Re: [PATCH 3/4] external-arm-toolchain: Add README

["Denys Dmytriyenko" <denis@denix.org>]

On Tue, Jun 02, 2020 at 04:34:53PM +0530, Sumit Garg wrote:
> Document usage details for pre-built Arm toolchains.
> 
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> ---
>  .../external-arm-toolchain/README.md               | 50 ++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
>  create mode 100644 meta-arm-toolchain/recipes-devtools/external-arm-toolchain/README.md
> 
> diff --git a/meta-arm-toolchain/recipes-devtools/external-arm-toolchain/README.md b/meta-arm-toolchain/recipes-devtools/external-arm-toolchain/README.md
> new file mode 100644
> index 0000000..65d1a42
> --- /dev/null
> +++ b/meta-arm-toolchain/recipes-devtools/external-arm-toolchain/README.md
> @@ -0,0 +1,50 @@
> +Pre-built Arm toolchain recipes
> +===============================
> +
> +Introduction
> +------------
> +This layer contains recipes for pre-built Arm toolchain recipes as follows:
> +
> +external-arm-toolchain.bb
> +~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +This recipe provides support for pre-built GNU toolchains targeting processors
> +from the Arm Cortex-A family and implementing the Arm A-profile architecture.
> +
> +Usage
> +^^^^^
> +
> +In order to use any of pre-built Arm toolchain versions (8.2, 8.3, 9.2 and so
> +on), a user needs to download and untar tool-set on host machine at a particular
> +installation path eg: ``/opt/toolchain/``. Then user needs to specify following
> +in ``conf/local.conf`` in order to replace OE toolcahin with pre-built GNU-A
> +toolchain:
> +
> +TCMODE = "external-arm"
> +EXTERNAL_TOOLCHAIN = "<path-to-the-toolchain>"
> +
> +-  Eg. for AArch64 (eg. qemuarm64 machine in poky distro)
> +   EXTERNAL_TOOLCHAIN = "\
> +     <installation-path>/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu \
> +   "
> +
> +-  Eg. for AArch32 (eg. qemuarm machine in poky distro)
> +   EXTERNAL_TOOLCHAIN = "\
> +     <installation-path>/gcc-arm-9.2-2019.12-x86_64-arm-none-linux-gnueabihf \
> +   "
> +
> +Supported distros and machines
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Since this pre-built GNU-A tool-set simply replaces OE toolchain, so it is
> +meant to be distro and machine agnostic as long as one is cross-compiling for
> +Arm A-profile architecture.
> +
> +gcc-arm-none-eabi_<version>.bb
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

gcc-aarch64-none-elf?

Probably need to explain a bit more regarding the differences between 
baremetal and Linux toolchains, as currently it can be confusing to some 
why there are 2 sets of toolchain recipes...


> +This recipe provides support for pre-built GNU Arm Embedded toolchain for
> +bare-metal software development on devices based on 32-bit Arm Cortex-A,
> +Cortex-R and Cortex-M processors.
> +
> +Supported version: 9-2019-q4-major
> -- 
> 2.7.4
>