CMakeLists.txt file for building the Einit program

The CMakeLists.txt file for building the Einit initializing program must contain the following commands:

• include (platform/image) connects the CMake library that contains the solution image build scripts.
• project_header_default ("STANDARD_GNU_11:YES" "STRICT_WARNINGS:NO") sets the flags of the compiler and linker.
• Configure the packages of system programs and drivers that need to be included in the solution.
  • A package is connected by using the find_package () command.
  • For some packages, you must also set the values of properties by using the set_target_properties () command.

  CMake descriptions of system programs and drivers provided in KasperskyOS Community Edition, and descriptions of their exported variables and properties are located in the corresponding files at /opt/KasperskyOS-Community-Edition-<version>/sysroot-aarch64-kos/lib/cmake/<program name>/<program name>-config.cmake

• To automatically add descriptions of IPC channels between processes of system programs to the init.yaml file when building a solution, you must add these channels to the EXTRA_CONNECTIONS property for the corresponding programs.

  For example, the VFS program does not have a channel for connecting to the Env program by default. To automatically add a description of this channel to the init.yaml file during a solution build, you must add the following call to the CMakeLists.txt file for building the Einit program:

  set_target_properties (${vfs_ENTITY} PROPERTIES

  EXTRA_CONNECTIONS

  " - target: env.Env

  id: {var: ENV_SERVICE_NAME, include: env/env.h}"

  When building this solution, the description of this IPC channel will be automatically added to the init.yaml file when processing macros of the init.yaml.in template.

• To automatically add a list of arguments for the main() function and a dictionary of environment variables to the init.yaml file when building a solution, you must define the EXTRA_ARGS and EXTRA_ENV properties and assign the appropriate values to them.

Example of sending the VfsEntity program the "-f fstab" argument of the main() function and the environment variable ROOTFS set to ramdisk0,0 / ext2 0:

set_target_properties (${vfs_ENTITY} PROPERTIES

EXTRA_ARGS

" - \"-f\"

- \"fstab\""

EXTRA_ENV

" ROOTFS: ramdisk0,0 / ext2 0")

When building this solution, the description of the main() function argument and the environment variable value will be automatically added to the init.yaml file when processing macros of the init.yaml.in template.

• set(ENTITIES <full list of programs included in the solution>) defines the ENTITIES variable containing a list of executable files of all programs included in the solution.
• One or both commands for building the solution image:
  • build_kos_hw_image() creates the build target that can then be used to build the image for the hardware platform using make.
  • build_kos_qemu_image() creates the build target that can then be used to build the image for running in QEMU using make.

Example CMakeLists.txt file for building the Einit program

CMakeLists.txt

project (einit)

# Connect the library containing solution image build scripts.

include (platform/image)

# Set compile flags.

project_header_default ("STANDARD_GNU_11:YES" "STRICT_WARNINGS:NO")

# Configure the VFS program.

# By default, the VFS program is not mapped to a program implementing a block device.

# If you need to use a block device, such as ata from the ata component,

# you must define this device in the variable ${blkdev_ENTITY}_REPLACEMENT

# For more information about exported variables and properties of the VFS program,

# see /opt/KasperskyOS-Community-Edition-<version>/sysroot-aarch64-kos/lib/cmake/vfs/vfs-config.cmake

# find_package(ata)

# set_target_properties (${vfs_ENTITY} PROPERTIES ${blkdev_ENTITY}_REPLACEMENT ${ata_ENTITY})

# In the simplest case, you do not need to interact with a drive.

# For this reason, we set the value of the ${blkdev_ENTITY}_REPLACEMENT variable equal to an empty string

set_target_properties (${vfs_ENTITY} PROPERTIES ${blkdev_ENTITY}_REPLACEMENT "")

# Define the ENTITIES variable with a list of executable files of programs.

# It is important to include all programs that are part of the project, except the Einit program.

# Please note that the name of the executable file of a program must

# match the name of the target indicated in add_executable() in the CMakeLists.txt file for building this program.

set(ENTITIES

${vfs_ENTITY}

Hello_app

)

# Solution image for target hardware platform.

# Create the build target named kos-image that can then be used

# to build the image for the hardware platform using make kos-image.

build_kos_hw_image (kos-image

EINIT_ENTITY EinitHw

CONNECTIONS_CFG "src/init.yaml.in" # template of the init.yaml file

SECURITY_PSL "src/security.psl.in" # template of the security.psl file

IMAGE_FILES ${ENTITIES}

)

# Solution image for the QEMU hardware platform.

# Create the build target named kos-qemu-image that can then be used

# to build a QEMU image using make kos-qemu-image.

build_kos_qemu_image (kos-qemu-image

EINIT_ENTITY EinitQemu

CONNECTIONS_CFG "src/init.yaml.in"

SECURITY_PSL "src/security.psl.in"

IMAGE_FILES ${ENTITIES}

)