6baeeaef21
The implementation of single-stepping on ARMv7 relies on instruction mismatch breakpoints. The implementation sets one of the breakpoint value registers (BVR) to NULL and configures the corresponding breakpoint control register (BCR) to generate a debug exception for instructions that are at any other virtual address. This is incorrect as it means that when single-stepping is enabled, no progress will ever be made by the thread, as every instruction will mismatch with NULL and result in the generation of a debug exception. This commit resolves this issue by setting the BVR to the LR of the thread at the moment single stepping is configured. Then, when the thread is permitted to execute again, the instruction pointed to by the LR will be executed, but any other instruction will result in a debug exception. It also changes the debug exception hander to update the BVR to the new LR when a single-stepping execption occurs so that we can step over multiple instructions before sending a debug fault to the appropriate fault handler thread. Signed-off-by: Alwin Joshy <joshyalwin@gmail.com>
The seL4 microkernel
This project contains the source code of seL4 microkernel.
For details about the seL4 microkernel, including details about its formal
correctness proof, please see the sel4.systems website and associated
FAQ.
DOIs for citing recent releases of this repository:
We welcome contributions to seL4. Please see the website for information on how to contribute.
This repository is usually not used in isolation, but as part of the build system in a larger project.
seL4 Basics
- Tutorials
- Documentation
- seL4 libraries
- seL4Test
- Debugging guide
- Benchmarking guide
- Virtualization on seL4
- Host Build Dependencies
- Porting seL4
Community
See the contact links on the seL4 website for the full list.
Reporting security vulnerabilities
If you believe you have found a security vulnerability in seL4 or related software, we ask you to follow our vulnerability disclosure policy.
Manual
A hosted version of the manual for the most recent release can be found here.
A web version of the API can be found here
Repository Overview
includeandsrc: C and ASM source code of seL4tools: build toolslibsel4: C bindings for the seL4 ABImanual: LaTeX sources of the seL4 reference manual
Build Instructions
See the seL4 website for build instructions.
Status
A list of releases and current project status can be found under seL4 releases.
- Roadmap: new features in development
- Hardware Support: information about hardware platform ports
- Kernel Features: information about available kernel features
- Userland Components and Drivers: available device drivers and userland components
License
See the file LICENSE.md.