Revamp deploy.py

Now the script supports more flashing methods: - JLink (with tockloader) - OpenOCD (with tockloader) - pyOCD - Nordic DFU - none (will produce an IntelHex file) Also merged the contributions from: - Yihui Xiong to support the Makerdiary USB dongle board - Dennis Geurts to support Nordic DFU Doc updated accordingly. Imported 2 patches for Tock kernel: - 06-add-set_vector_table_offset.patch (upstream tock/tock#1579) - 07-nrf52-bootloader.patch (upstream tock/tock#1681)
2026-08-28 10:41:01 -07:00 · 2020-03-11 17:54:37 +01:00
parent 8b146440a5
commit e63482af1c
14 changed files with 861 additions and 226 deletions
@@ -1,7 +0,0 @@
-# Target configuration for the CTAP2 app on the nRF52840 chip
-[target.thumbv7em-none-eabi]
-rustflags = [
-  "-C", "link-arg=-Tnrf52840dk_layout.ld",
-  "-C", "relocation-model=static",
-  "-D", "warnings",
-]
@@ -19,8 +19,9 @@ successfully tested on the following boards:

 ## Disclaimer

-This project is proof-of-concept and a research platform. It's still under
-development and as such comes with a few limitations:
+This project is **proof-of-concept and a research platform**. It is **NOT**
+meant for a day to day usage. It's still under development and as such comes
+with a few limitations:

 ### FIDO2

@@ -53,25 +54,17 @@ For a more detailed guide, please refer to our
    ./setup.sh
    ```

-2.  If Tock OS is already installed on your board, move to the next step.
-    Otherwise, just run one of the following commands, depending on the board
-    you have:
+2.  Next step is to install Tock OS as well as the OpenSK application on your
+    board (**Warning**: it will erase the locally stored credentials). Run:

    ```shell
    # Nordic nRF52840-DK board
-    ./deploy.py os --board=nrf52840_dk
+    ./deploy.py --board=nrf52840dk --opensk
    # Nordic nRF52840-Dongle
-    ./deploy.py os --board=nrf52840_dongle
+    ./deploy.py --board=nrf52840_dongle --opensk
    ```

-3.  Next step is to install/update the OpenSK application on your board
-    (**Warning**: it will erase the locally stored credentials). Run:
-
-    ```shell
-    ./deploy.py app --opensk
-    ```
-
-4.  On Linux, you may want to avoid the need for `root` privileges to interact
+3.  On Linux, you may want to avoid the need for `root` privileges to interact
    with the key. For that purpose we provide a udev rule file that can be
    installed with the following command:

@@ -0,0 +1,30 @@
+[package]
+name = "nrf52840_dongle_dfu"
+version = "0.1.0"
+authors = ["Tock Project Developers <tock-dev@googlegroups.com>"]
+build = "build.rs"
+edition = "2018"
+
+[profile.dev]
+panic = "abort"
+lto = false
+opt-level = "z"
+debug = true
+
+[profile.release]
+panic = "abort"
+lto = true
+opt-level = "z"
+debug = true
+
+[[bin]]
+path = "../../third_party/tock/boards/nordic/nrf52840_dongle/src/main.rs"
+name = "nrf52840_dongle_dfu"
+
+[dependencies]
+components = { path = "../../third_party/tock/boards/components" }
+cortexm4 = { path = "../../third_party/tock/arch/cortex-m4" }
+capsules = { path = "../../third_party/tock/capsules" }
+kernel = { path = "../../third_party/tock/kernel" }
+nrf52840 = { path = "../../third_party/tock/chips/nrf52840" }
+nrf52dk_base = { path = "../../third_party/tock/boards/nordic/nrf52dk_base" }
@@ -0,0 +1,4 @@
+fn main() {
+    println!("cargo:rerun-if-changed=layout.ld");
+    println!("cargo:rerun-if-changed=../../third_party/tock/boards/kernel_layout.ld");
+}
@@ -0,0 +1,10 @@
+MEMORY
+{
+  rom (rx)  : ORIGIN = 0x00001000, LENGTH = 188K
+  prog (rx) : ORIGIN = 0x00030000, LENGTH = 832K
+  ram (rwx) : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+MPU_MIN_ALIGN = 8K;
+
+INCLUDE ../../third_party/tock/boards/kernel_layout.ld
@@ -0,0 +1,26 @@
+[package]
+name = "nrf52840_mdk_dfu"
+version = "0.1.0"
+authors = ["Yihui Xiong <yihui.xiong@hotmail.com>"]
+build = "build.rs"
+edition = "2018"
+
+[profile.dev]
+panic = "abort"
+lto = false
+opt-level = "z"
+debug = true
+
+[profile.release]
+panic = "abort"
+lto = true
+opt-level = "z"
+debug = true
+
+[dependencies]
+components = { path = "../../third_party/tock/boards/components" }
+cortexm4 = { path = "../../third_party/tock/arch/cortex-m4" }
+capsules = { path = "../../third_party/tock/capsules" }
+kernel = { path = "../../third_party/tock/kernel" }
+nrf52840 = { path = "../../third_party/tock/chips/nrf52840" }
+nrf52dk_base = { path = "../../third_party/tock/boards/nordic/nrf52dk_base" }
@@ -0,0 +1,4 @@
+fn main() {
+    println!("cargo:rerun-if-changed=layout.ld");
+    println!("cargo:rerun-if-changed=../../third_party/tock/boards/kernel_layout.ld");
+}
@@ -0,0 +1,10 @@
+MEMORY
+{
+  rom (rx)  : ORIGIN = 0x00001000, LENGTH = 188K
+  prog (rx) : ORIGIN = 0x00030000, LENGTH = 832K
+  ram (rwx) : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+MPU_MIN_ALIGN = 8K;
+
+INCLUDE ../../third_party/tock/boards/kernel_layout.ld
@@ -0,0 +1,65 @@
+use core::fmt::Write;
+use core::panic::PanicInfo;
+use cortexm4;
+use kernel::debug;
+use kernel::debug::IoWrite;
+use kernel::hil::led;
+use kernel::hil::uart::{self, Configure};
+use nrf52840::gpio::Pin;
+
+use crate::CHIP;
+use crate::PROCESSES;
+
+struct Writer {
+    initialized: bool,
+}
+
+static mut WRITER: Writer = Writer { initialized: false };
+
+impl Write for Writer {
+    fn write_str(&mut self, s: &str) -> ::core::fmt::Result {
+        self.write(s.as_bytes());
+        Ok(())
+    }
+}
+
+impl IoWrite for Writer {
+    fn write(&mut self, buf: &[u8]) {
+        let uart = unsafe { &mut nrf52840::uart::UARTE0 };
+        if !self.initialized {
+            self.initialized = true;
+            uart.configure(uart::Parameters {
+                baud_rate: 115200,
+                stop_bits: uart::StopBits::One,
+                parity: uart::Parity::None,
+                hw_flow_control: false,
+                width: uart::Width::Eight,
+            });
+        }
+        for &c in buf {
+            unsafe {
+                uart.send_byte(c);
+            }
+            while !uart.tx_ready() {}
+        }
+    }
+}
+
+#[cfg(not(test))]
+#[no_mangle]
+#[panic_handler]
+/// Panic handler
+pub unsafe extern "C" fn panic_fmt(pi: &PanicInfo) -> ! {
+    // The nRF52840 Dongle LEDs (see back of board)
+    const LED1_PIN: Pin = Pin::P0_23;
+    let led = &mut led::LedLow::new(&mut nrf52840::gpio::PORT[LED1_PIN]);
+    let writer = &mut WRITER;
+    debug::panic(
+        &mut [led],
+        writer,
+        pi,
+        &cortexm4::support::nop,
+        &PROCESSES,
+        &CHIP,
+    )
+}
@@ -0,0 +1,123 @@
+//! Tock kernel for the Makerdiary nRF52840 MDK USB dongle.
+//!
+//! It is based on nRF52840 SoC (Cortex M4 core with a BLE transceiver) with
+//! many exported I/O and peripherals.
+
+#![no_std]
+#![no_main]
+#![deny(missing_docs)]
+
+use kernel::component::Component;
+#[allow(unused_imports)]
+use kernel::{debug, debug_gpio, debug_verbose, static_init};
+use nrf52840::gpio::Pin;
+use nrf52dk_base::{SpiPins, UartChannel, UartPins};
+
+// The nRF52840 MDK USB Dongle LEDs
+const LED1_R_PIN: Pin = Pin::P0_23;
+const LED1_G_PIN: Pin = Pin::P0_22;
+const LED1_B_PIN: Pin = Pin::P0_24;
+
+// The nRF52840 Dongle button
+const BUTTON_PIN: Pin = Pin::P0_18;
+const BUTTON_RST_PIN: Pin = Pin::P0_02;
+
+const UART_RTS: Pin = Pin::P0_21;
+const UART_TXD: Pin = Pin::P0_20;
+const UART_CTS: Pin = Pin::P0_03;
+const UART_RXD: Pin = Pin::P0_19;
+
+const SPI_MOSI: Pin = Pin::P0_05;
+const SPI_MISO: Pin = Pin::P0_06;
+const SPI_CLK: Pin = Pin::P0_07;
+
+/// UART Writer
+pub mod io;
+
+// State for loading and holding applications.
+// How should the kernel respond when a process faults.
+const FAULT_RESPONSE: kernel::procs::FaultResponse = kernel::procs::FaultResponse::Panic;
+
+// Number of concurrent processes this platform supports.
+const NUM_PROCS: usize = 8;
+
+// RAM to be shared by all application processes.
+#[link_section = ".app_memory"]
+static mut APP_MEMORY: [u8; 0x3C000] = [0; 0x3C000];
+
+static mut PROCESSES: [Option<&'static dyn kernel::procs::ProcessType>; NUM_PROCS] =
+    [None, None, None, None, None, None, None, None];
+
+// Static reference to chip for panic dumps
+static mut CHIP: Option<&'static nrf52840::chip::Chip> = None;
+
+/// Dummy buffer that causes the linker to reserve enough space for the stack.
+#[no_mangle]
+#[link_section = ".stack_buffer"]
+pub static mut STACK_MEMORY: [u8; 0x1000] = [0; 0x1000];
+
+/// Entry point in the vector table called on hard reset.
+#[no_mangle]
+pub unsafe fn reset_handler() {
+    // Loads relocations and clears BSS
+    nrf52840::init();
+
+    let board_kernel = static_init!(kernel::Kernel, kernel::Kernel::new(&PROCESSES));
+    // GPIOs
+    let gpio = components::gpio::GpioComponent::new(board_kernel).finalize(
+        components::gpio_component_helper!(
+            &nrf52840::gpio::PORT[Pin::P0_04],
+            &nrf52840::gpio::PORT[Pin::P0_05],
+            &nrf52840::gpio::PORT[Pin::P0_06],
+            &nrf52840::gpio::PORT[Pin::P0_07],
+            &nrf52840::gpio::PORT[Pin::P0_08]
+        ),
+    );
+    let button = components::button::ButtonComponent::new(board_kernel).finalize(
+        components::button_component_helper!((
+            &nrf52840::gpio::PORT[BUTTON_PIN],
+            capsules::button::GpioMode::LowWhenPressed,
+            kernel::hil::gpio::FloatingState::PullUp
+        )),
+    );
+
+    let led = components::led::LedsComponent::new().finalize(components::led_component_helper!(
+        (
+            &nrf52840::gpio::PORT[LED1_R_PIN],
+            capsules::led::ActivationMode::ActiveLow
+        ),
+        (
+            &nrf52840::gpio::PORT[LED1_G_PIN],
+            capsules::led::ActivationMode::ActiveLow
+        ),
+        (
+            &nrf52840::gpio::PORT[LED1_B_PIN],
+            capsules::led::ActivationMode::ActiveLow
+        )
+    ));
+    let chip = static_init!(nrf52840::chip::Chip, nrf52840::chip::new());
+    CHIP = Some(chip);
+
+    nrf52dk_base::setup_board(
+        board_kernel,
+        BUTTON_RST_PIN,
+        &nrf52840::gpio::PORT,
+        gpio,
+        LED1_R_PIN,
+        LED1_G_PIN,
+        LED1_B_PIN,
+        led,
+        UartChannel::Pins(UartPins::new(UART_RTS, UART_TXD, UART_CTS, UART_RXD)),
+        &SpiPins::new(SPI_MOSI, SPI_MISO, SPI_CLK),
+        &None,
+        button,
+        true,
+        &mut APP_MEMORY,
+        &mut PROCESSES,
+        FAULT_RESPONSE,
+        nrf52840::uicr::Regulator0Output::V3_0,
+        false,
+        &Some(&nrf52840::usbd::USBD),
+        chip,
+    );
+}
@@ -16,8 +16,9 @@ You will need one the following supported boards:
    scenarios as the JTAG probe is already on the board.
 *   [Nordic nRF52840 Dongle](https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52840-Dongle)
    to have a more practical form factor.
+*   [Makerdiary nRF52840-MDK USB dongle](https://wiki.makerdiary.com/nrf52840-mdk/).

-In the case of the Nordic USB dongle, you will also need the following extra
+In the case of the Nordic USB dongle, you may also need the following extra
 hardware:

 *   a [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) JTAG
@@ -30,13 +31,18 @@ hardware:
    [Tag-Connect TC2050 retainer clip](http://www.tag-connect.com/TC2050-CLIP)
    to keep the spring loaded connector pressed to the PCB.

-Although [OpenOCD](http://openocd.org/) should be supported we encountered some
-issues while trying to flash a firmware with it. Therefore we suggest at the
-moment to use a
-[Segger J-Link](https://www.segger.com/products/debug-probes/j-link/) probe
-instead.
+Additionnaly, OpenSK supports other ways to flash your board:

-This guide **does not** cover how to setup the JTAG probe on your system.
+*   [OpenOCD](http://openocd.org/).
+*   [Segger J-Link](https://www.segger.com/products/debug-probes/j-link/)
+    (default method).
+*   [pyOCD](https://pypi.org/project/pyocd/).
+*   [nrfutil](https://pypi.org/project/nrfutil/) for the USB dongle boards that
+    supports it, which allows you to directly flash a working board over USB
+    without additional hardware.
+
+This guide **does not** cover how to setup the JTAG probe and their related
+tools on your system.

 ### Software

@@ -141,17 +147,17 @@ Our build script `build.rs` is responsible for converting `opensk_cert.pem` and

 1.  Connect a micro USB cable to the JTAG USB port.

-1.  Run our script for compiling/flashing Tock OS on your device (_output may
-    differ_):
+1.  Run our script for compiling/flashing Tock OS and OpenSK on your device
+    (_output may differ_):

    ```shell
-    $ ./deploy.py os --board=nrf52840_dk
+    $ ./deploy.py --board=nrf52840dk --opensk
        info: Updating rust toolchain to nightly-2020-02-03
        info: syncing channel updates for 'nightly-2020-02-03-x86_64-unknown-linux-gnu'
        info: checking for self-updates
        info: component 'rust-std' for target 'thumbv7em-none-eabi' is up to date
        info: Rust toolchain up-to-date
-        info: Installing Tock on board nrf52840_dk
+        info: Building Tock OS for board nrf52840dk
            Compiling tock-registers v0.5.0 (./third_party/tock/libraries/tock-register-interface)
            Compiling tock-cells v0.1.0 (./third_party/tock/libraries/tock-cells)
            Compiling enum_primitive v0.1.0 (./third_party/tock/libraries/enum_primitive)
@@ -166,47 +172,17 @@ Our build script `build.rs` is responsible for converting `opensk_cert.pem` and
            Compiling nrf52840 v0.1.0 (./third_party/tock/chips/nrf52840)
            Compiling components v0.1.0 (./third_party/tock/boards/components)
            Compiling nrf52dk_base v0.1.0 (./third_party/tock/boards/nordic/nrf52dk_base)
-                Finished release [optimized + debuginfo] target(s) in 11.97s
-        [STATUS ] Flashing binar(y|ies) to board...
-        [INFO   ] Using known arch and jtag-device for known board nrf52dk
-        [INFO   ] Finished in 0.284 seconds
-    ```
-
-1.  Run our script for compiling/flashing the OpenSK application on your device
-    (_output may differ_):
-
-    ```shell
-    $ ./deploy.py app --opensk
-    info: Updating rust toolchain to nightly-2020-02-03
-    info: syncing channel updates for 'nightly-2020-02-03-x86_64-unknown-linux-gnu'
-    info: checking for self-updates
-    info: component 'rust-std' for target 'thumbv7em-none-eabi' is up to date
-    info: Rust toolchain up-to-date
-    info: Erasing all installed applications
-    All apps have been erased.
-    info: Building OpenSK application
-        Compiling autocfg v1.0.0
-        Compiling pkg-config v0.3.17
-        Compiling cc v1.0.50
-        Compiling libc v0.2.66
-        Compiling bitflags v1.2.1
-        Compiling foreign-types-shared v0.1.1
-        Compiling openssl v0.10.28
-        Compiling cfg-if v0.1.10
-        Compiling lazy_static v1.4.0
-        Compiling byteorder v1.3.2
-        Compiling linked_list_allocator v0.6.6
-        Compiling arrayref v0.3.6
-        Compiling cbor v0.1.0 (./libraries/cbor)
-        Compiling subtle v2.2.2
-        Compiling foreign-types v0.3.2
-        Compiling libtock v0.1.0 (./third_party/libtock-rs)
-        Compiling crypto v0.1.0 (./libraries/crypto)
-        Compiling openssl-sys v0.9.54
-        Compiling ctap2 v0.1.0 (.)
-            Finished release [optimized] target(s) in 15.34s
-    info: Flashing padding application
-    info: Installing Tock application ctap2
+                Finished release [optimized + debuginfo] target(s) in 13.15s
+        info: Converting Tock OS file into a binary
+        info: Building OpenSK application
+            Finished release [optimized] target(s) in 0.02s
+        info: Generating Tock TAB file for application/example ctap2
+        info: Erasing all installed applications
+        All apps have been erased.
+        info: Flashing file third_party/tock/boards/nordic/nrf52840dk/target/thumbv7em-none-eabi/release/nrf52840dk.bin.
+        info: Flashing padding application
+        info: Installing Tock application ctap2
+        info: You're all set!
    ```

 1.  Connect a micro USB cable to the device USB port.
@@ -217,6 +193,8 @@ the board in order to see your OpenSK device on your system.

 #### Nordic nRF52840 Dongle

+##### Using external programmer (JLink, OpenOCD, etc.)
+
 ![Nordic dongle](img/dongle_front.jpg)

 1.  The JTAG probe used for programming won't provide power to the board.
@@ -232,17 +210,18 @@ the board in order to see your OpenSK device on your system.

    ![Nordic dongle retainer clip](img/dongle_clip.jpg)

-1.  Run our script for compiling/flashing Tock OS on your device (_output may
-    differ_):
+1.  Depending on the programmer you're using, you may have to adapt the next
+    command line. Run our script for compiling/flashing Tock OS on your device
+    (_output may differ_):

    ```shell
-    $ ./deploy.py os --board=nrf52840_dongle
+    $ ./deploy.py os --board=nrf52840_dongle --programmer=jlink
    info: Updating rust toolchain to nightly-2020-02-03
    info: syncing channel updates for 'nightly-2020-02-03-x86_64-unknown-linux-gnu'
    info: checking for self-updates
    info: component 'rust-std' for target 'thumbv7em-none-eabi' is up to date
    info: Rust toolchain up-to-date
-    info: Installing Tock on board nrf52840_dongle
+    info: Building Tock OS for board nrf52840_dongle
        Compiling tock-cells v0.1.0 (./third_party/tock/libraries/tock-cells)
        Compiling tock-registers v0.5.0 (./third_party/tock/libraries/tock-register-interface)
        Compiling enum_primitive v0.1.0 (./third_party/tock/libraries/enum_primitive)
@@ -258,50 +237,39 @@ the board in order to see your OpenSK device on your system.
        Compiling components v0.1.0 (./third_party/tock/boards/components)
        Compiling nrf52dk_base v0.1.0 (./third_party/tock/boards/nordic/nrf52dk_base)
            Finished release [optimized + debuginfo] target(s) in 11.72s
-        [STATUS ] Flashing binar(y|ies) to board...
-        [INFO   ] Using known arch and jtag-device for known board nrf52dk
-        [INFO   ] Finished in 0.280 seconds
-    ```
-
-1.  Run our script for compiling/flashing the OpenSK application on your device
-    (_output may differ_):
-
-    ```shell
-    $ ./deploy.py app --opensk
-    info: Updating rust toolchain to nightly-2020-02-03
-    info: syncing channel updates for 'nightly-2020-02-03-x86_64-unknown-linux-gnu'
-    info: checking for self-updates
-    info: component 'rust-std' for target 'thumbv7em-none-eabi' is up to date
-    info: Rust toolchain up-to-date
+    info: Converting Tock OS file into a binary
+    info: Building OpenSK application
+        Finished release [optimized] target(s) in 0.02s
+    info: Generating Tock TAB file for application/example ctap2
    info: Erasing all installed applications
    All apps have been erased.
-    info: Building OpenSK application
-        Compiling autocfg v1.0.0
-        Compiling pkg-config v0.3.17
-        Compiling cc v1.0.50
-        Compiling libc v0.2.66
-        Compiling bitflags v1.2.1
-        Compiling foreign-types-shared v0.1.1
-        Compiling openssl v0.10.28
-        Compiling cfg-if v0.1.10
-        Compiling lazy_static v1.4.0
-        Compiling byteorder v1.3.2
-        Compiling linked_list_allocator v0.6.6
-        Compiling arrayref v0.3.6
-        Compiling cbor v0.1.0 (./libraries/cbor)
-        Compiling subtle v2.2.2
-        Compiling foreign-types v0.3.2
-        Compiling libtock v0.1.0 (./third_party/libtock-rs)
-        Compiling crypto v0.1.0 (./libraries/crypto)
-        Compiling openssl-sys v0.9.54
-        Compiling ctap2 v0.1.0 (.)
-            Finished release [optimized] target(s) in 15.34s
+    info: Flashing file third_party/tock/boards/nordic/nrf52840_dongle/target/thumbv7em-none-eabi/release/nrf52840_dongle.bin.
    info: Flashing padding application
    info: Installing Tock application ctap2
+    info: You're all set!
    ```

 1.  Remove the programming cable and the USB-A extension cable.

+### Advanced installation
+
+Although flashing using a Segger JLink probe is the officially supported way,
+our tool, `deploy.py` also supports other methods:
+
+*   OpenOCD: `./deploy.py --board=nrf52840_dongle --opensk --programmer=openocd`
+*   pyOCD: `./deploy.py --board=nrf52840_dongle --opensk --programmer=pyocd`
+*   Nordic DFU: `./deploy.py --board=nrf52840_dongle --opensk
+    --programmer=nordicdfu`
+*   Custom: `./deploy.py --board=nrf52840_dongle --opensk --programmer=none`. In
+    this case, an IntelHex file will be created and how to program a board is
+    left to the user.
+
+If your board is already flashed with Tock OS, you may skip installing it:
+`./deploy.py --board=nrf52840dk --opensk --no-tockos`
+
+For more options, we invite you to read the help of our `deploy.py` script by
+running `./deploy.py --help`.
+
 ### Installing the udev rule (Linux only)

 By default on Linux, a USB device will require root privilege in order interact
@@ -0,0 +1,23 @@
+diff --git a/arch/cortex-m/src/scb.rs b/arch/cortex-m/src/scb.rs
+index 8107f16..a271db9 100644
+--- a/arch/cortex-m/src/scb.rs
+++ b/arch/cortex-m/src/scb.rs
+@@ -9,7 +9,7 @@ use kernel::common::StaticRef;
+ struct ScbRegisters {
+     cpuid: VolatileCell<u32>,
+     icsr: VolatileCell<u32>,
+-    vtor: VolatileCell<u32>,
+    vtor: VolatileCell<*const ()>,
+     aircr: VolatileCell<u32>,
+     scr: VolatileCell<u32>,
+     ccr: VolatileCell<u32>,
+@@ -54,3 +54,8 @@ pub unsafe fn reset() {
+     let reset = (0x5FA << 16) | (aircr & (0x7 << 8)) | (1 << 2);
+     SCB.aircr.set(reset);
+ }
+
+/// relocate interrupt vector table
+pub unsafe fn set_vector_table_offset(offset: *const ()) {
+    SCB.vtor.set(offset);
+}
+
@@ -0,0 +1,21 @@
+diff --git a/chips/nrf52/src/crt1.rs b/chips/nrf52/src/crt1.rs
+index 9703aac..281ceeb 100644
+--- a/chips/nrf52/src/crt1.rs
+++ b/chips/nrf52/src/crt1.rs
+@@ -1,4 +1,4 @@
+-use cortexm4::{generic_isr, hard_fault_handler, nvic, svc_handler, systick_handler};
+use cortexm4::{generic_isr, hard_fault_handler, nvic, scb, svc_handler, systick_handler};
+ use tock_rt0;
+ 
+ /*
+@@ -168,5 +168,9 @@ pub unsafe extern "C" fn init() {
+     tock_rt0::init_data(&mut _etext, &mut _srelocate, &mut _erelocate);
+     tock_rt0::zero_bss(&mut _szero, &mut _ezero);
+ 
+    // Ensure that we are compatible with a bootloader.
+    // For this we need to offset our vector table
+    scb::set_vector_table_offset(BASE_VECTORS.as_ptr() as *const ());
+
+     nvic::enable_all();
+ }
+