Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The ioremap() API returns a KVA of the void * type (since it's an address location)"

A block of code is set as follows:

static int __init miscdrv_init(void)
{
    int ret;
    struct device *dev;

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

#define pr_fmt(fmt) "%s:%s(): " fmt, KBUILD_MODNAME, __func__
[...]
#include <linux/miscdevice.h>
#include <linux/fs.h>             
[...]

Any command-line input or output is written as follows:

pi@raspberrypi:~ $ sudo cat /proc/iomem

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."

Warnings or important notes appear like this.

Tips and tricks appear like this.