3fe1ee40b2
The LLVM Target parser currently does not allow to specify the security extension as part of -march (see also LLVM Bug 40186 [0]). When trying to use Clang with LLVM's integrated assembler, this leads to build errors such as this: clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec' Use ".arch_extension sec" to enable the security extension in a more portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7 multi-platform kernel is being built. Note that this is technically not exactly the same as the old code checked for availabilty of the security extension by calling as-instr. However, there are already other sites which use ".arch_extension sec" unconditionally, hence de-facto we need an assembler capable of ".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The arch extension "sec" is available since binutils 2.21 according to its documentation [1]. [0] https://bugs.llvm.org/show_bug.cgi?id=40186 [1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Mans Rullgard <mans@mansr.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Olof Johansson <olof@lixom.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.