner ?
download the tianocore firmware image from a server using tftpboot on uefi shell.
Erasing the ...
- 249
18
votes
6
answers
23k
views
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 "...
- 30.4k