nrf52840dk_lib/

lib.rs

// Licensed under the Apache License, Version 2.0 or the MIT License.
// SPDX-License-Identifier: Apache-2.0 OR MIT
// Copyright Tock Contributors 2022.

//! Tock kernel for the Nordic Semiconductor nRF52840 development kit (DK).
//!
//! It is based on nRF52840 SoC (Cortex M4 core with a BLE transceiver) with
//! many exported I/O and peripherals.
//!
//! Pin Configuration
//! -------------------
//!
//! ### `GPIO`
//!
//! | #  | Pin   | Ix | Header | Arduino |
//! |----|-------|----|--------|---------|
//! | 0  | P1.01 | 33 | P3 1   | D0      |
//! | 1  | P1.02 | 34 | P3 2   | D1      |
//! | 2  | P1.03 | 35 | P3 3   | D2      |
//! | 3  | P1.04 | 36 | P3 4   | D3      |
//! | 4  | P1.05 | 37 | P3 5   | D4      |
//! | 5  | P1.06 | 38 | P3 6   | D5      |
//! | 6  | P1.07 | 39 | P3 7   | D6      |
//! | 7  | P1.08 | 40 | P3 8   | D7      |
//! | 8  | P1.10 | 42 | P4 1   | D8      |
//! | 9  | P1.11 | 43 | P4 2   | D9      |
//! | 10 | P1.12 | 44 | P4 3   | D10     |
//! | 11 | P1.13 | 45 | P4 4   | D11     |
//! | 12 | P1.14 | 46 | P4 5   | D12     |
//! | 13 | P1.15 | 47 | P4 6   | D13     |
//! | 14 | P0.26 | 26 | P4 9   | D14     |
//! | 15 | P0.27 | 27 | P4 10  | D15     |
//!
//! ### `GPIO` / Analog Inputs
//!
//! | #  | Pin        | Header | Arduino |
//! |----|------------|--------|---------|
//! | 16 | P0.03 AIN1 | P2 1   | A0      |
//! | 17 | P0.04 AIN2 | P2 2   | A1      |
//! | 18 | P0.28 AIN4 | P2 3   | A2      |
//! | 19 | P0.29 AIN5 | P2 4   | A3      |
//! | 20 | P0.30 AIN6 | P2 5   | A4      |
//! | 21 | P0.31 AIN7 | P2 6   | A5      |
//! | 22 | P0.02 AIN0 | P4 8   | AVDD    |
//!
//! ### Onboard Functions
//!
//! | Pin   | Header | Function |
//! |-------|--------|----------|
//! | P0.05 | P6 3   | UART RTS |
//! | P0.06 | P6 4   | UART TXD |
//! | P0.07 | P6 5   | UART CTS |
//! | P0.08 | P6 6   | UART RXT |
//! | P0.11 | P24 1  | Button 1 |
//! | P0.12 | P24 2  | Button 2 |
//! | P0.13 | P24 3  | LED 1    |
//! | P0.14 | P24 4  | LED 2    |
//! | P0.15 | P24 5  | LED 3    |
//! | P0.16 | P24 6  | LED 4    |
//! | P0.18 | P24 8  | Reset    |
//! | P0.19 | P24 9  | SPI CLK  |
//! | P0.20 | P24 10 | SPI MOSI |
//! | P0.21 | P24 11 | SPI MISO |
//! | P0.22 | P24 12 | SPI CS   |
//! | P0.24 | P24 14 | Button 3 |
//! | P0.25 | P24 15 | Button 4 |
//! | P0.26 | P24 16 | I2C SDA  |
//! | P0.27 | P24 17 | I2C SCL  |

#![no_std]
#![deny(missing_docs)]

use core::ptr::addr_of;

use capsules_core::virtualizers::virtual_alarm::{MuxAlarm, VirtualMuxAlarm};
use capsules_extra::net::ieee802154::MacAddress;
use capsules_extra::net::ipv6::ip_utils::IPAddr;
use kernel::component::Component;
use kernel::hil::led::LedLow;
use kernel::hil::time::Counter;
#[allow(unused_imports)]
use kernel::hil::usb::Client;
use kernel::platform::{KernelResources, SyscallDriverLookup};
use kernel::process::ProcessArray;
use kernel::scheduler::round_robin::RoundRobinSched;
#[allow(unused_imports)]
use kernel::{capabilities, create_capability, debug, debug_gpio, debug_verbose, static_init};
use nrf52840::gpio::Pin;
use nrf52840::interrupt_service::Nrf52840DefaultPeripherals;
use nrf52_components::{UartChannel, UartPins};

// The nRF52840DK LEDs (see back of board)
const LED1_PIN: Pin = Pin::P0_13;
const LED2_PIN: Pin = Pin::P0_14;
const LED3_PIN: Pin = Pin::P0_15;
const LED4_PIN: Pin = Pin::P0_16;

// The nRF52840DK buttons (see back of board)
const BUTTON1_PIN: Pin = Pin::P0_11;
const BUTTON2_PIN: Pin = Pin::P0_12;
const BUTTON3_PIN: Pin = Pin::P0_24;
const BUTTON4_PIN: Pin = Pin::P0_25;
const BUTTON_RST_PIN: Pin = Pin::P0_18;

const UART_RTS: Option<Pin> = Some(Pin::P0_05);
const UART_TXD: Pin = Pin::P0_06;
const UART_CTS: Option<Pin> = Some(Pin::P0_07);
const UART_RXD: Pin = Pin::P0_08;

const SPI_MOSI: Pin = Pin::P0_20;
const SPI_MISO: Pin = Pin::P0_21;
const SPI_CLK: Pin = Pin::P0_19;
const SPI_CS: Pin = Pin::P0_22;

const SPI_MX25R6435F_CHIP_SELECT: Pin = Pin::P0_17;
const SPI_MX25R6435F_WRITE_PROTECT_PIN: Pin = Pin::P0_22;
const SPI_MX25R6435F_HOLD_PIN: Pin = Pin::P0_23;

/// I2C pins
const I2C_SDA_PIN: Pin = Pin::P0_26;
const I2C_SCL_PIN: Pin = Pin::P0_27;

// Constants related to the configuration of the 15.4 network stack
const PAN_ID: u16 = 0xABCD;
const DST_MAC_ADDR: capsules_extra::net::ieee802154::MacAddress =
    capsules_extra::net::ieee802154::MacAddress::Short(49138);
const DEFAULT_CTX_PREFIX_LEN: u8 = 8; //Length of context for 6LoWPAN compression
const DEFAULT_CTX_PREFIX: [u8; 16] = [0x0_u8; 16]; //Context for 6LoWPAN Compression

/// Debug Writer
pub mod io;

// Whether to use UART debugging or Segger RTT (USB) debugging.
// - Set to false to use UART.
// - Set to true to use Segger RTT over USB.
const USB_DEBUGGING: bool = false;

/// This platform's chip type:
pub type Chip = nrf52840::chip::NRF52<'static, Nrf52840DefaultPeripherals<'static>>;

/// Number of concurrent processes this platform supports.
pub const NUM_PROCS: usize = 8;

/// Static variables used by io.rs.
static mut PROCESSES: Option<&'static ProcessArray<NUM_PROCS>> = None;
static mut CHIP: Option<&'static nrf52840::chip::NRF52<Nrf52840DefaultPeripherals>> = None;
static mut PROCESS_PRINTER: Option<&'static capsules_system::process_printer::ProcessPrinterText> =
    None;

kernel::stack_size! {0x2000}

//------------------------------------------------------------------------------
// SYSCALL DRIVER TYPE DEFINITIONS
//------------------------------------------------------------------------------

type AlarmDriver = components::alarm::AlarmDriverComponentType<nrf52840::rtc::Rtc<'static>>;
type RngDriver = components::rng::RngComponentType<nrf52840::trng::Trng<'static>>;

// TicKV
type Mx25r6435f = components::mx25r6435f::Mx25r6435fComponentType<
    nrf52840::spi::SPIM<'static>,
    nrf52840::gpio::GPIOPin<'static>,
    nrf52840::rtc::Rtc<'static>,
>;
const TICKV_PAGE_SIZE: usize =
    core::mem::size_of::<<Mx25r6435f as kernel::hil::flash::Flash>::Page>();
type Siphasher24 = components::siphash::Siphasher24ComponentType;
type TicKVDedicatedFlash =
    components::tickv::TicKVDedicatedFlashComponentType<Mx25r6435f, Siphasher24, TICKV_PAGE_SIZE>;
type TicKVKVStore = components::kv::TicKVKVStoreComponentType<
    TicKVDedicatedFlash,
    capsules_extra::tickv::TicKVKeyType,
>;
type KVStorePermissions = components::kv::KVStorePermissionsComponentType<TicKVKVStore>;
type VirtualKVPermissions = components::kv::VirtualKVPermissionsComponentType<KVStorePermissions>;
type KVDriver = components::kv::KVDriverComponentType<VirtualKVPermissions>;

// Temperature
type TemperatureDriver =
    components::temperature::TemperatureComponentType<nrf52840::temperature::Temp<'static>>;

// IEEE 802.15.4
type Ieee802154MacDevice = components::ieee802154::Ieee802154ComponentMacDeviceType<
    nrf52840::ieee802154_radio::Radio<'static>,
    nrf52840::aes::AesECB<'static>,
>;
/// Userspace 802.15.4 driver with in-kernel packet framing and MAC layer.
pub type Ieee802154Driver = components::ieee802154::Ieee802154ComponentType<
    nrf52840::ieee802154_radio::Radio<'static>,
    nrf52840::aes::AesECB<'static>,
>;

// EUI64
/// Userspace EUI64 driver.
pub type Eui64Driver = components::eui64::Eui64ComponentType;

/// Supported drivers by the platform
pub struct Platform {
    ble_radio: &'static capsules_extra::ble_advertising_driver::BLE<
        'static,
        nrf52840::ble_radio::Radio<'static>,
        VirtualMuxAlarm<'static, nrf52840::rtc::Rtc<'static>>,
    >,
    button: &'static capsules_core::button::Button<'static, nrf52840::gpio::GPIOPin<'static>>,
    pconsole: &'static capsules_core::process_console::ProcessConsole<
        'static,
        { capsules_core::process_console::DEFAULT_COMMAND_HISTORY_LEN },
        VirtualMuxAlarm<'static, nrf52840::rtc::Rtc<'static>>,
        components::process_console::Capability,
    >,
    console: &'static capsules_core::console::Console<'static>,
    gpio: &'static capsules_core::gpio::GPIO<'static, nrf52840::gpio::GPIOPin<'static>>,
    led: &'static capsules_core::led::LedDriver<
        'static,
        kernel::hil::led::LedLow<'static, nrf52840::gpio::GPIOPin<'static>>,
        4,
    >,
    rng: &'static RngDriver,
    adc: &'static capsules_core::adc::AdcDedicated<'static, nrf52840::adc::Adc<'static>>,
    temp: &'static TemperatureDriver,
    /// The IPC driver.
    pub ipc: kernel::ipc::IPC<{ NUM_PROCS as u8 }>,
    analog_comparator: &'static capsules_extra::analog_comparator::AnalogComparator<
        'static,
        nrf52840::acomp::Comparator<'static>,
    >,
    alarm: &'static AlarmDriver,
    i2c_master_slave: &'static capsules_core::i2c_master_slave_driver::I2CMasterSlaveDriver<
        'static,
        nrf52840::i2c::TWI<'static>,
    >,
    spi_controller: &'static capsules_core::spi_controller::Spi<
        'static,
        capsules_core::virtualizers::virtual_spi::VirtualSpiMasterDevice<
            'static,
            nrf52840::spi::SPIM<'static>,
        >,
    >,
    kv_driver: &'static KVDriver,
    scheduler: &'static RoundRobinSched<'static>,
    systick: cortexm4::systick::SysTick,
}

impl SyscallDriverLookup for Platform {
    fn with_driver<F, R>(&self, driver_num: usize, f: F) -> R
    where
        F: FnOnce(Option<&dyn kernel::syscall::SyscallDriver>) -> R,
    {
        match driver_num {
            capsules_core::console::DRIVER_NUM => f(Some(self.console)),
            capsules_core::gpio::DRIVER_NUM => f(Some(self.gpio)),
            capsules_core::alarm::DRIVER_NUM => f(Some(self.alarm)),
            capsules_core::led::DRIVER_NUM => f(Some(self.led)),
            capsules_core::button::DRIVER_NUM => f(Some(self.button)),
            capsules_core::rng::DRIVER_NUM => f(Some(self.rng)),
            capsules_core::adc::DRIVER_NUM => f(Some(self.adc)),
            capsules_extra::ble_advertising_driver::DRIVER_NUM => f(Some(self.ble_radio)),
            capsules_extra::temperature::DRIVER_NUM => f(Some(self.temp)),
            capsules_extra::analog_comparator::DRIVER_NUM => f(Some(self.analog_comparator)),
            kernel::ipc::DRIVER_NUM => f(Some(&self.ipc)),
            capsules_core::i2c_master_slave_driver::DRIVER_NUM => f(Some(self.i2c_master_slave)),
            capsules_core::spi_controller::DRIVER_NUM => f(Some(self.spi_controller)),
            capsules_extra::kv_driver::DRIVER_NUM => f(Some(self.kv_driver)),
            _ => f(None),
        }
    }
}

impl KernelResources<Chip> for Platform {
    type SyscallDriverLookup = Self;
    type SyscallFilter = ();
    type ProcessFault = ();
    type Scheduler = RoundRobinSched<'static>;
    type SchedulerTimer = cortexm4::systick::SysTick;
    type WatchDog = ();
    type ContextSwitchCallback = ();

    fn syscall_driver_lookup(&self) -> &Self::SyscallDriverLookup {
        self
    }
    fn syscall_filter(&self) -> &Self::SyscallFilter {
        &()
    }
    fn process_fault(&self) -> &Self::ProcessFault {
        &()
    }
    fn scheduler(&self) -> &Self::Scheduler {
        self.scheduler
    }
    fn scheduler_timer(&self) -> &Self::SchedulerTimer {
        &self.systick
    }
    fn watchdog(&self) -> &Self::WatchDog {
        &()
    }
    fn context_switch_callback(&self) -> &Self::ContextSwitchCallback {
        &()
    }
}

/// Create the capsules needed for the in-kernel UDP and 15.4 stack.
pub unsafe fn ieee802154_udp(
    board_kernel: &'static kernel::Kernel,
    nrf52840_peripherals: &'static Nrf52840DefaultPeripherals<'static>,
    mux_alarm: &'static MuxAlarm<nrf52840::rtc::Rtc>,
) -> (
    &'static Eui64Driver,
    &'static Ieee802154Driver,
    &'static capsules_extra::net::udp::UDPDriver<'static>,
) {
    //--------------------------------------------------------------------------
    // AES
    //--------------------------------------------------------------------------

    let aes_mux =
        components::ieee802154::MuxAes128ccmComponent::new(&nrf52840_peripherals.nrf52.ecb)
            .finalize(components::mux_aes128ccm_component_static!(
                nrf52840::aes::AesECB
            ));

    //--------------------------------------------------------------------------
    // 802.15.4
    //--------------------------------------------------------------------------

    let device_id = (*addr_of!(nrf52840::ficr::FICR_INSTANCE)).id();
    let device_id_bottom_16: u16 = u16::from_le_bytes([device_id[0], device_id[1]]);

    let eui64_driver = components::eui64::Eui64Component::new(u64::from_le_bytes(device_id))
        .finalize(components::eui64_component_static!());

    let (ieee802154_driver, mux_mac) = components::ieee802154::Ieee802154Component::new(
        board_kernel,
        capsules_extra::ieee802154::DRIVER_NUM,
        &nrf52840_peripherals.ieee802154_radio,
        aes_mux,
        PAN_ID,
        device_id_bottom_16,
        device_id,
    )
    .finalize(components::ieee802154_component_static!(
        nrf52840::ieee802154_radio::Radio,
        nrf52840::aes::AesECB<'static>
    ));

    //--------------------------------------------------------------------------
    // UDP
    //--------------------------------------------------------------------------

    let local_ip_ifaces = static_init!(
        [IPAddr; 3],
        [
            IPAddr::generate_from_mac(capsules_extra::net::ieee802154::MacAddress::Long(device_id)),
            IPAddr([
                0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d,
                0x1e, 0x1f,
            ]),
            IPAddr::generate_from_mac(capsules_extra::net::ieee802154::MacAddress::Short(
                device_id_bottom_16
            )),
        ]
    );

    let (udp_send_mux, udp_recv_mux, udp_port_table) = components::udp_mux::UDPMuxComponent::new(
        mux_mac,
        DEFAULT_CTX_PREFIX_LEN,
        DEFAULT_CTX_PREFIX,
        DST_MAC_ADDR,
        MacAddress::Long(device_id),
        local_ip_ifaces,
        mux_alarm,
    )
    .finalize(components::udp_mux_component_static!(
        nrf52840::rtc::Rtc,
        Ieee802154MacDevice
    ));

    // UDP driver initialization happens here
    let udp_driver = components::udp_driver::UDPDriverComponent::new(
        board_kernel,
        capsules_extra::net::udp::driver::DRIVER_NUM,
        udp_send_mux,
        udp_recv_mux,
        udp_port_table,
        local_ip_ifaces,
    )
    .finalize(components::udp_driver_component_static!(nrf52840::rtc::Rtc));

    (eui64_driver, ieee802154_driver, udp_driver)
}

/// This is in a separate, inline(never) function so that its stack frame is
/// removed when this function returns. Otherwise, the stack space used for
/// these static_inits is wasted.
#[inline(never)]
pub unsafe fn start_no_pconsole() -> (
    &'static kernel::Kernel,
    Platform,
    &'static Chip,
    &'static Nrf52840DefaultPeripherals<'static>,
    &'static MuxAlarm<'static, nrf52840::rtc::Rtc<'static>>,
) {
    //--------------------------------------------------------------------------
    // INITIAL SETUP
    //--------------------------------------------------------------------------

    // Apply errata fixes and enable interrupts.
    nrf52840::init();

    // Set up peripheral drivers. Called in separate function to reduce stack
    // usage.
    let ieee802154_ack_buf = static_init!(
        [u8; nrf52840::ieee802154_radio::ACK_BUF_SIZE],
        [0; nrf52840::ieee802154_radio::ACK_BUF_SIZE]
    );
    // Initialize chip peripheral drivers
    let nrf52840_peripherals = static_init!(
        Nrf52840DefaultPeripherals,
        Nrf52840DefaultPeripherals::new(ieee802154_ack_buf)
    );

    // Set up circular peripheral dependencies.
    nrf52840_peripherals.init();
    let base_peripherals = &nrf52840_peripherals.nrf52;

    // Configure kernel debug GPIOs as early as possible.
    kernel::debug::assign_gpios(
        Some(&nrf52840_peripherals.gpio_port[LED1_PIN]),
        Some(&nrf52840_peripherals.gpio_port[LED2_PIN]),
        Some(&nrf52840_peripherals.gpio_port[LED3_PIN]),
    );

    // Choose the channel for serial output. This board can be configured to use
    // either the Segger RTT channel or via UART with traditional TX/RX GPIO
    // pins.
    let uart_channel = if USB_DEBUGGING {
        // Initialize early so any panic beyond this point can use the RTT
        // memory object.
        let rtt_memory_refs = components::segger_rtt::SeggerRttMemoryComponent::new()
            .finalize(components::segger_rtt_memory_component_static!());

        // XXX: This is inherently unsafe as it aliases the mutable reference to
        // rtt_memory. This aliases reference is only used inside a panic
        // handler, which should be OK, but maybe we should use a const
        // reference to rtt_memory and leverage interior mutability instead.
        self::io::set_rtt_memory(&*core::ptr::from_mut(rtt_memory_refs.rtt_memory));

        UartChannel::Rtt(rtt_memory_refs)
    } else {
        UartChannel::Pins(UartPins::new(UART_RTS, UART_TXD, UART_CTS, UART_RXD))
    };

    // Create an array to hold process references.
    let processes = components::process_array::ProcessArrayComponent::new()
        .finalize(components::process_array_component_static!(NUM_PROCS));
    PROCESSES = Some(processes);

    // Setup space to store the core kernel data structure.
    let board_kernel = static_init!(kernel::Kernel, kernel::Kernel::new(processes.as_slice()));

    // Create (and save for panic debugging) a chip object to setup low-level
    // resources (e.g. MPU, systick).
    let chip = static_init!(Chip, nrf52840::chip::NRF52::new(nrf52840_peripherals));
    CHIP = Some(chip);

    // Do nRF configuration and setup. This is shared code with other nRF-based
    // platforms.
    nrf52_components::startup::NrfStartupComponent::new(
        false,
        BUTTON_RST_PIN,
        nrf52840::uicr::Regulator0Output::DEFAULT,
        &base_peripherals.nvmc,
    )
    .finalize(());

    //--------------------------------------------------------------------------
    // CAPABILITIES
    //--------------------------------------------------------------------------

    // Create capabilities that the board needs to call certain protected kernel
    // functions.
    let memory_allocation_capability = create_capability!(capabilities::MemoryAllocationCapability);
    let gpio_port = &nrf52840_peripherals.gpio_port;

    //--------------------------------------------------------------------------
    // GPIO
    //--------------------------------------------------------------------------

    // Expose the D0-D13 Arduino GPIO pins to userspace.
    let gpio = components::gpio::GpioComponent::new(
        board_kernel,
        capsules_core::gpio::DRIVER_NUM,
        components::gpio_component_helper!(
            nrf52840::gpio::GPIOPin,
            0 => &nrf52840_peripherals.gpio_port[Pin::P1_01],
            1 => &nrf52840_peripherals.gpio_port[Pin::P1_02],
            2 => &nrf52840_peripherals.gpio_port[Pin::P1_03],
            3 => &nrf52840_peripherals.gpio_port[Pin::P1_04],
            4 => &nrf52840_peripherals.gpio_port[Pin::P1_05],
            5 => &nrf52840_peripherals.gpio_port[Pin::P1_06],
            6 => &nrf52840_peripherals.gpio_port[Pin::P1_07],
            7 => &nrf52840_peripherals.gpio_port[Pin::P1_08],
            // Avoid exposing the I2C pins to userspace, as these are used in
            // some tutorials (e.g., `nrf52840dk-thread-tutorial`).
            //
            // In the future we might want to make this configurable.
            //
            // 8 => &nrf52840_peripherals.gpio_port[Pin::P1_10],
            // 9 => &nrf52840_peripherals.gpio_port[Pin::P1_11],
            10 => &nrf52840_peripherals.gpio_port[Pin::P1_12],
            11 => &nrf52840_peripherals.gpio_port[Pin::P1_13],
            12 => &nrf52840_peripherals.gpio_port[Pin::P1_14],
            13 => &nrf52840_peripherals.gpio_port[Pin::P1_15],
        ),
    )
    .finalize(components::gpio_component_static!(nrf52840::gpio::GPIOPin));

    //--------------------------------------------------------------------------
    // BUTTONS
    //--------------------------------------------------------------------------

    let button = components::button::ButtonComponent::new(
        board_kernel,
        capsules_core::button::DRIVER_NUM,
        components::button_component_helper!(
            nrf52840::gpio::GPIOPin,
            (
                &nrf52840_peripherals.gpio_port[BUTTON1_PIN],
                kernel::hil::gpio::ActivationMode::ActiveLow,
                kernel::hil::gpio::FloatingState::PullUp
            ),
            (
                &nrf52840_peripherals.gpio_port[BUTTON2_PIN],
                kernel::hil::gpio::ActivationMode::ActiveLow,
                kernel::hil::gpio::FloatingState::PullUp
            ),
            (
                &nrf52840_peripherals.gpio_port[BUTTON3_PIN],
                kernel::hil::gpio::ActivationMode::ActiveLow,
                kernel::hil::gpio::FloatingState::PullUp
            ),
            (
                &nrf52840_peripherals.gpio_port[BUTTON4_PIN],
                kernel::hil::gpio::ActivationMode::ActiveLow,
                kernel::hil::gpio::FloatingState::PullUp
            )
        ),
    )
    .finalize(components::button_component_static!(
        nrf52840::gpio::GPIOPin
    ));

    //--------------------------------------------------------------------------
    // LEDs
    //--------------------------------------------------------------------------

    let led = components::led::LedsComponent::new().finalize(components::led_component_static!(
        LedLow<'static, nrf52840::gpio::GPIOPin>,
        LedLow::new(&nrf52840_peripherals.gpio_port[LED1_PIN]),
        LedLow::new(&nrf52840_peripherals.gpio_port[LED2_PIN]),
        LedLow::new(&nrf52840_peripherals.gpio_port[LED3_PIN]),
        LedLow::new(&nrf52840_peripherals.gpio_port[LED4_PIN]),
    ));

    //--------------------------------------------------------------------------
    // TIMER
    //--------------------------------------------------------------------------

    let rtc = &base_peripherals.rtc;
    let _ = rtc.start();
    let mux_alarm = components::alarm::AlarmMuxComponent::new(rtc)
        .finalize(components::alarm_mux_component_static!(nrf52840::rtc::Rtc));
    let alarm = components::alarm::AlarmDriverComponent::new(
        board_kernel,
        capsules_core::alarm::DRIVER_NUM,
        mux_alarm,
    )
    .finalize(components::alarm_component_static!(nrf52840::rtc::Rtc));

    //--------------------------------------------------------------------------
    // UART & CONSOLE & DEBUG
    //--------------------------------------------------------------------------

    let uart_channel = nrf52_components::UartChannelComponent::new(
        uart_channel,
        mux_alarm,
        &base_peripherals.uarte0,
    )
    .finalize(nrf52_components::uart_channel_component_static!(
        nrf52840::rtc::Rtc
    ));

    // Tool for displaying information about processes.
    let process_printer = components::process_printer::ProcessPrinterTextComponent::new()
        .finalize(components::process_printer_text_component_static!());
    PROCESS_PRINTER = Some(process_printer);

    // Virtualize the UART channel for the console and for kernel debug.
    let uart_mux = components::console::UartMuxComponent::new(uart_channel, 115200)
        .finalize(components::uart_mux_component_static!());

    // Create the process console, an interactive terminal for managing
    // processes.
    let pconsole = components::process_console::ProcessConsoleComponent::new(
        board_kernel,
        uart_mux,
        mux_alarm,
        process_printer,
        Some(cortexm4::support::reset),
    )
    .finalize(components::process_console_component_static!(
        nrf52840::rtc::Rtc<'static>
    ));

    // Setup the serial console for userspace.
    let console = components::console::ConsoleComponent::new(
        board_kernel,
        capsules_core::console::DRIVER_NUM,
        uart_mux,
    )
    .finalize(components::console_component_static!());

    // Create the debugger object that handles calls to `debug!()`.
    components::debug_writer::DebugWriterComponent::new(
        uart_mux,
        create_capability!(capabilities::SetDebugWriterCapability),
    )
    .finalize(components::debug_writer_component_static!());

    //--------------------------------------------------------------------------
    // BLE
    //--------------------------------------------------------------------------

    let ble_radio = components::ble::BLEComponent::new(
        board_kernel,
        capsules_extra::ble_advertising_driver::DRIVER_NUM,
        &base_peripherals.ble_radio,
        mux_alarm,
    )
    .finalize(components::ble_component_static!(
        nrf52840::rtc::Rtc,
        nrf52840::ble_radio::Radio
    ));

    //--------------------------------------------------------------------------
    // TEMPERATURE (internal)
    //--------------------------------------------------------------------------

    let temp = components::temperature::TemperatureComponent::new(
        board_kernel,
        capsules_extra::temperature::DRIVER_NUM,
        &base_peripherals.temp,
    )
    .finalize(components::temperature_component_static!(
        nrf52840::temperature::Temp
    ));

    //--------------------------------------------------------------------------
    // RANDOM NUMBER GENERATOR
    //--------------------------------------------------------------------------

    let rng = components::rng::RngComponent::new(
        board_kernel,
        capsules_core::rng::DRIVER_NUM,
        &base_peripherals.trng,
    )
    .finalize(components::rng_component_static!(nrf52840::trng::Trng));

    //--------------------------------------------------------------------------
    // ADC
    //--------------------------------------------------------------------------

    let adc_channels = static_init!(
        [nrf52840::adc::AdcChannelSetup; 6],
        [
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput1),
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput2),
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput4),
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput5),
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput6),
            nrf52840::adc::AdcChannelSetup::new(nrf52840::adc::AdcChannel::AnalogInput7),
        ]
    );
    let adc = components::adc::AdcDedicatedComponent::new(
        &base_peripherals.adc,
        adc_channels,
        board_kernel,
        capsules_core::adc::DRIVER_NUM,
    )
    .finalize(components::adc_dedicated_component_static!(
        nrf52840::adc::Adc
    ));

    //--------------------------------------------------------------------------
    // SPI
    //--------------------------------------------------------------------------

    let mux_spi = components::spi::SpiMuxComponent::new(&base_peripherals.spim0)
        .finalize(components::spi_mux_component_static!(nrf52840::spi::SPIM));

    // Create the SPI system call capsule.
    let spi_controller = components::spi::SpiSyscallComponent::new(
        board_kernel,
        mux_spi,
        kernel::hil::spi::cs::IntoChipSelect::<_, kernel::hil::spi::cs::ActiveLow>::into_cs(
            &gpio_port[SPI_CS],
        ),
        capsules_core::spi_controller::DRIVER_NUM,
    )
    .finalize(components::spi_syscall_component_static!(
        nrf52840::spi::SPIM
    ));

    base_peripherals.spim0.configure(
        nrf52840::pinmux::Pinmux::new(SPI_MOSI as u32),
        nrf52840::pinmux::Pinmux::new(SPI_MISO as u32),
        nrf52840::pinmux::Pinmux::new(SPI_CLK as u32),
    );

    //--------------------------------------------------------------------------
    // ONBOARD EXTERNAL FLASH
    //--------------------------------------------------------------------------

    let mx25r6435f = components::mx25r6435f::Mx25r6435fComponent::new(
        Some(&gpio_port[SPI_MX25R6435F_WRITE_PROTECT_PIN]),
        Some(&gpio_port[SPI_MX25R6435F_HOLD_PIN]),
        &gpio_port[SPI_MX25R6435F_CHIP_SELECT],
        mux_alarm,
        mux_spi,
    )
    .finalize(components::mx25r6435f_component_static!(
        nrf52840::spi::SPIM,
        nrf52840::gpio::GPIOPin,
        nrf52840::rtc::Rtc
    ));

    //--------------------------------------------------------------------------
    // TICKV
    //--------------------------------------------------------------------------

    // Static buffer to use when reading/writing flash for TicKV.
    let page_buffer = static_init!(
        <Mx25r6435f as kernel::hil::flash::Flash>::Page,
        <Mx25r6435f as kernel::hil::flash::Flash>::Page::default()
    );

    // SipHash for creating TicKV hashed keys.
    let sip_hash = components::siphash::Siphasher24Component::new()
        .finalize(components::siphasher24_component_static!());

    // TicKV with Tock wrapper/interface.
    let tickv = components::tickv::TicKVDedicatedFlashComponent::new(
        sip_hash,
        mx25r6435f,
        0, // start at the beginning of the flash chip
        (capsules_extra::mx25r6435f::SECTOR_SIZE as usize) * 32, // arbitrary size of 32 pages
        page_buffer,
    )
    .finalize(components::tickv_dedicated_flash_component_static!(
        Mx25r6435f,
        Siphasher24,
        TICKV_PAGE_SIZE,
    ));

    // KVSystem interface to KV (built on TicKV).
    let tickv_kv_store = components::kv::TicKVKVStoreComponent::new(tickv).finalize(
        components::tickv_kv_store_component_static!(
            TicKVDedicatedFlash,
            capsules_extra::tickv::TicKVKeyType,
        ),
    );

    let kv_store_permissions = components::kv::KVStorePermissionsComponent::new(tickv_kv_store)
        .finalize(components::kv_store_permissions_component_static!(
            TicKVKVStore
        ));

    // Share the KV stack with a mux.
    let mux_kv = components::kv::KVPermissionsMuxComponent::new(kv_store_permissions).finalize(
        components::kv_permissions_mux_component_static!(KVStorePermissions),
    );

    // Create a virtual component for the userspace driver.
    let virtual_kv_driver = components::kv::VirtualKVPermissionsComponent::new(mux_kv).finalize(
        components::virtual_kv_permissions_component_static!(KVStorePermissions),
    );

    // Userspace driver for KV.
    let kv_driver = components::kv::KVDriverComponent::new(
        virtual_kv_driver,
        board_kernel,
        capsules_extra::kv_driver::DRIVER_NUM,
    )
    .finalize(components::kv_driver_component_static!(
        VirtualKVPermissions
    ));

    //--------------------------------------------------------------------------
    // I2C CONTROLLER/TARGET
    //--------------------------------------------------------------------------

    let i2c_master_slave = components::i2c::I2CMasterSlaveDriverComponent::new(
        board_kernel,
        capsules_core::i2c_master_slave_driver::DRIVER_NUM,
        &base_peripherals.twi1,
    )
    .finalize(components::i2c_master_slave_component_static!(
        nrf52840::i2c::TWI
    ));

    base_peripherals.twi1.configure(
        nrf52840::pinmux::Pinmux::new(I2C_SCL_PIN as u32),
        nrf52840::pinmux::Pinmux::new(I2C_SDA_PIN as u32),
    );
    base_peripherals.twi1.set_speed(nrf52840::i2c::Speed::K400);

    //--------------------------------------------------------------------------
    // ANALOG COMPARATOR
    //--------------------------------------------------------------------------

    // Initialize AC using AIN5 (P0.29) as VIN+ and VIN- as AIN0 (P0.02)
    // These are hardcoded pin assignments specified in the driver
    let analog_comparator = components::analog_comparator::AnalogComparatorComponent::new(
        &base_peripherals.acomp,
        components::analog_comparator_component_helper!(
            nrf52840::acomp::Channel,
            &*addr_of!(nrf52840::acomp::CHANNEL_AC0)
        ),
        board_kernel,
        capsules_extra::analog_comparator::DRIVER_NUM,
    )
    .finalize(components::analog_comparator_component_static!(
        nrf52840::acomp::Comparator
    ));

    //--------------------------------------------------------------------------
    // NRF CLOCK SETUP
    //--------------------------------------------------------------------------

    nrf52_components::NrfClockComponent::new(&base_peripherals.clock).finalize(());

    //--------------------------------------------------------------------------
    // USB EXAMPLES
    //--------------------------------------------------------------------------
    // Uncomment to experiment with this.

    // // Create the strings we include in the USB descriptor.
    // let strings = static_init!(
    //     [&str; 3],
    //     [
    //         "Nordic Semiconductor", // Manufacturer
    //         "nRF52840dk - TockOS",  // Product
    //         "serial0001",           // Serial number
    //     ]
    // );

    // CTAP Example
    //
    // let (ctap, _ctap_driver) = components::ctap::CtapComponent::new(
    //     board_kernel,
    //     capsules_extra::ctap::DRIVER_NUM,
    //     &nrf52840_peripherals.usbd,
    //     0x1915, // Nordic Semiconductor
    //     0x503a, // lowRISC generic FS USB
    //     strings,
    // )
    // .finalize(components::ctap_component_static!(nrf52840::usbd::Usbd));

    // ctap.enable();
    // ctap.attach();

    // // Keyboard HID Example
    // type UsbHw = nrf52840::usbd::Usbd<'static>;
    // let usb_device = &nrf52840_peripherals.usbd;

    // let (keyboard_hid, keyboard_hid_driver) = components::keyboard_hid::KeyboardHidComponent::new(
    //     board_kernel,
    //     capsules_core::driver::NUM::KeyboardHid as usize,
    //     usb_device,
    //     0x1915, // Nordic Semiconductor
    //     0x503a,
    //     strings,
    // )
    // .finalize(components::keyboard_hid_component_static!(UsbHw));

    // keyboard_hid.enable();
    // keyboard_hid.attach();

    //--------------------------------------------------------------------------
    // PLATFORM SETUP, SCHEDULER, AND START KERNEL LOOP
    //--------------------------------------------------------------------------

    let scheduler = components::sched::round_robin::RoundRobinComponent::new(processes)
        .finalize(components::round_robin_component_static!(NUM_PROCS));

    let platform = Platform {
        button,
        ble_radio,
        pconsole,
        console,
        led,
        gpio,
        rng,
        adc,
        temp,
        alarm,
        analog_comparator,
        ipc: kernel::ipc::IPC::new(
            board_kernel,
            kernel::ipc::DRIVER_NUM,
            &memory_allocation_capability,
        ),
        i2c_master_slave,
        spi_controller,
        kv_driver,
        scheduler,
        systick: cortexm4::systick::SysTick::new_with_calibration(64000000),
    };

    base_peripherals.adc.calibrate();

    debug!("Initialization complete. Entering main loop\r");
    debug!("{}", &*addr_of!(nrf52840::ficr::FICR_INSTANCE));

    (
        board_kernel,
        platform,
        chip,
        nrf52840_peripherals,
        mux_alarm,
    )
}

/// This is in a separate, inline(never) function so that its stack frame is
/// removed when this function returns. Otherwise, the stack space used for
/// these static_inits is wasted.
#[inline(never)]
pub unsafe fn start() -> (
    &'static kernel::Kernel,
    Platform,
    &'static Chip,
    &'static Nrf52840DefaultPeripherals<'static>,
    &'static MuxAlarm<'static, nrf52840::rtc::Rtc<'static>>,
) {
    let (kernel, platform, chip, peripherals, mux_alarm) = start_no_pconsole();
    let _ = platform.pconsole.start();
    (kernel, platform, chip, peripherals, mux_alarm)
}