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.

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:

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.