86 lines
3.8 KiB
ReStructuredText
86 lines
3.8 KiB
ReStructuredText
|
.. SPDX-License-Identifier: GPL-2.0
|
||
|
|
|
||
|
|
Linux kernel for ARC processors
|
||
|
|
*******************************
|
||
|
|
|
||
|
|
Other sources of information
|
||
|
|
############################
|
||
|
|
|
||
|
|
Below are some resources where more information can be found on
|
||
|
|
ARC processors and relevant open source projects.
|
||
|
|
|
||
|
|
- `<https://embarc.org>`_ - Community portal for open source on ARC.
|
||
|
|
Good place to start to find relevant FOSS projects, toolchain releases,
|
||
|
|
news items and more.
|
||
|
|
|
||
|
|
- `<https://github.com/foss-for-synopsys-dwc-arc-processors>`_ -
|
||
|
|
Home for all development activities regarding open source projects for
|
||
|
|
ARC processors. Some of the projects are forks of various upstream projects,
|
||
|
|
where "work in progress" is hosted prior to submission to upstream projects.
|
||
|
|
Other projects are developed by Synopsys and made available to community
|
||
|
|
as open source for use on ARC Processors.
|
||
|
|
|
||
|
|
- `Official Synopsys ARC Processors website
|
||
|
|
<https://www.synopsys.com/designware-ip/processor-solutions.html>`_ -
|
||
|
|
location, with access to some IP documentation (`Programmer's Reference
|
||
|
|
Manual, AKA PRM for ARC HS processors
|
||
|
|
<https://www.synopsys.com/dw/doc.php/ds/cc/programmers-reference-manual-ARC-HS.pdf>`_)
|
||
|
|
and free versions of some commercial tools (`Free nSIM
|
||
|
|
<https://www.synopsys.com/cgi-bin/dwarcnsim/req1.cgi>`_ and
|
||
|
|
`MetaWare Light Edition <https://www.synopsys.com/cgi-bin/arcmwtk_lite/reg1.cgi>`_).
|
||
|
|
Please note though, registration is required to access both the documentation and
|
||
|
|
the tools.
|
||
|
|
|
||
|
|
Important note on ARC processors configurability
|
||
|
|
################################################
|
||
|
|
|
||
|
|
ARC processors are highly configurable and several configurable options
|
||
|
|
are supported in Linux. Some options are transparent to software
|
||
|
|
(i.e cache geometries, some can be detected at runtime and configured
|
||
|
|
and used accordingly, while some need to be explicitly selected or configured
|
||
|
|
in the kernel's configuration utility (AKA "make menuconfig").
|
||
|
|
|
||
|
|
However not all configurable options are supported when an ARC processor
|
||
|
|
is to run Linux. SoC design teams should refer to "Appendix E:
|
||
|
|
Configuration for ARC Linux" in the ARC HS Databook for configurability
|
||
|
|
guidelines.
|
||
|
|
|
||
|
|
Following these guidelines and selecting valid configuration options
|
||
|
|
up front is critical to help prevent any unwanted issues during
|
||
|
|
SoC bringup and software development in general.
|
||
|
|
|
||
|
|
Building the Linux kernel for ARC processors
|
||
|
|
############################################
|
||
|
|
|
||
|
|
The process of kernel building for ARC processors is the same as for any other
|
||
|
|
architecture and could be done in 2 ways:
|
||
|
|
|
||
|
|
- Cross-compilation: process of compiling for ARC targets on a development
|
||
|
|
host with a different processor architecture (generally x86_64/amd64).
|
||
|
|
- Native compilation: process of compiling for ARC on a ARC platform
|
||
|
|
(hardware board or a simulator like QEMU) with complete development environment
|
||
|
|
(GNU toolchain, dtc, make etc) installed on the platform.
|
||
|
|
|
||
|
|
In both cases, up-to-date GNU toolchain for ARC for the host is needed.
|
||
|
|
Synopsys offers prebuilt toolchain releases which can be used for this purpose,
|
||
|
|
available from:
|
||
|
|
|
||
|
|
- Synopsys GNU toolchain releases:
|
||
|
|
`<https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases>`_
|
||
|
|
|
||
|
|
- Linux kernel compilers collection:
|
||
|
|
`<https://mirrors.edge.kernel.org/pub/tools/crosstool>`_
|
||
|
|
|
||
|
|
- Bootlin's toolchain collection: `<https://toolchains.bootlin.com>`_
|
||
|
|
|
||
|
|
Once the toolchain is installed in the system, make sure its "bin" folder
|
||
|
|
is added in your ``PATH`` environment variable. Then set ``ARCH=arc`` &
|
||
|
|
``CROSS_COMPILE=arc-linux`` (or whatever matches installed ARC toolchain prefix)
|
||
|
|
and then as usual ``make defconfig && make``.
|
||
|
|
|
||
|
|
This will produce "vmlinux" file in the root of the kernel source tree
|
||
|
|
usable for loading on the target system via JTAG.
|
||
|
|
If you need to get an image usable with U-Boot bootloader,
|
||
|
|
type ``make uImage`` and ``uImage`` will be produced in ``arch/arc/boot``
|
||
|
|
folder.
|