Fix name: Raspberry Pi 3 Model B

docs/Prerequisites.md

@@ -1,8 +1,8 @@
 ## Prerequisites
 
-### 1. [Raspberry Pi 3 model b](https://www.raspberrypi.org/products/raspberry-pi-3-model-b/) 
+### 1. [Raspberry Pi 3 Model B](https://www.raspberrypi.org/products/raspberry-pi-3-model-b/)
 
-Older versions of Raspberry Pi are not going to work with this tutorial because all lessons are designed to use a 64-bit processor that supports ARMv8 architecture, and such processor is only available in the Raspberry Pi 3. Newer versions, including [Raspberry Pi 3 model b +](https://www.raspberrypi.org/products/raspberry-pi-3-model-b-plus/) should work fine, though I haven't tested it yet.
+Older versions of Raspberry Pi are not going to work with this tutorial because all lessons are designed to use a 64-bit processor that supports ARMv8 architecture, and such processor is only available in the Raspberry Pi 3. Newer versions, including [Raspberry Pi 3 Model B+](https://www.raspberrypi.org/products/raspberry-pi-3-model-b-plus/) should work fine, though I haven't tested it yet.
 
 ### 2. [USB to TTL serial cable](https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=usb+to+ttl+serial+cable&rh=i%3Aaps%2Ck%3Ausb+to+ttl+serial+cable) 
 

docs/lesson01/linux/kernel-startup.md

@@ -34,7 +34,7 @@ When we were working on `Raspberry PI OS` kernel, we used [BCM2835 ARM Periphera
 
 Device tree provides us with the solution to the problem, mentioned above. It is a special format that can be used to describe computer hardware. Device tree specification can be found [here](https://www.devicetree.org/). Before the kernel is executed, bootloader selects proper device tree file and passes it as an argument to the kernel. If you take a look at the files in the boot partition on a Raspberry PI SD card, you can find a lot of `.dtb` files here. `.dtb` are compiled device tree files. You can select some of them in the `config.txt` to enable or disable some Raspberry PI  hardware. This process is described in more details in the [Raspberry PI official documentation](https://www.raspberrypi.org/documentation/configuration/device-tree.md)
 
-Ok, now it is time to take a look at how an actual device tree looks like. As a quick exercise, let's try to find a device tree for [Raspberry PI 3 Model b](https://www.raspberrypi.org/products/raspberry-pi-3-model-b/). From the [documentation](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2837/README.md) we can figure out that `Raspberry PI 3 Model b` uses a chip that is called `BCM2837`. If you search for this name you can find [/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts](https://github.com/torvalds/linux/blob/v4.14/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts)  file. As you might see it just includes the same file from `arm` architecture. This makes a perfect sense because `ARM.v8` processor supports 32-bit mode as well. 
+Ok, now it is time to take a look at how an actual device tree looks like. As a quick exercise, let's try to find a device tree for [Raspberry PI 3 Model B](https://www.raspberrypi.org/products/raspberry-pi-3-model-b/). From the [documentation](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2837/README.md) we can figure out that `Raspberry PI 3 Model B` uses a chip that is called `BCM2837`. If you search for this name you can find [/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts](https://github.com/torvalds/linux/blob/v4.14/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts)  file. As you might see it just includes the same file from `arm` architecture. This makes a perfect sense because `ARM.v8` processor supports 32-bit mode as well.
 
 Next, we can find [bcm2837-rpi-3-b.dts](https://github.com/torvalds/linux/blob/v4.14/arch/arm/boot/dts/bcm2837-rpi-3-b.dts) belonging to the [arm](https://github.com/torvalds/linux/tree/v4.14/arch/arm) architecture. We already saw that device tree files could include on another. This is the case with the  `bcm2837-rpi-3-b.dts` - it only contains those definitions, that are specific for `BCM2837` and reuses everything else. For example,  `bcm2837-rpi-3-b.dts` specifies that [the device now have 1GB of memory](https://github.com/torvalds/linux/blob/v4.14/arch/arm/boot/dts/bcm2837-rpi-3-b.dts#L18).