second-state / wasmedge-sel4-projects

camkes-vm

The CAmkES VMM is actively targeted to run on the C162 platform from Aitech. This repo provides various CAmkES components, templates, interfaces and libraries that can be used to create a CAmkES VMM application. This is short description of how to use and build with this project.

Build dependencies

To ensure you have the necessary dependencies for building the CAmkES VM project please refer to the Host Dependencies page.

CMake

To build an application with this project we use CMake. This repo provides a series of CMake helper functions (found in camkes_vm_helpers.cmake) to assit you with defining your CAmkES VM application. Importing this file into your applications CMake configuration gives you access to the following helper functions:

• DeclareCAmkESVM(init_component [SOURCES INCLUDES LIBS LD_FLAGS C_FLAGS]): Function for declaring a CAmkESVM. This is called for each Init component in the defined in the applications .camkes file. The user can also pass in extra compilation sources, includes, libs and flags to be compiled with the component through additional arguments (SOURCES, INCLUDES, LIBS, LD_FLAGS and C_FLAGS)
• DeclareCAmkESVMRootServer(camkes_config): Declares the CAmkESVM root server. This function takes the applications .camkes file as an argument (camkes_config).
• AddToFileServer(filename_pref file_dest [DEPENDS]): Function for adding a file/image to the vm file server. The caller specifies the name of they wish to refer to the image in the FileServer through the filename_pref parameter. file_dest is the file system location of the image the caller is adding. Additional dependencies to the image can be passed through the optional DEPENDS parameter.
• DecompressLinuxKernel(decompress_target decompressed_kernel_image compressed_kernel_image [DEPENDS]): Function for decompressing/extracting a vmlinux file from a given kernel image. The caller specifies a target name (decompress_target) for decompressing the kernel, the kernel image to decompress (compressed_kernel_image) and additional dependencies to the compressed image through the optional DEPENDS parameter. The location of the decompressed image is populated in the decompressed_kernel_image parameter passed by the caller.

Items

This repo contains a series of CAmkES components, templates, libraries and images necessary to develop a CAmkES VM application. This project does not contain any CAmkES VM applications to build however. A set of example CAmkES VM applications can be found in the camkes-vm-examples repo. This is a small description of the various items provided in this repository:

CAmkES Components

This repo provides a series of useful CAmkES components that can be used to develop your VM platform, in addition to some demonstration applications. These components include:

• Init
• Ethdriver
• StringReverse
• Echo
• Firewall
• StringReverse
• UDPServer

Linux Images

This repo provides Guest Linux VM images you can use for your CAmkES VM application, located in the linux directory. We provide a ready-to-use Rootfs (linux/rootfs.cpio) and Kernel image (linux/bzimage) built from the buildroot project.

Additionally you can develop your own applications and linux kernel modules to add to the Linux rootfs.cpio archive. After making changes and adding additional packages and modules you can run the provided build-rootfs tool to generate a new rootfs image.

Libraries

libcrossvm

libcrossvm makes it possible connect processes in the guest linux to a regular CAmkES component. This is achieved through making dataports and event interfaces available to the guest VM. To utilise the CAmkES Cross VM connector implementation we provide the crossvm library.

To enable a guest Linux with crossvm functionality we can link the library to the desired VMs CMake declaration, for example: DeclareCAmkESVM(Init0 EXTRA_LIBS crossvm )

Serial

The hardware COM1 is multiplexed to each VM such that output for each guest and VM appears over COM1, and input can be directed at any of the guests. The output of each guest and VM is colour coded.

By default input is sent to vm0, to switch input to a different VM use @N where N is 0-9 (for VMs 0 to 9) or :,; for VMs 10 and 11 respectively. The escape character, tilde, is only recognized following a newline. To get a list of all supported escapes, use @?.

It is also possible to send input to multiple VMs at the same time. This mode is experimental. To set up multi-guest input, use @m followed by one or more numbers or characters (as above), then press Return to apply.

Multi-guest input mode also enables output coalescing, in order to allow convenient use of the shell and other interactive terminal applications (including text editors, if the editor state is exactly the same in all guests). Coalesced output is drawn in white. Please note that coalescing is experimental and best-effort; some circumstances will result in coalescing failure, which is shown as multiple colour-coded copies of the same output. In order to ameliorate this, it is recommended to use a terminal multiplexer such as screen inside the VMs, providing a redraw function.

Some debug features are also built in (activated via the @d escape); see the online help (@?) and the source code for details.