How Can I jump from EL1 to EL0 in bare metal environment

Awax

Hello,

I am working with a port of FreeRTOS on Arm64 soc , which is running at EL1, my goal is to perform a function call that will execute in EL0,

I have come to understand that the only way for the EL switch is to set the correct M bits of the spsr_el1…

Answered

Why ARM does not support 64bit for faulting address of IPA?

YOO JEUNGWOO

I'm trying to understand how ARM architecture(ARMv8) support for faulting address in the virtualization environment. For the hypervisor, every device access from the guest must be trapped to emulate a device.

The memory access from the guest will…

Answered

What are the necessary preconditions to load a guest into EL1 from EL2?

Branden Sherrell

I have successfully moved from EL3 to EL2. After doing some initialization I am trying to move from EL2 into EL1 with a very simple guest image. My process looks like:

Map EL1 memory into EL2
Copy EL1 image to RAM
Initialize sctlr_el1 = 0x30d00800

…

Answered

armv7a/armv8 : Undefined Abort Exception and MMU

Vincent Siles

Hi !

When MMU is enabled, and a undefined abort exception is triggered, are we sure that the address stored in the `lr` / `elr_elx` registers is actually mapped by the MMU, or should I check that before trying to access the address ?

Best,

V.

Answered

Changing Exception Level and Security State with an Armv8-A Fixed Virtual Platform

tmeduthie

In my last couple of blogs we built an ELF image to expose some features of the Armv8-A architecture and toolchain for embedded software development. We got to a point where we could print "hello world" to a telnet console, and enable interrupts on the…

Transition to secure monitor flow on ARMv8

Umair Khan

Hi everyone,

Wherever I go on internet, the thing I read is that when SMC instruction is executed an exception is generated, it takes you to the highest exception level (EL3) where secure monitor is running.

In ARM v8 vector table, given on ARMv8-A architecture…

Answered

SMC flow on ARMv8

Umair Khan

Hi everyone,

Wherever I go on internet, the thing I read is that when SMC instruction is executed an exception is generated, it takes you to the highest exception level (EL3) where secure monitor is running.

In ARM v8 vector table, given on ARMv8-A architecture…

Answered

Transition to secure monitor flow on ARMv8

Umair Khan

Hi everyone,

Wherever I go on internet, the thing I read is that when SMC instruction is executed an exception is generated, it takes you to the highest exception level (EL3) where secure monitor is running.

In ARM v8 vector table, given on ARMv8-A architecture…

Answered

ARMv8-A的SP_EL0的安全？

chendader

在ARMv8-A中，EL1/2/3除了可以自身的堆栈寄存器SP_ELn以外，还可以使用SP_EL0。

与此同时EL0也可以使用SP_EL0。

我想在EL0的应用程序应该可以通过SP_EL0，访问到EL1/2/3的数据，这岂不是不安全？

希望帮忙解答，谢谢！

over 3 years ago
中文社区
中文社区论区

How to ensure the safety of SP_EL0

chendader

Hi experts，

In ARMv8, EL1/2/3 can use either their own stack pointer, SP_ELx or SP_EL0.

SP_EL0 can be used in EL0.

why it is safe to use SP_EL0 in EL1/2/3? I think the applications in EL0 may get the data of kernel in EL1 through SP_EL0.

Can anybody…