josemirm/msp430-quickstart

Template to develop bare metal applications for MSP430 microcontrollers

msp430-quickstart

A template for building applications for TI MSP430 microcontrollers.

This project is developed and maintained by the MSP430 team.

Dependencies

• Rust nightly-2019-03-27 or a newer toolchain. Only nightly compilers work for now.

  You can set up a nightly compiler as the default compiler using rustup default nightly. Alternatively, you can set up overrides on a project basis using rustup override set --path /path/to/crate nightly-YYYY-MM-DD

• The cargo generate subcommand (Installation instructions).

• TI's MSP430 GCC Compiler, version 8.3.0 or greater. msp430-elf-gcc should be visible on the path.

• svd2rust, commit 783fbd0 or newer.

• msp430_svd, commit e1eb730 or newer. Cloning the repo and following the directions in README.md is sufficient.

Using this template

0. Before instantiating a project, you need to know some characteristics about your specific MSP430 device that will be used to fill in the template. In particular:

   • What is the exact part number of your device? Which MSP430 family does your part belong to?

   • Does your part have an already-existing peripheral access crate (PAC)?

   • How much flash memory, RAM, and how many interrupt vectors does your device have?

   • Where does flash memory, RAM, and interrupt vectors begin in the address space?

   msp430g2553 is used for the examples in this crate. Answering the first question above:

   • msp430g2553 belongs to the MSP430x2xx family.

   The linked family manual and datasheet can be used to answer the remaining questions:

   • The msp430g2553 PAC exists already and can be found on crates.io.

   • msp430g2553 has 16kB of flash memory, 512 bytes of RAM, and 16 vectors.

   • Flash memory begins at address 0xC000. RAM begins at address 0x0200. The interrupt vectors begin at 0xFFE0.

1. If your particular device does not have a PAC crate, you will need to generate one using svd2rust and possibly publish the crate to https://crates.io. To generate an SVD file, follow the directions in the msp430_svd README.md for your device.

   In some cases like msp430fr2355, TI's linker files are not consistent with datasheets on where interrupt vectors begin and how many interrupt vectors there are for a given device. In case of a conflict, examine the linker script to determine where to start the VECTORS section in memory.x. Copies of many linker scripts are kept in the msp430_svd repository.

2. Instantiate the template.

   $ cargo generate --git https://github.com/rust-embedded/msp430-quickstart
   Project Name: app
   Creating project called `app`...
   Done! New project created /tmp/app
   
   $ cd app

3. If not targeting msp430g2553, replace the PAC entry for msp430g2553 in Cargo.toml with that of your device, e.g.:

   # [dependencies.msp430g2553]
   # version = "0.2.0"
   # features = ["rt"]
   [dependencies.msp430fr2355]
   version = "0.4.0"
   features = ["rt"]

4. Populate the memory.x file with address space layout information of your device. Note: As mentioned above, in case of a conflict between the datasheet and linker script on where interrupt vectors begin, use the linker script!

   $ cat memory.x
   MEMORY
   {
     /* These values are correct for the msp430g2553 device. You will need to
        modify these values if using a different device. Room must be reserved
        for interrupt vectors plus reset vector and the end of the first 64kB
        of address space. */
     RAM : ORIGIN = 0x0200, LENGTH = 0x0200
     ROM : ORIGIN = 0xC000, LENGTH = 0x3FE0
     VECTORS : ORIGIN = 0xFFE0, LENGTH = 0x20
   }

5. Build the template application or one of the examples. If building timer-oncecell, don't forget to uncomment the once_cell dependency in Cargo.toml! Some examples (such as timer) may not compile due to size constraints when building using the dev profile (the default).

   $ cargo build -Zbuild-std=core
   $ cargo build -Zbuild-std=core --examples

6. Once you have an ELF binary built, flash it to your microcontroller. Use mspdebug to launch a debug session and msp430-elf-gdb with the linked gdb script. For the msp430g2553 and the MSP-EXP430G2 launchpad board this looks like the following:

   In one terminal session

   $ mspdebug -C mspdebug.cfg rf2500

   In another terminal session

   $ msp430-elf-gdb -x mspdebug.gdb target/msp430-none-elf/debug/app

   This will flash your Rust code to the microcontroller and open a gdb debugging session to step through it.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.