PolkaVM Examples

How to run different languages in PolkaVM. All examples use the Dockerfile to get a clang-18 compiler with correct RISC support.

The project uses just to run commands. Try it with:

cargo install just
just docker # or podman
just

Universal PVM Executor

The pvme folder contains a small CLI that can be used to run PVM programs and inject mocked host calls.
Its functionality is currently limited to u32 types for arguments and return.

For example, call the entry function with arguments 42 and 69 and provide a host function that returns 100:

cd pvme
cargo r -- call ../test.pvm entry 42 69 --host-functions "get_third_number:100"

Languages

• C: lang-c
• C++: lang-cpp

Troubleshooting

cannot find entry symbol _start; not setting start address

Linker not happy because it expects a function with name _start to be present. This function is normally provided by some glue code for your program automatically, but it is not generated since we use special compiler flags.

Three ways to fix:

• Ignore it
• Add a mocked _start function that traps
• Add custom linker script to not get the warning

found an export without a relocation for a pointer to the metadata at <section #3+1>

Your linker flags are minced. Ensure that they contain -Wl,--emit-relocs.

failed to link "test.elf": truncated ecalli instruction

This was a but in polkatool, update it with cargo install --git https://github.com/koute/polkavm polkatool.