Armv8 Architecture: Exception Level and Exception state
Exception Level and Exception state in Cortex-A based Processor(Armv8-Aarch64)
Description
Smartphones, AI System-on-Chip (SoC), Electric Vehicle Automotive (Infotainment, Autonomous Driving), and Arm processors used in cloud servers and MacBooks are all based on the Armv8-A architecture, which is a 64-bit Cortex-A processor (e.g., Cortex-A53, Cortex-A57, Cortex-A72). Currently, in the system software industry, knowledge of the Armv8-A architecture is considered essential as it is in high demand.
This lecture covers the Exception level, that is the key feature of Armv8-A architecture necessary for the development of software systems.
Concept of Exception level
How to change Exception level
System register to identify current Exception Level
Assembly routine to read current Exception Level
The execution state in Armv8
To understand entire features of Armv8, the first concept to know is Exception level. This lecture explains the details of Exception level by explaining 'how to change its exception level' and 'relevant system register(CurrentEL)' to identify current Exception level.
In addition the workflow is exception in Armv8 is introduced as a way to understand how exception level is changed. The reference code is analyzed based on XEN and Linux kernel.
In general, a piece of software, such as an application, the kernel of an operating system, or a hypervisor, occupies a single Exception level. So understanding of Exception level is crucial.
What You Will Learn!
- The basic concept of Exception level in Armv8
- How Exception levels are used in Linux system
- How Exception levels are switched during boot sequence
- The way to identify the current Exception level in the system
- Assembly routine to read current Exception level in Linux kernel and XEN hypervisor
Who Should Attend!
- Professionals interested in exploring Embedded systems
- Professionals interested in exploring Armv8 architecture
- Hobbyists and students who want to start their career in Embedded world
- If you think about 'embedded' then think about taking this course. you will not be disappointed