7 files changed, 26 insertions, 12 deletions
diff --git a/src/doc/embedded-book/src/assets/verify.jpeg b/src/doc/embedded-book/src/assets/verify.jpeg
index a6e9376c5..ed4664578 100644
--- a/src/doc/embedded-book/src/assets/verify.jpeg
+++ b/src/doc/embedded-book/src/assets/verify.jpeg
diff --git a/src/doc/embedded-book/src/collections/index.md b/src/doc/embedded-book/src/collections/index.md
index 7319a397a..aa03666ac 100644
--- a/src/doc/embedded-book/src/collections/index.md
+++ b/src/doc/embedded-book/src/collections/index.md
@@ -49,9 +49,8 @@ in your program instead of this allocator.
 ``` rust,ignore
 // Bump pointer allocator implementation
 
-extern crate cortex_m;
-
-use core::alloc::GlobalAlloc;
+use core::alloc::{GlobalAlloc, Layout};
+use core::cell::UnsafeCell;
 use core::ptr;
 
 use cortex_m::interrupt;
@@ -144,8 +143,7 @@ as they are exact same implementation.
 allocator. Just `use` its collections and proceed to instantiate them:
 
 ```rust,ignore
-extern crate heapless; // v0.4.x
-
+// heapless version: v0.4.x
 use heapless::Vec;
 use heapless::consts::*;
 
@@ -155,6 +153,7 @@ fn main() -> ! {
 
     xs.push(42).unwrap();
     assert_eq!(xs.pop(), Some(42));
+    loop {}
 }
 ```
 
diff --git a/src/doc/embedded-book/src/interoperability/c-with-rust.md b/src/doc/embedded-book/src/interoperability/c-with-rust.md
index d5d8db39b..6bec3bd87 100644
--- a/src/doc/embedded-book/src/interoperability/c-with-rust.md
+++ b/src/doc/embedded-book/src/interoperability/c-with-rust.md
@@ -125,8 +125,6 @@ For projects with limited dependencies or complexity, or for projects where it i
 In the simplest case of compiling a single C file as a dependency to a static library, an example `build.rs` script using the [`cc` crate] would look like this:
 
 ```rust,ignore
-extern crate cc;
-
 fn main() {
     cc::Build::new()
         .file("foo.c")
diff --git a/src/doc/embedded-book/src/intro/install/macos.md b/src/doc/embedded-book/src/intro/install/macos.md
index b3e51bcf1..9a797563a 100644
--- a/src/doc/embedded-book/src/intro/install/macos.md
+++ b/src/doc/embedded-book/src/intro/install/macos.md
@@ -1,8 +1,11 @@
 # macOS
 
-All the tools can be install using [Homebrew]:
+All the tools can be installed using [Homebrew] or [MacPorts]:
 
 [Homebrew]: http://brew.sh/
+[MacPorts]: https://www.macports.org/
+
+## Install tools with [Homebrew]
 
 ``` text
 $ # GDB
@@ -20,6 +23,21 @@ $ brew install qemu
 $ brew install --HEAD openocd
 ```
 
+## Install tools with [MacPorts]
+
+``` text
+$ # GDB
+$ sudo port install arm-none-eabi-gcc
+
+$ # OpenOCD
+$ sudo port install openocd
+
+$ # QEMU
+$ sudo port install qemu
+```
+
+
+
 That's all! Go to the [next section].
 
 [next section]: verify.md
diff --git a/src/doc/embedded-book/src/intro/install/verify.md b/src/doc/embedded-book/src/intro/install/verify.md
index 921db8cc7..e60911dc3 100644
--- a/src/doc/embedded-book/src/intro/install/verify.md
+++ b/src/doc/embedded-book/src/intro/install/verify.md
@@ -8,7 +8,7 @@ discovery board has two USB connectors; use the one labeled "USB ST-LINK" that
 sits on the center of the edge of the board.
 
 Also check that the ST-LINK header is populated. See the picture below; the
-ST-LINK header is circled in red.
+ST-LINK header is highlighted.
 
 <p align="center">
 <img title="Connected discovery board" src="../../assets/verify.jpeg">
diff --git a/src/doc/embedded-book/src/peripherals/singletons.md b/src/doc/embedded-book/src/peripherals/singletons.md
index 3f04aa170..1f3a556e8 100644
--- a/src/doc/embedded-book/src/peripherals/singletons.md
+++ b/src/doc/embedded-book/src/peripherals/singletons.md
@@ -61,8 +61,7 @@ This has a small runtime overhead because we must wrap the `SerialPort` structur
 Although we created our own `Peripherals` structure above, it is not necessary to do this for your code. the `cortex_m` crate contains a macro called `singleton!()` that will perform this action for you.
 
 ```rust,ignore
-#[macro_use(singleton)]
-extern crate cortex_m;
+use cortex_m::singleton;
 
 fn main() {
     // OK if `main` is executed only once
diff --git a/src/doc/embedded-book/src/start/registers.md b/src/doc/embedded-book/src/start/registers.md
index d5bb3e0cc..fe184792c 100644
--- a/src/doc/embedded-book/src/start/registers.md
+++ b/src/doc/embedded-book/src/start/registers.md
@@ -24,7 +24,7 @@ You may well find that the code you need to access the peripherals in your micro
 
 A board crate is the perfect starting point, if you're new to embedded Rust. They nicely abstract the HW details that might be overwhelming when starting studying this subject, and makes standard tasks easy, like turning a LED on or off. The functionality it exposes varies a lot between boards. Since this book aims at staying hardware agnostic, the board crates won't be covered by this book.
 
-If you want to experiment with the STM32F3DISCOVERY board, it is highly recommmand to take a look at the [stm32f3-discovery] board crate, which provides functionality to blink the board LEDs, access its compass, bluetooth and more. The [Discovery] book offers a great introduction to the use of a board crate.
+If you want to experiment with the STM32F3DISCOVERY board, it is highly recommended to take a look at the [stm32f3-discovery] board crate, which provides functionality to blink the board LEDs, access its compass, bluetooth and more. The [Discovery] book offers a great introduction to the use of a board crate.
 
 But if you're working on a system that doesn't yet have dedicated board crate, or you need functionality not provided by existing crates, read on as we start from the bottom, with the micro-architecture crates.