Hardware Reference
In-Depth Information
7
Click Write and wait for the imaging process to complete. (This step could take about
15-30 minutes, so be patient.)
8
Exit Win32DiskImager and eject the SD card that should now contain your OS.
Creating an SD Card with Linux
With Linux, it's easiest to create the SD card image from the command line, as detailed in the
following steps.
1
Start a terminal and use the
cd
command to change to the directory containing the file
you downloaded (for example,
cd Downloads
).
2
Unzip the downloaded file by typing
unzip
followed by the downloaded filename (for
example,
unzip 2012-10-28-wheezy-raspbian.zip
).
3
List the image files in the current directory by typing
ls *.img
and make sure that
the extracted image file is listed.
4
Calculate the checksum to ensure that the downloaded file is not corrupt or hasn't
been tampered with. To do this, type the following:
sha1sum 2012-10-28-wheezy-raspbian.zip
Make sure that the result matches with the SHA-1 checksum given on the
http://
raspberrypi.org/download
page. Although it is unlikely that they will differ, if
they do, try downloading and unzipping again.
5
Insert an SD card. Make sure there's no data on it that you want to save, because it will
be completely overwritten.
6
Type
dmesg
and find the device name that Linux uses to refer to the newly inserted card.
It will usually be named
sdd
,
sde
,
sdf
or something similar. Alternatively, it may be in
the form
mmcblk0
. Use this name wherever you see
sd
X
in the following steps.
Checksums
A
checksum
is an easy way to check whether data has been corrupted. A checksum is a
mathematical sum that is performed by the supplier of the data. When you receive the data,
you perform the same sum and, in most cases, if the answer is the same, you can be
almost certain that the data is the same, without comparing bit by bit. Checksums are used
extensively in computing - in network communications, when processing credit cards and
even in barcodes. Although they are not infallible, they make it much easier to be fairly con-
fident data is correct.
