diff --git a/content/technical/2019/01/linux-conf-au-rust-epaper-badge.md b/content/technical/2019/01/linux-conf-au-rust-epaper-badge.md index 79712b1..6ae4b35 100644 --- a/content/technical/2019/01/linux-conf-au-rust-epaper-badge.md +++ b/content/technical/2019/01/linux-conf-au-rust-epaper-badge.md @@ -296,6 +296,10 @@ them something at the same time. All in all it was a fun project and excellent conference. If you're interested, [the Rust source for the badge is on GitHub][source]. +
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+ +Next Post: [Rebuilding My Personal Infrastructure With Alpine Linux and Docker](/technical/2019/02/alpine-linux-docker-infrastructure/) + [BADGEr]: https://wyolum.com/projects/badger/ [edunham-talk]: https://youtu.be/uCnnhMleoKA?t=530 [edunham]: http://edunham.net/ diff --git a/content/technical/2019/01/linux-conf-au-rust-epaper-badge.yaml b/content/technical/2019/01/linux-conf-au-rust-epaper-badge.yaml index 70cc82e..83d6705 100644 --- a/content/technical/2019/01/linux-conf-au-rust-epaper-badge.yaml +++ b/content/technical/2019/01/linux-conf-au-rust-epaper-badge.yaml @@ -4,7 +4,7 @@ extra: For linux.conf.au 2019 I built a digital conference badge using a Raspber kind: article section: technical created_at: 2019-01-27 11:00:00.000000000 +11:00 -updated_at: 2019-01-28T20:08:26+11:00 +updated_at: 2019-03-13T20:39:51+11:00 keywords: - rust - linux diff --git a/content/technical/2019/02/alpine-linux-docker-infrastructure.md b/content/technical/2019/02/alpine-linux-docker-infrastructure.md index a8fa7e3..87fbe97 100644 --- a/content/technical/2019/02/alpine-linux-docker-infrastructure.md +++ b/content/technical/2019/02/alpine-linux-docker-infrastructure.md @@ -124,7 +124,7 @@ decided early on that these weren't really for me: - A lot of them build the package from source instead of just installing the Alpine package. -- The Docker build was more complicated that I needed as it was trying to be +- The Docker build was more complicated than I needed as it was trying to be a generic image that anyone could pull and use. - I wasn't a huge fan of pulling random Docker images from the Internet, even if they were official images. @@ -384,6 +384,11 @@ TLS negotiations to one. Thanks for reading, I hope the bits didn't take too long to get from Australia to wherever you are. Happy computing! +
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+ +Previous Post: [My Rust Powered linux.conf.au e-Paper Badge](/technical/2019/01/linux-conf-au-rust-epaper-badge/) +Next Post: [A Coding Retreat and Getting Embedded Rust Running on a SensorTag](/technical/2019/03/sensortag-embedded-rust-coding-retreat/) + [acme.sh]: https://github.com/Neilpang/acme.sh [Alpine Linux]: https://alpinelinux.org/ [alpine-3.9.1]: https://alpinelinux.org/posts/Alpine-3.9.1-released.html diff --git a/content/technical/2019/02/alpine-linux-docker-infrastructure.yaml b/content/technical/2019/02/alpine-linux-docker-infrastructure.yaml index 32add5b..c66af16 100644 --- a/content/technical/2019/02/alpine-linux-docker-infrastructure.yaml +++ b/content/technical/2019/02/alpine-linux-docker-infrastructure.yaml @@ -4,7 +4,7 @@ extra: My story of replacing three servers, across two countries, running two op kind: article section: technical created_at: 2019-02-28 09:45:00.000000000 +11:00 -updated_at: 2019-03-02T14:09:11+11:00 +updated_at: 2019-03-13T20:37:45+11:00 keywords: - docker - linux diff --git a/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.md b/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.md new file mode 100644 index 0000000..2e1d977 --- /dev/null +++ b/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.md @@ -0,0 +1,241 @@ +This past long weekend some friends on I went on a coding retreat inspired by +John Carmack doing similar in 2018. During the weekend I worked on adding +support for the Texas Instruments SensorTag to the embedded Rust ecosystem. +This post is a summary of the weekend and what I was able to achieve code wise. + +Back in March 2018 [John Carmack posted about a week long coding +retreat][carmack] he went on to work on neural networks and [OpenBSD]. After +reading the post I quoted it to some friends and commented: + +> > I finally took another week-long programming retreat, where I could work in +> > hermit mode, away from the normal press of work. + +> > In the spirit of my retro theme, I had printed out several of Yann LeCun’s +> > old papers and was considering doing everything completely off line, as if +> > I was actually in a mountain cabin somewhere + +> I kind of love the idea of a week long code retreat in a cabin somewhere. + +One of my friends also liked the idea and actually made it happen! There was an +initial attempt in June 2018 but life got in the way so it was postponed. At +the start of the year he picked it up again and organised it for the Labour day +long weekend, which just passed. + +We rented an Airbnb in the Dandenong Ranges, 45 minutes from Melbourne. Six +people attended, two of which were from interstate. The setting was cozy, quiet +and picturesque. Our days involved coding and collaborating, shared meals, +and a walk or two around the surrounds. + +
+ Photo of a sunrise with trees and windmill visible +
The view from our accommodation one morning.
+
+ +After [linux.conf.au] I got inspired to set up some self-hosted home sensors +and automation. I did some research and picked up two [Texas Instruments +SensorTags][SensorTag] and a debugger add-on. It uses a [CC2650] +microcontroller with an ARM Cortex-M3 core and has support a number for low +power wireless standards, such as Bluetooth, ZigBee, and 6LoWPAN. The CC2650 +also has a low power 16-bit sensor controller that can be used to help achieve +years long battery life from a single CR2032 button cell. In addition to the +microcontroller the SensorTag also add a bunch of sensors, including: +temperature, humidity, barometer, accelerometer, gyroscope, and light. + +
+ Two SensorTags. One with it's rubberised case removed and debugger board attached +
Two SensorTags. One with it's rubberised case removed and + debugger board attached.
+
+ +My project for the weekend was to try to get some [Rust] code running on the +SensorTag. Rust has good support out of the box for targeting ARM Cortex +microcontrollers but there were no crates to make interacting with this +particular chip or board easy, so I set about building some. + +The first step was generating a basic crate to allow interacting with the chip +without needing to wrap everything in an `unsafe` block and poke at random +memory addresses. Fortunately [svd2rust] can automate this by converting System +View Description XML files (SVD) into a Rust crate. Unfortunately TI don't +publish SVD files for their devices. As luck would have it though, [M-Labs] +have found that TI do publish XML descriptions in format of their own called +DSLite. They have written a tool, [dslite2svd], that converts this to SVD, so +you can then use `svd2rust`. It took a while to get `dslite2svd` working and I +had to tweak to the tool to handle differences in the files I was processing, +but eventually I was able to generate a crate that compiled. + +Now that I had an API for the chip I turned to working out how to program and +debug the SensorTag with a very basic Rust program. I used the excellent +[embedded Rust Discovery guide][discovery] as a basis for the configuration, +tools, and process for getting code onto the SensorTag. Since this was a +different chip from a different manufacturer it took a long time to work out +which tools worked, how to configure them, what format binaries they wanted, +create a linker script, etc. A lot of trial and error was performed, along with +lots of searching online with less than perfect internet. However, by Sunday I +could program the device, debug code, and verify that my very basic program, +shown below, was running. + +```language-rust +fn main() -> ! { + let _y; + let x = 42; + _y = x; + + // infinite loop; just so we don't leave this stack frame + loop {} +} +``` + +The combination that worked for programming was: + +* `cargo build --target thumbv7m-none-eabi` +* Convert ELF to BIN using `cargo objcopy`, which is part of [cargo-binutils]: + `cargo objcopy --bin sensortag --target thumbv7m-none-eabi -- -O binary sensortag.bin` +* Program with [UniFlash]: + * Choose CC2650F128 and XDS1100 on the first screen + * Do a full erase the first time to reset CCFG, etc + * Load image (select the `.bin` file produced above) + +For debugging: + +* Build OpenOCD from git to get support for the chip and debugger (I used the + existing [AUR package][openocd-git]) +* Run OpenOCD: `openocd -f jtag/openocd.cfg` +* Use GDB to debug: `arm-none-eabi-gdb -x jtag/gdbinit -q target/thumbv7m-none-eabi/debug/sensortag` +* The usual `mon reset halt` in GDB upsets the debugger connection. I found + that `soft_reset_halt` was able to reset the target (although it complains + about being deprecated). + +_**Note:** Files in the `jtag` path above are in my +[sensortag repo](https://git.sr.ht/~wezm/sensortag/tree/master/jtag). +Trying to program through `openocd` failed with an error that the `vEraseFlash` +command failed. I'd be curious to know if anyone has got this working as I'd +very much like to ditch the huge 526.5 MiB UniFlash desktop-web-app dependency +in my workflow._ + +Now that I could get code to run on the SensorTag I set about trying to use the +generated chip support crate to flash one of the on board LEDs. I didn't +succeed in getting this working by the time the retreat came to an end, but +after I arrived home I was able to find the source of the hard faults I was +encountering and get the LED blinking! The key was that I needed to power up +the peripheral power domain and enable the GPIO clocks to be able to enable an +output GPIO. + +
+ +
It works!
+
+ +Below is the code that flashes the LED. It should be noted this code is +operating with very little abstraction and is using register and field names +that match the data sheet. Future work to implement the [embedded-hal] traits +for this controller would make it less verbose and less cryptic. + +```language-rust +#![deny(unsafe_code)] +#![no_main] +#![no_std] + +#[allow(unused_extern_crates)] // NOTE(allow) bug rust-lang/rust#53964 +extern crate panic_halt; // panic handler + +// SensorTag is using RGZ package. VQFN (RGZ) | 48 pins, 7×7 QFN + +use cc2650_hal as hal; +use cc2650f128; +use cortex_m_rt::entry; + +use hal::{ddi, delay::Delay, prelude::*}; + +pub fn init() -> (Delay, cc2650f128::Peripherals) { + let core_peripherals = cortex_m::Peripherals::take().unwrap(); + let device_peripherals = cc2650f128::Peripherals::take().unwrap(); + + let clocks = ddi::CFGR { + sysclk: Some(24_000_000), + } + .freeze(); + + let delay = Delay::new(core_peripherals.SYST, clocks); + + // LEDs are connected to DIO10 and DIO15 + // Configure GPIO pins for output, maximum strength + device_peripherals.IOC + .iocfg10 + .modify(|_r, w| w.port_id().gpio().ie().clear_bit().iostr().max()); + device_peripherals.IOC + .iocfg15 + .modify(|_r, w| w.port_id().gpio().ie().clear_bit().iostr().max()); + + // Enable the PERIPH power domain and wait for it to be powered up + device_peripherals.PRCM.pdctl0.modify(|_r, w| w.periph_on().set_bit()); + loop { + if device_peripherals.PRCM.pdstat0.read().periph_on().bit_is_set() { + break; + } + } + + // Enable the GPIO clock + device_peripherals.PRCM.gpioclkgr.write(|w| w.clk_en().set_bit()); + + // Load settings into CLKCTRL and wait for LOAD_DONE + device_peripherals.PRCM.clkloadctl.modify(|_r, w| w.load().set_bit()); + loop { + if device_peripherals.PRCM.clkloadctl.read().load_done().bit_is_set() { + break; + } + } + + // Enable outputs + device_peripherals.GPIO + .doe31_0 + .modify(|_r, w| w.dio10().set_bit().dio15().set_bit()); + + (delay, device_peripherals) +} + +#[entry] +fn entry() -> ! { + let (mut delay, periphs) = init(); + let half_period = 500_u16; + + loop { + // Turn LED on and wait half a second + periphs.GPIO.dout11_8.modify(|_r, w| w.dio10().set_bit()); + delay.delay_ms(half_period); + + // Turn LED off and wait half a second + periphs.GPIO.dout11_8.modify(|_r, w| w.dio10().clear_bit()); + delay.delay_ms(half_period); + } +} +``` + +The rest of the code is up on [Sourcehut]. It's all in a pretty rough state at +the moment. I plan to tidy it up over the coming weeks and eventually publish +the crates. If you're curious to see it now though, the repos are: + +* [cc2650f128](https://git.sr.ht/~wezm/cc2650f128) -- chip support crate + generated by `dslite2svd` and `svd2rust`. +* [cc26x0-hal](https://git.sr.ht/~wezm/cc26x0-hal) (see `wip` branch, currently + very rough). +* [sensortag](https://git.sr.ht/~wezm/sensortag) -- LED flashing code. I hope + to turn this into a board support crate eventually. + +Overall the coding retreat was a great success and we hope to do another one +next year. + +[cargo-binutils]: https://crates.io/crates/cargo-binutils +[carmack]: https://www.facebook.com/permalink.php?story_fbid=2110408722526967&id=100006735798590 +[CC2650]: http://www.ti.com/product/CC2650 +[discovery]: https://rust-embedded.github.io/discovery/ +[dslite2svd]: https://github.com/m-labs/dslite2svd +[embedded-hal]: https://crates.io/crates/embedded-hal +[linux.conf.au]: /technical/2019/01/linux-conf-au-rust-epaper-badge/ +[M-Labs]: https://github.com/m-labs +[OpenBSD]: https://www.openbsd.org/ +[openocd-git]: https://aur.archlinux.org/packages/openocd-git/ +[Rust]: https://www.rust-lang.org/ +[SensorTag]: http://www.ti.com/tool/cc2650stk +[Sourcehut]: https://sourcehut.org/ +[svd2rust]: https://github.com/rust-embedded/svd2rust +[UniFlash]: http://www.ti.com/tool/uniflash diff --git a/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.yaml b/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.yaml new file mode 100644 index 0000000..177fe61 --- /dev/null +++ b/content/technical/2019/03/sensortag-embedded-rust-coding-retreat.yaml @@ -0,0 +1,14 @@ +--- +title: A Coding Retreat and Getting Embedded Rust Running on a SensorTag +extra: I attended a small coding retreat with some friends and worked on running Rust code on a CC2650 based TI SensorTag. +kind: article +section: technical +created_at: 2019-03-12 19:45:00.000000000 +11:00 +#updated_at: 2019-03-02T14:09:11+11:00 +keywords: + - rust + - embedded + - sensortag + - arm + - microcontroller +short_url: diff --git a/output/images/2019/coding-retreat-sunrise.jpg b/output/images/2019/coding-retreat-sunrise.jpg new file mode 100644 index 0000000..c009392 Binary files /dev/null and b/output/images/2019/coding-retreat-sunrise.jpg differ diff --git a/output/images/2019/sensortag-flashing-led.m4v b/output/images/2019/sensortag-flashing-led.m4v new file mode 100644 index 0000000..291f533 Binary files /dev/null and b/output/images/2019/sensortag-flashing-led.m4v differ diff --git a/output/images/2019/sensortag.jpg b/output/images/2019/sensortag.jpg new file mode 100644 index 0000000..6c0f90a Binary files /dev/null and b/output/images/2019/sensortag.jpg differ