Add an LLVM backend and a clang toolchain variant to support building
with llvm coming with popular Linux distributions.
This has been tested with X86 boards:
- quark_d2000_crb
- quark_se_c1000_devboard/Arduino 101
Use:
export ZEPHYR_TOOLCHAIN_VARIANT=clang
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
In order to mitigate against Spectre V4, add an option that will, at
boot time, verify if the CPU supports the SPEC_CTRL MSR; if so, it'll
attempt to disable the feature.
More information can be found in chapter 4 (Speculative Store Bypass
Mitigation) of the "Speculative Execution Side Channel Mitigations"
document, version 2, published by Intel: https://goo.gl/nocTcj
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Rename _MsrRead() and _MsrWrite() to _x86_msr_read() and
_x86_msr_write() respectively.
Given that these functions are essentially implemented in assembly.
make them static inline. They can be inlined by the compiler quite
well, most of the time incurring in space savings due to better
handling of the cobbled registers.
Also simplifies the inline assembly, using constraints instead of
moving registers ourselves. Should shave off a few bytes from code
using these functions.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Normally a syscall would check the current privilege level and then
decide to go to _impl_<syscall> directly or go through a
_handler_<syscall>.
__ZEPHYR_SUPERVISOR__ is a compiler optimization flag which will
make all the system calls from the arch files directly link
to the _impl_<syscall>. Thereby reducing the overhead of checking the
privileges.
In the previous implementation all the source files would be compiled
by zephyr_source() rule. This means that zephyr_* is a catchall CMake
library for source files that can be built purely with the include
paths, defines, and other compiler flags that all zephyr source
files uses. This states that adding one extra compiler flag for only
one complete directory would fail.
This limitation can be overcome by using zephyr_libray* APIs. This
creates a library for the required directories and it also supports
directory level properties.
Hence we use zephyr_library* to create a new library with
macro _ZEPHYR_SUPERVISOR_ for the optimization.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
This feature is X86 only and is not used or being tested. It is legacy
feature and no one can prove it actually works. Remove it until we have
proper documentation and samples and multi architecture support.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Introducing CMake is an important step in a larger effort to make
Zephyr easy to use for application developers working on different
platforms with different development environment needs.
Simplified, this change retains Kconfig as-is, and replaces all
Makefiles with CMakeLists.txt. The DSL-like Make language that KBuild
offers is replaced by a set of CMake extentions. These extentions have
either provided simple one-to-one translations of KBuild features or
introduced new concepts that replace KBuild concepts.
This is a breaking change for existing test infrastructure and build
scripts that are maintained out-of-tree. But for FW itself, no porting
should be necessary.
For users that just want to continue their work with minimal
disruption the following should suffice:
Install CMake 3.8.2+
Port any out-of-tree Makefiles to CMake.
Learn the absolute minimum about the new command line interface:
$ cd samples/hello_world
$ mkdir build && cd build
$ cmake -DBOARD=nrf52_pca10040 ..
$ cd build
$ make
PR: zephyrproject-rtos#4692
docs: http://docs.zephyrproject.org/getting_started/getting_started.html
Signed-off-by: Sebastian Boe <sebastian.boe@nordicsemi.no>
Anas Nashif