This is documentation for the development version of the project, aka master branch. If you installed Gramine from packages, documentation for the stable version is available at


Gramine consists of several components:

  • The Library OS itself (a shared library named, called the “shim” in our source code)
  • The Platform Adaptation Layer, or PAL (a shared library named
  • A patched C Library (shared library and possibly others). Currently there are two options: musl and GNU C Library (glibc).

The build of Gramine implies building at least the first two components. The build of the patched C library is optional but highly recommended for performance reasons. Both patched glibc and patched musl are built by default.

Gramine currently only works on the x86_64 architecture. Gramine is currently tested on Ubuntu 18.04/20.04, along with Linux kernel version 5.x. We recommend building and installing Gramine on Ubuntu with Linux kernel version 5.11 or higher. If you find problems with Gramine on other Linux distributions, please contact us with a detailed bug report.

Installing dependencies

Common dependencies

Run the following command on Ubuntu LTS to install dependencies:

sudo apt-get install -y build-essential \
    autoconf bison gawk nasm ninja-build python3 python3-click \
    python3-jinja2 wget
sudo python3 -m pip install 'meson>=0.55' 'toml>=0.10'

You can also install Meson and python3-toml from apt instead of pip, but only if your distro is new enough to have Meson >= 0.55 and python3-toml >= 0.10 (Debian 11, Ubuntu 20.10).

For GDB support and to run all tests locally you also need to install:

sudo apt-get install -y libunwind8 musl-tools python3-pyelftools \

If you want to build the patched libgomp library, you also need to install GCC’s build dependencies:

sudo apt-get install -y libgmp-dev libmpfr-dev libmpc-dev libisl-dev

Dependencies for SGX

The build of Gramine with SGX support requires the corresponding SGX software infrastructure to be installed on the system. In particular, the FSGSBASE functionality must be enabled in the Linux kernel, the Intel SGX driver must be running, and Intel SGX SDK/PSW/DCAP must be installed.


We recommend to use Linux kernel version 5.11 or higher: starting from this version, Linux has the FSGSBASE functionality as well as the Intel SGX driver built-in. If you have Linux 5.11+, skip steps 2 and 3.

1. Required packages

Run the following commands on Ubuntu to install SGX-related dependencies:

sudo apt-get install -y libcurl4-openssl-dev libprotobuf-c-dev \
    protobuf-c-compiler python3-cryptography python3-pip python3-protobuf

2. Install Linux kernel with patched FSGSBASE

FSGSBASE is a feature in recent processors which allows direct access to the FS and GS segment base addresses. For more information about FSGSBASE and its benefits, see this discussion. Note that if your kernel version is 5.9 or higher, then the FSGSBASE feature is already supported and you can skip this step. Kernel version can be checked using the following command:

uname -r

If your current kernel version is lower than 5.9, then you have two options:

  • Update the Linux kernel to at least 5.9 in your OS distro. If you use Ubuntu, you can follow e.g. this tutorial.
  • Use our provided patches to the Linux kernel version 5.4. See section Prepare a signing key for the exact steps.

3. Install the Intel SGX driver

This step depends on your hardware and kernel version. Note that if your kernel version is 5.11 or higher, then the Intel SGX driver is already installed and you can skip this step.

If you have an older CPU without FLC support, you need to download and install the the following out-of-tree (OOT) Intel SGX driver:

For this driver, you need to set vm.mmap_min_addr=0 in the system (only required for the legacy SGX driver and not needed for newer DCAP/in-kernel drivers):

sudo sysctl vm.mmap_min_addr=0

Note that this is an inadvisable configuration for production systems.

Alternatively, if your CPU supports FLC, you can choose to install the DCAP version of the Intel SGX driver from:

4. Install Intel SGX SDK/PSW

Follow the installation instructions from:

5. Install dependencies for DCAP

If you plan on enabling -Ddcap option, you need to install libsgx-dcap-quote-verify package (and it’s development counterpart):

curl -fsSL | sudo apt-key add -
echo 'deb [arch=amd64] focal main' | sudo tee /etc/apt/sources.list.d/intel-sgx.list
# (if you're on Ubuntu 18.04, write "bionic" instead of "focal" above)

sudo apt-get update
sudo apt-get install libsgx-dcap-quote-verify-dev


In order to build Gramine, you need to first set up the build directory. In the root directory of Gramine repo, run the following command (recall that “direct” means non-SGX version):

meson setup build/ --buildtype=release -Ddirect=enabled -Dsgx=enabled \
    -Dsgx_driver=<driver> -Dsgx_driver_include_path=<path-to-sgx-driver-sources>


If you plan to contribute changes to Gramine, then you should always build it with --werror added to the invocation above.


If you invoked meson setup once, the next invocation of this command will not have any effect. Instead, to change the build configuration, use meson configure. For example, if you built with meson setup build/ -Dsgx=disabled first and now want to enable SGX, type meson configure build/ -Dsgx=enabled.

Then, build and install Gramine by running the following:

ninja -C build/
sudo ninja -C build/ install

Set -Ddirect= and -Dsgx= options to enabled or disabled according to whether you built the corresponding PAL (the snippet assumes you built both).

The -Dsgx_driver parameter controls which SGX driver to use:

  • upstream (default) for upstreamed in-kernel driver (mainline Linux kernel 5.11+),
  • dcap1.6 for Intel DCAP version 1.6 or higher, but below 1.10,
  • dcap1.10 for Intel DCAP version 1.10 or higher,
  • oot for non-DCAP, out-of-tree version of the driver.

The -Dsgx_driver_include_path parameter must point to the absolute path where the SGX driver was downloaded or installed in the previous step. For example, for the DCAP version 1.41 of the SGX driver, you must specify -Dsgx_driver_include_path="/usr/src/sgx-1.41/include/". If this parameter is omitted, Gramine’s build system will try to determine the right path.


When installing from sources, Gramine executables are placed under /usr/local/bin. Some Linux distributions (notably CentOS) do not search for executables under this path. If your system reports that Gramine programs can not be found, you might need to edit your configuration files so that /usr/local/bin is in your path (in PATH environment variable).

Set -Dglibc= or -Dmusl= options to disabled if you wish not to build the support for any (they are both built by default).

Additional build options

  • To build test binaries, run meson -Dtests=enabled. This is necessary if you will be running regression tests. See Contributing to Gramine for details.

  • In order to run SGX tools with DCAP version of RA-TLS library (, build with meson -Ddcap=enabled option. See RA-TLS example’s README.


    EPID version of RA-TLS library ( is built by default.

  • To create a debug build, run meson --buildtype=debug. This adds debug symbols in all Gramine components, builds them without optimizations, and enables detailed debug logs in Gramine.


    Debug builds are not suitable for production.

  • To create a debug build that does not disable optimizations, run meson --buildtype=debugoptimized.


    Debug builds are not suitable for production.


    This is generally not recommended, because optimized builds lose some debugging information, and may cause GDB to display confusing tracebacks or garbage data. You should use DEBUGOPT=1 only if you have a good reason (e.g. for profiling).

  • To compile with undefined behavior sanitization (UBSan), run meson -Dubsan=enabled. This causes Gramine to abort when undefined behavior is detected (and display information about source line). UBSan can be enabled for both debug and non-debug builds.


    UBSan builds (even non-debug) are not suitable for production.

  • To compile with address sanitization (ASan), run meson -Dasan=enabled. In this mode, Gramine will attempt to detect invalid memory accesses. ASan can be enabled for both debug and non-debug builds.

    ASan is supported only when compiling with Clang (before building, set the appropriate environment variables with export CC=clang CXX=clang++ AS=clang).


    ASan builds (even non-debug) are not suitable for production.

  • To build with -Werror, run meson --werror.

  • To install into some other place than /usr/local, use meson --prefix=<prefix>. Note that if you chose something else than /usr then for things to work, you probably need to adjust several environment variables:

    Variable What to add Read more
    $PATH <prefix>/bin POSIX.1-2018 8.3
    $PYTHONPATH <prefix>/lib/python<version>/site-packages python3(1)
    $PKG_CONFIG_PATH <prefix>/<libdir>/pkgconfig pkg-config(1)

    This very much depends on particular distribution, so please consult relevant documentation provided by your distro.

  • To compile a patched version of GCC’s OpenMP library (libgomp), install GCC’s build prerequisites (see Common dependencies), and use meson -Dlibgomp=enabled.

    The patched version has significantly better performance under SGX (libgomp uses inline SYSCALL instructions for futex calls; our patch replaces them with a jump to Gramine LibOS, same as for glibc).

    Building the patched libgomp library is disabled by default because it can take a long time: unfortunately, the only supported way of building libgomp is as part of a complete GCC build.

Prepare a signing key

Only for SGX enclave development, and if you haven’t already, run the following command:


This command generates an RSA 3072 key suitable for signing SGX enclaves and stores it in HOME/.config/gramine/enclave-key.pem. This key needs to be protected and should not be disclosed to anyone.

After signing the application’s manifest, users may ship the application and Gramine binaries, along with an SGX-specific manifest (.manifest.sgx extension), the SIGSTRUCT signature file (.sig extension), and the EINITTOKEN file (.token extension) to execute on another SGX-enabled host.

Advanced: installing Linux kernel with FSGSBASE patches

FSGSBASE patchset was merged in Linux kernel version 5.9. For older kernels it is available as separate patches. (Note that Gramine was prevously called Graphene and was hosted under a different organization, hence the name of the linked repository.)

The following instructions to patch and compile a Linux kernel with FSGSBASE support below are written around Ubuntu 18.04 LTS (Bionic Beaver) with a Linux 5.4 LTS stable kernel but can be adapted for other distros as necessary. These instructions ensure that the resulting kernel has FSGSBASE support.

  1. Clone the repository with patches:

    git clone
  2. Setup a build environment for kernel development following the instructions in the Ubuntu wiki. Clone Linux version 5.4 via:

    git clone --single-branch --branch linux-5.4.y \
    cd linux
  3. Apply the provided FSGSBASE patches to the kernel source tree:

    git am <graphene-sgx-driver>/fsgsbase_patches/*.patch

    The conversation regarding this patchset can be found in the kernel mailing list archives here.

  4. Build and install the kernel following the instructions in the Ubuntu wiki.

  5. After rebooting, verify the patched kernel is the one that has been booted and is running:

    uname -r
  6. Also verify that the patched kernel supports FSGSBASE (the below command must return that bit 1 is set):

    # Linux kernel doesn't support FSGSBASE: patch or use higher version!
    $ LD_SHOW_AUXV=1 /bin/true | grep AT_HWCAP2
    AT_HWCAP2:       0x0
    # Linux kernel supports FSGSBASE (example where only bit 1 is set)
    $ LD_SHOW_AUXV=1 /bin/true | grep AT_HWCAP2
    AT_HWCAP2:       0x2

After the patched Linux kernel is installed, you may proceed with installations of other SGX software infrastructure: the Intel SGX Linux driver, the Intel SGX SDK/PSW, and Gramine itself.