Cadence Tensilica Xtensa C/C++ Compiler (XCC)

1. Obtain Tensilica Software Development Toolkit targeting the specific SoC on hand. This usually contains two parts:

   • The Xtensa Xplorer which contains the necessary executables and libraries.

   • A SoC-specific add-on to be installed on top of Xtensa Xplorer.

     • This add-on allows the compiler to generate code for the SoC on hand.

2. Install Xtensa Xplorer and then the SoC add-on.

   • Follow the instruction from Cadence on how to install the SDK.

   • Depending on the SDK, there are two set of compilers:

     • GCC-based compiler: xt-xcc and its friends.

     • Clang-based compiler: xt-clang and its friends.

3. Make sure you have obtained a license to use the SDK, or has access to a remote licensing server.

4. Set these environment variables:

   • Set ZEPHYR_TOOLCHAIN_VARIANT to xcc or xt-clang.

   • Set XTENSA_TOOLCHAIN_PATH to the toolchain installation directory.

   • There are two ways to specify the SoC ID and the SDK version to use. They are mutually exclusive, and cannot be used together.

     1. When building for a single SoC:

        • Set XTENSA_CORE to the SoC ID where application is being targeted.

        • Set TOOLCHAIN_VER to the Xtensa SDK version.

     2. When building for multiple SoCs, for each SoC and board combination:

        • Set XTENSA_CORE_{normalized_board_target} to the SoC ID where application is being targeted.

        • Set TOOLCHAIN_VAR_{normalized_board_target} to the Xtensa SDK version.

5. For example, assuming the SDK is installed in /opt/xtensa, and using the SDK for application development on intel_adsp/ace15_mtpm, setup the environment using the two above mentioned ways:

   1. Single SoC:

      # Linux
      export ZEPHYR_TOOLCHAIN_VARIANT=xt-clang
      export XTENSA_TOOLCHAIN_PATH=/opt/xtensa/XtDevTools/install/tools/
      export XTENSA_CORE=ace10_LX7HiFi4_2022_10
      export TOOLCHAIN_VER=RI-2022.10-linux
      

   2. Multiple SoCs:

      # Linux
      export ZEPHYR_TOOLCHAIN_VARIANT=xt-clang
      export XTENSA_TOOLCHAIN_PATH=/opt/xtensa/XtDevTools/install/tools/
      export TOOLCHAIN_VER_intel_adsp_ace15_mtpm=RI-2022.10-linux
      export XTENSA_CORE_intel_adsp_ace15_mtpm=ace10_LX7HiFi4_2022_10
      

6. To use Clang-based compiler:

   • Set ZEPHYR_TOOLCHAIN_VARIANT to xt-clang.

   • Note that the Clang-based compiler may contain an old LLVM bug which results in the following error:

     /tmp/file.s: Assembler messages:
     /tmp/file.s:20: Error: file number 1 already allocated
     clang-3.9: error: Xtensa-as command failed with exit code 1
     

     If this happens, set XCC_NO_G_FLAG to 1.

     • For example:

       # Linux
       export XCC_NO_G_FLAG=1