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## D7018E - Special Studies in Embedded Systems

Disclaimer: This document is in beta state!!!!! Just to give a hint how the course will look like.

The course will be given as a self study course with a set of introductional seminars and accompanying mandatory assignments, followed by a larger assignment (project). The project can be carried out individually or in groups depending on size. Grading will be individual, based on agreed requirements between the student and the teacher, showing understanding and abilities regarding:

The course will be given as a self study course with a set of introduction seminars and accompanying mandatory assignments, followed by a larger assignment (project). The project can be carried out individually or in groups depending on size. Grading will be individual, based on agreed requirements between the student and the teacher, showing understanding and abilities regarding:

1. The Rust ecosystem. [ecosystem](doc/Ecosystem.md)

8. Building and debugging embedded code in Rust

    Hardware abstractions using svd2rust (autogenerated from vendor-provided SVD specifications). Compiling using xargo. Setting up openocd and gdb.

    Hardware abstractions using svd2rust (auto-generated from vendor-provided SVD specifications). Compiling using xargo. Setting up openocd and gdb.

9. Pre-processing

    Custom build.rs build scripts, and the RTFM Concurrent Reactive Component model.

There will be two presentation rounds (at end of LP2 and LP3). Students taking (too many other) courses during LP2 may choose to present their project at end of LP3 (instead of LP2). Presentations will be oral, where the student(s), will present and demonstrate their work.

Projects should be related to embedded programming, either on the target side (some application using the RTFM-core or CRC model), or on the host side, communicating with an embedded target running Rust RTFM. E.g., two groups can work together with building a system, e.g., with back-end processing of data collected by the embedded system, or by providing a front-end to the embedded system. Alternatively, host side project could relate the development of the RTFM-core/ RTFM-CRC frameworks or related tools (e.g. LLWM-KLEE as a backend for analysis of Rust code).

Projects should be related to embedded programming, either on the target side (some application using the RTFM-core or CRC model), or on the host side, communicating with an embedded target running Rust RTFM. E.g., two groups can work together with building a system, e.g., with back-end processing of data collected by the embedded system, or by providing a front-end to the embedded system. Alternatively, host side project could relate the development of the RTFM-core/ RTFM-CRC frameworks or related tools (e.g. LLVM-KLEE as a back-end for analysis of Rust code).

## Resources

Students will carry out the assignments on their personal laptops (in case you don't have a working laptop we will try to lend you one). Tools used are available for Linux and OSX, but with a bit of trickery windows based installations should be possible (but you are on your own here). In case you don't run OSX/Linux native, virtual box or VMware is possible, though debugging of target MCUs are feasible it is a bit more tricky.

    * Topic [Memory](doc/Memory.md)

        In-depth discussion of underlying theory, linear types (relation to functional programming). The *Affine* type system of Rust, requirements on the programmer, and guarantees offered by the compiler. Lifetimes, of stack allocated and global variables. Relation to C++ `unique pointers`.

    * Assignment

    * Assignment 3

        a. Recall the D0013E course lab2/4, where you decrypted a message in assembler (lab2) and C (lab 4). Now, let's re-implement the lab in Rust (base your development on group number [1's](http://www.sm.luth.se/csee/courses/smd/D0013E/labs/lab1underlag/grupp_01.lab1_underlag.s ) lab assignment).

        The `seed`, `abc`,`coded` and `plain` should be stack allocated. The decoded string should be printed when decryption is finished.

        b. Make the `seed`, `abc`,`coded` and `plain` static (heap) allocated (i.e., as global varibles). Accessing those will require some `unsafe` code. (Keep the unsafe blocks as local as possible.)

        b. Make the `seed`, `abc`,`coded` and `plain` static (heap) allocated (i.e., as global variables). Accessing those will require some `unsafe` code. (Keep the unsafe blocks as local as possible.)

        c. Safety analysis. Provoke the implementation, by omitting the `'\0'` (null termination). Observe the result and motivate the behavior in terms of your understanding of the Rust memory model. Under which circumstances do you consider 3a and 3b to have same/different memory safety.

        * `blue-pill` and `nucleo` board support crates

        * Building and debugging your first application.

    * Assignment

    * Assignment 4

        a. Backport assignment `3b` to your chosen target. Use semihosting in order to `write` the resulting string to the host. You may need to use `--release` for decoding the long (`coded`) message, as being deeply recursive unoptimized code may run out of stack memory.

        a. Backport assignment `3b` to your chosen target. Use semi-hosting in order to `write` the resulting string to the host. You may need to use `--release` for decoding the long (`coded`) message, as being deeply recursive unoptimized code may run out of stack memory.

        b. Discuss from a memory safety perspective the outcome.

        c. Compare for the short message (`abc`), the number of cycles required for `decode` in debug (standard) vs. `--release`. As a comparison my straightforword C implementation took 2200 cycles in best optimized mode using `gcc` (-o3), while my (translation) to Rust code took 1780 cycles (--release). (Both executed on a bluepill board at 8MHz without (flash) memory wait states).

        c. Compare for the short message (`abc`), the number of cycles required for `decode` in debug (standard) vs. `--release`. As a comparison my straightforward C implementation took 2200 cycles in best optimized mode using `gcc` (-o3), while my (translation) to Rust code took 1780 cycles (--release). (Both executed on a bluepill board at 8MHz without (flash) memory wait states).

        Make a new git for your embedded development. Make three branches (`3a, 3b, 3c`) with updated documentation according to the above.

        Make a new git for your embedded development. Make three branches (`4a, 4b, 4c`) with updated documentation according to the above.

5. Advanced Rust Concepts

    * Preparation

        Be prepared to present the progress on assignment 3.

        Be prepared to present the progress on assignment 4.

    * Topic

        Advanced Rust features, trait system and closures.

        * [13 - Functional Language Features in Rust](https://doc.rust-lang.org/book/second-edition/ch13-00-functional-features.html).

    * Assignment

        Continue working on assignment 3.

        Continue working on assignment 4.

6. Memory Safe Concurrency

    * Preparation

        * Finish lab 3 and be prepared to show your solution.

        * Finish assignment 4 and be prepared to show your solution.

    * Topic

        * UnsafeCell, and synchronization in the RTFM model.

        * [cortex-m-rtfm](https://github.com/japaric/cortex-m-rtfm) The RTFM-core (task and resource model) in Rust for the Cortex-M family

        * [svd2rust](https://github.com/japaric/svd2rust) Generating

    * Assignment 4

    * Assignment 5

        Implement a simple system with 3 tasks

        * A periodic task executing each Xms (free of accumulated drift, and with minimal jitter), that blinks the onboard LED, and

        * A periodic task executing each Xms (free of accumulated drift, and with minimal jitter), that blinks the on-board LED, and

        * A USART task receiving commands (pause, start, period 1-1000ms), received commands should be parsed and corresponding responses generated and sent over the USART. (Come up with a nice and simple user interface.)

        * A a logging task, run each second (period 1s), that prints statistics of CPU usage over the ITM port

        * Idle should gather statics on sleep/up time, (there is a sleep counter in the cortex core) 

        * Use shared resources (data structures) to ensure race free execution

        You may use the core systic timer (relative) and the dwt cycle counter (absoulte) in combination to achieve drift free timing. Alternative you look inte the stm32f4xx timer peripheral. There is a support crate for the [STM32F3DISCOVERY](https://github.com/japaric/f3) board. Periherals are similar so you may "borrow" code from there.

        You may use the core systic timer (relative) and the dwt cycle counter (absolute) in combination to achieve drift free timing. Alternative you look into the stm32f4xx timer peripheral. There is a support crate for the [STM32F3DISCOVERY](https://github.com/japaric/f3) board. Peripherals are similar so you may "borrow" code from there.

        Make a new git with the development and documentation.

        Optional:

        Find a way to measure the power consumpion. A possible solution is to power the board externally and use a power cube with current measuring capability. Alternative use an external power source with known charge (e.g., a "capacitor"), and measure the discharge time (start and residue charge at brown-out voltage), at least a precise relative measure is possible to obtain. 

        Find a way to measure the power consumption. A possible solution is to power the board externally and use a power cube with current measuring capability. Alternative use an external power source with known charge (e.g., a "capacitor"), and measure the discharge time (start and residue charge at brown-out voltage), at least a precise relative measure is possible to obtain. 

        Operation without being connected to the USB port: in this case the serial IO and ITM needs to be connected externally (e.g., using some ftdi serial-USB).

        Super optional:

        Try to minimize power consumption while maintaining desired operatotion. Lowering supply voltage and using aggressive power modes of the processor might be applied. (Not sure how USART/ITM communication can be made possible at sub 3.3v voltages. Also you have to make sure not to source the board over the communication interfaces.)

        Try to minimize power consumption while maintaining desired operation. Lowering supply voltage and using aggressive power modes of the processor might be applied. (Not sure how USART/ITM communication can be made possible at sub 3.3v voltages. Also you have to make sure not to source the board over the communication interfaces.)

7. Macros and Projects (Monday Nov. 20th)

    * Preparation 

        Be prepared to present the progress on assignment 4.

        Be prepared to present the progress on assignment 5.

    * Topic

        - We will cover the implementation of the RTFM-core crate.

        - We will cover the implementation of the rtfm-core and the cortex-m-rtfm crates. For details see [RTFM](doc/RTFM.md).

          Special focus to `macro_rules` and `procedural macros`.

8. Wrap-up (Monday Dec. 4th)

    * Preparation

        * Be prepared to present assignment 4.

        * Be prepared to present assignment 5.

        * Be prepared to present your project, 10 minutes per project.

        * A good idea is to prepare a git for the project with a `README.md` and use that as supporting material for your presentation. Its advicable to have a section (or in a doc sub folder) where you collect references to the material you will use, i.e., links to data sheets, links to other related crates and projects of importance to your project. 

        This type of reference section will be largely helpful to both you (during the project and afterwards maintaining it, but also to other users and people interested in your work). Moreover, from a "course" perspective it shows that you have done the necessary background studies BEFORE you "hack away". Of corse this will be a living document, updated throughout the project, but its a very good thing to start out NOW, then it can be used for your 10 minutes of fame!

The [rustup](https://www.rustup.rs/), tool manager allows you to manage multiple tool chain installations. Rust is distributed in three channels (`stable`, `beta` and `nightly`). You may set the default toolchain:

```

rustup default nightly-2017-10-22-x86_64-unknown-linux-gnu 

rustup default nightly-2018-01-10-x86_64-unknown-linux-gnu 

```

and get information on the status of `rustup`

```

rustup show

```

Nightly tool chains allow for the development of libraries and applications including `unsafe` code using features not available on the `stable channel` (which will be necessary for the later exercises). For some tools to work (`rls/rustfmt`), you need to install additional components. For this to work, you should use a nightly toolchain for which all tools and components work (currently `nightly-2017-10-30` is the latest). Here is an example:

Nightly tool chains allow for the development of libraries and applications including `unsafe` code using features not available on the `stable channel` (which will be necessary for the later exercises). For some tools to work (`rls/rustfmt`), you need to install additional components. For this to work, you should use a nightly toolchain for which all tools and components work (currently `nightly-2018-01-10` is the latest). Here is an example:

```

rustup default nightly-2017-10-30

rustup default nightly-2018-01-10

rustup component add rls-preview

rustup component add rust-analysis

rustup component add rust-src

See [rls](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust) for installing the RLS extension.

You will need to pin the specific toolchain version used, by setting the `"rust-client.channel": "nightly-2017-10-30"` in your `vscode` *user* settings (this will be stored in a file `~/.config/Code/User/settings.json` and used for all your `vscode` projects. Settings may be set individually for each *workspace*, overriding the defaults. Regarding the  `"rust-client.channel"` setting, a *workspace* setting would force the specific version (overriding the default), and may not work when the code is distributed (as other developers may be on other toolchains).

You will need to pin the specific toolchain version used, by setting the `"rust-client.channel": "nightly-2018-01-10"` in your `vscode` *user* settings (this will be stored in a file `~/.config/Code/User/settings.json` and used for all your `vscode` projects. Settings may be set individually for each *workspace*, overriding the defaults. Regarding the  `"rust-client.channel"` setting, a *workspace* setting would force the specific version (overriding the default), and may not work when the code is distributed (as other developers may be on other toolchains).

For RLS to work, `vscode` need a path to the `rls-preview` library (using the environment variable `LD_LIBRARY_PATH` (Linux), `DYLD_LIBRARY_PATH` (OSX ?)). 

```

# Nucleo 64

A collection of documentation, tricks and tips regarding the ST Nucleo 64 development kit.

# STM32 Nucleo-64 Board

A collection of documentation, tricks and tips regarding the STM32 Nucleo-64 Board (development kit).

We will mainly cover the `stm32f401re` and `stm32f411re` as these models.

We will mainly cover the `stm32f401re` and `stm32f411re` as these models (main difference is the higher maximum clock frequency of the `stm32f411re`).

---

## Stlink inteface

The nucleo-64 platform has an onboard `stlink-v2.1` SWD interface (programmer) supported by `openocd`. By default the programmer is connected to the target (`stm32f401re` or similar). 

---

### Programming external targets

You may use the board as a programmer (connector `CN4` SWD), in that case you should remove the `CN3` jumpers, and optionally desolder `SB15` (SWO) and `SB12` (NRST). See board documentation for details. 

## Links

* [Nucleo-64 board](http://www.st.com/content/ccc/resource/technical/document/user_manual/98/2e/fa/4b/e0/82/43/b7/DM00105823.pdf/files/DM00105823.pdf/jcr:content/translations/en.DM00105823.pdf) 

    Board documentation.

* [Firmware Upgrade](http://www.st.com/en/development-tools/stsw-link007.html)

    Standalone java program.

# Clocking

* [Note on Overclocking](https://stm32f4-discovery.net/2014/11/overclock-stm32f4-device-up-to-250mhz/)

In order to be officially enrolled for the course each student need to write (and submit) an individual course plan including grading goals and assessments based on this document. 

Assignments are mandatory (as detailed in the README.md). 

- Each student should for each assigment 2,3,4 comment (make an `issue` and/or `pull request` to one other `git`). Comments should be meaningful and constructive. For the assigment 2, 3, 4 you should comment on different groups. Strive to spread comments so that each group will get at least one comment for each assignment.

- Each student should for each assigment 2, .., 5 comment (make an `issue` and/or `pull request` to one other `git`). Comments should be meaningful and constructive. For the assigment 2, .., 5 you should comment on different groups. Strive to spread comments so that each group will get at least one comment for each assignment.

- Each student/group should attend `issues`/`pull request`

Projects should aim to further cover the learning goals as stated in the README.md. 

# Suggested projects

---

## Printing device (William)

- Rotating stick with LEDs at the end of the stick that can "print" text by switching the LEDs on and off with the right timings.

---

## Seer (Nils)

Symbolic execution engine for MIR internal format

- Arch Linux

``` console

$ sudo pacman -Sy arm-none-eabi-{binutils,gdb} openocd

$ sudo pacman -Sy arm-none-eabi-{binutils,gdb}

```

OpenOCD is in AUR:

```

$ yaourt -S openocd

```

For hardware-association and pre-packaged UDEV-rules also install:

Now pick from the menu: `Tasks > Configure Default Build Task...` and pick `xargo build`.

Now you should be able to build your project by picking `Tasks > Run Build Task...` from the menu or

by hitting the shorcut `Ctrl + Shift + B`.

by hitting the shortcut `Ctrl + Shift + B`.

![Build task](/assets/vscode-build.png)