| Minos Galanakis | 2c824b4 | 2025-03-20 09:28:45 +0000 | [diff] [blame^] | 1 | # psasim |
| 2 | |
| 3 | This tool simulates a PSA Firmware Framework implementation. |
| 4 | It allows you to develop secure partitions and their clients on a desktop computer. |
| 5 | It should be able to run on all systems that support POSIX and System V IPC: |
| 6 | e.g. macOS, Linux, FreeBSD, and perhaps Windows 10 WSL2. |
| 7 | |
| 8 | Please note that the code in this directory is maintained by the Mbed TLS / PSA Crypto project solely for the purpose of testing the use of Mbed TLS with client/service separation. We do not recommend using this code for any other purpose. In particular: |
| 9 | |
| 10 | * This simulator is not intended to pass or demonstrate compliance. |
| 11 | * This code is only intended for simulation and does not have any security goals. It does not isolate services from clients. |
| 12 | |
| 13 | ## Building |
| 14 | |
| 15 | To build and run the test program make sure you have `make`, `python` and a |
| 16 | C compiler installed and then enter the following commands: |
| 17 | |
| 18 | ```sh |
| 19 | make install |
| 20 | make run |
| 21 | ``` |
| 22 | |
| 23 | On Linux you may need to run `ldconfig` to ensure the library is properly installed. |
| 24 | |
| 25 | An example pair of programs is included in the `test` directory. |
| 26 | |
| 27 | ## Features |
| 28 | |
| 29 | The implemented API is intended to be compliant with PSA-FF 1.0.0 with the exception of a couple of things that are a work in progress: |
| 30 | |
| 31 | * `psa_notify` support |
| 32 | * "strict" policy in manifest |
| 33 | |
| 34 | The only supported "interrupts" are POSIX signals, which act |
| 35 | as a "virtual interrupt". |
| 36 | |
| 37 | The standard PSA RoT APIs are not included (e.g. cryptography, attestation, lifecycle etc). |
| 38 | |
| 39 | ## Design |
| 40 | |
| 41 | The code is designed to be readable rather than fast or secure. |
| 42 | In this implementation only one message is delivered to a |
| 43 | RoT service at a time. |
| 44 | The code is not thread-safe. |
| 45 | |
| 46 | To debug the simulator enable the debug flag: |
| 47 | |
| 48 | ```sh |
| 49 | make DEBUG=1 install |
| 50 | ``` |
| 51 | |
| 52 | ## Unsupported features |
| 53 | |
| 54 | Because this is a simulator there are a few things that |
| 55 | can't be reasonably emulated: |
| 56 | |
| 57 | * Manifest MMIO regions are unsupported |
| 58 | * Manifest priority field is ignored |
| 59 | * Partition IDs are in fact POSIX `pid_t`, which are only assigned at runtime, |
| 60 | making it infeasible to populate pid.h with correct values. |