Difference between revisions of "Loading Linux Images to a Compact Flash Disk"

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{{todo|Review (11.12.13-18:07->KY+);(11.15.13-20:15->MD-)|Klint Youngmeyer|project=oe 4,oe 5,ky,md,revise}}
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{{#seo:
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|title=Loading Linux Images to a Compact Flash Disk
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|titlemode=append
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|keywords=Compact Flash,Linux Image,Firmware Image
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|description=When changing firmware images or creating custom firmware images for your Compact Flash-based machine, it is necessary to perform a few steps to load the firmware image onto the CF card.
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}}
 
When changing firmware images or creating custom firmware images for your Compact Flash-based machine, it is necessary to perform a few steps to load the firmware image onto the CF card.
 
When changing firmware images or creating custom firmware images for your Compact Flash-based machine, it is necessary to perform a few steps to load the firmware image onto the CF card.
 
__TOC__
 
__TOC__
 
==Necessary Tools==
 
==Necessary Tools==
  
−
To perform this procedure, you will need to have the following items:
+
To perform this procedure, the following items are required:
  
−
* The Compact Flash card you wish to use to hold the firmware.
+
* The Compact Flash card to hold the firmware.
−
* A Compact Flash card reader attached to your computer.
+
* A Compact Flash card reader attached to a computer.
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* The firmware image.
+
* The filesystem tar.
 
* A fully functional Linux desktop.
 
* A fully functional Linux desktop.
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* The package management tools installed: <code>tar</code>, and either <code>gzip</code> or <code>bzip2</code> (depending on the image).
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* Linux tools installed: <code>tar</code>, and either <code>gzip</code> or <code>bzip2</code> (depending on the image).
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* The EMAC package which provides the <code>put-image</code> script.  The <code>README.TXT</code> file in the package details out the steps needed to install the script properly.
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* The EMAC [ftp://ftp.emacinc.com/EMAC_Linux/SDK/Archive/Linux/put-image.tar.gz put-image] package which provides the <code>put-image</code> script.  The <code>README.TXT</code> file in the package details the steps needed to install the script properly.
  
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The <code>put-image</code> script, and its associated tools, can be downloaded from [https://svn.emacinc.com/listing.php?repname=EMAC+Public+Repository&path=%2FEMAC-OE-2009.03-STABLE%2Ftrunk%2Fcontrib%2Fput-image%2F&rev=0&sc=0| EMAC's Subversion Repository].
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Unpack the put-image tar after downloading:
  
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The script and its tools can be downloaded, if you have ''svn'' (Subversion) installed, by running the following command in a terminal:
 
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
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svn co https://svn.emacinc.com/public/EMAC-OE-2009.03-STABLE/trunk/contrib/put-image/
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developer@ldc:~$ tar zxvf ~/Downloads/put-image.tar.gz
 
</syntaxhighlight>
 
</syntaxhighlight>
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When you run the above command, you should see something like this:
+
 
−
<syntaxhighlight lang="bash">developer@ldc:~$ svn co https://svn.emacinc.com/public/EMAC-OE-2009.03-STABLE/trunk/contrib/put-image/
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{{mbox | type=warning | text= '''WARNING''': Performing the following procedure incorrectly can cause a catastrophic loss of data.  The individual steps should be carefully studied prior to attempting the procedure for the first time.<br /><br /> EMAC cannot be responsible for the loss of data which may result from following this procedure incorrectly. EMAC strongly recommends having a current backup of the data on the development computer before attempting this procedure.}}
−
</syntaxhighlight><syntaxhighlight lang="console">
 
−
A    put-image/date2stamp
 
−
A    put-image/stamp2date
 
−
A    put-image/datediff
 
−
A    put-image/put-image
 
−
A    put-image/lilo-22.8.sbin.static.tgz
 
−
A    put-image/README.TXT
 
−
Checked out revision 175.
 
−
</syntaxhighlight><syntaxhighlight lang="bash">developer@ldc:~$</syntaxhighlight>
 
−
<br />
 
−
{{mbox | type=warning | text= '''WARNING''': Performing the following procedure incorrectly can cause a catastrophic loss of data.  The individual steps should be carefully studied prior to attempting the procedure for the first time.<br /><br /> EMAC cannot be responsible for the loss of data which may result from incorrectly following this procedure. EMAC strongly recommends having a current backup of the data on your computer before attempting this procedure.  Use it at your own risk.}}
 
  
 
==Procedure==
 
==Procedure==
  
−
Perform the following steps to load the firmware onto your Compact Flash card:
+
Perform the following steps to load the firmware onto the Compact Flash card:
 +
 
 +
* Insert the Compact Flash card into the card reader.
 +
* Navigate (from within the shell) to the directory which contains the firmware image to be used.
 +
* Determine where the Compact Flash card was mounted.
  
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* Insert the Compact Flash card into your card reader.
 
−
* Navigate (from within the shell) to the directory which contains the firmware image you wish to use.
 
−
* Determine where the Compact Flash card was mounted:
 
 
<syntaxhighlight lang="console">
 
<syntaxhighlight lang="console">
 
developer@ldc:~$ dmesg | tail -n 10
 
developer@ldc:~$ dmesg | tail -n 10
Line 49: Line 42:
 
[23243.787314] sd 12:0:0:0: [sdc] No Caching mode page present
 
[23243.787314] sd 12:0:0:0: [sdc] No Caching mode page present
 
[23243.787326] sd 12:0:0:0: [sdc] Assuming drive cache: write through
 
[23243.787326] sd 12:0:0:0: [sdc] Assuming drive cache: write through
−
[23243.790625]  sdc: sdc1[23244.290093] kjournald starting.  Commit interval 5 seconds
+
[23243.790625]  sdc: sdc1
 +
[23244.290093] kjournald starting.  Commit interval 5 seconds
 
[23244.293646] EXT3-fs (sdc1): using internal journal
 
[23244.293646] EXT3-fs (sdc1): using internal journal
 
[23244.293651] EXT3-fs (sdc1): mounted filesystem with ordered data mode
 
[23244.293651] EXT3-fs (sdc1): mounted filesystem with ordered data mode
Line 55: Line 49:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
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'''xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'''
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The output of the <code>dmesg</code> command shows that the root device node for the Compact Flash card in this case is <code>sdc</code>, and that the only partition found is <code>sdc1</code>.  Inspect the output shown above to see the particular device node on the development PC where the Compact Flash card is mounted. This will be different depending on the configuration of the development PC. The <code>/dev/</code> prefix will go before the device name, but is not shown in the output of <code>dmesg</code>. The device node will start with either <code>sd</code> or <code>hd</code>.  The third letter will specify which of these devices is assigned to the CF card.
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The output of the <code>dmesg</code> command tells us that the Compact Flash card, in this case, was mounted on <code>/dev/sdc1</code>, and that its device node is <code>/dev/sdc</code>.  '''NO, the preceding sentence is incorrect.''' Inspect the output shown above to see where this information came from. The <code>/dev/</code> prefix will go before the device name, but is not shown in the output. The letters you are looking to see will start with either <code>sd</code> or <code>hd</code>.  The third letter will specify which of these devices is assigned to the CF Card.
+
 
−
* At this point, it is wise to double check to ensure you have the correct device node for the Compact Flash card. Specifying the wrong device node could cause a complete loss of data on your hard drive.  It is very important to be extremely careful when specifying the device node for the Compact Flash.<br /><br /> Continuing with <code>/dev/sdc1</code> as our example device node, type the following command:
+
* At this point, it is wise to double check that device node is actually the CF card and not a hard drive in the system. Specifying the wrong device node could cause a complete loss of data on a hard drive.  <br /><br /> Continuing with <code>/dev/sdc1</code> as the example device node, type the following command:
  
 
<syntaxhighlight lang="console">
 
<syntaxhighlight lang="console">
Line 64: Line 58:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
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This shows us that the device node, <code>/dev/sdc1</code>, is in fact our Compact Flash card.  We know this because:
+
This shows that the device node, <code>/dev/sdc1</code>, is in fact the Compact Flash card.  This is because:
 
* It is not mounted on one of the standard Linux filesystem mountpoints, such as <code>/</code>, <code>/boot</code>, <code>/usr</code>, or <code>/home</code>.
 
* It is not mounted on one of the standard Linux filesystem mountpoints, such as <code>/</code>, <code>/boot</code>, <code>/usr</code>, or <code>/home</code>.
−
* It '''is''' mounted in the <code>/media</code> directory, where we expect it.  We may alternatively expect to see it mounted in <code>/mnt</code>, depending upon the configuration of the Linux distribution in use.
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* It '''is''' mounted in the <code>/media</code> directory, where it is expected.  It may alternatively get mounted in <code>/mnt</code>, depending upon the configuration of the Linux distribution in use.
  
−
<br />{{mbox | type=notice | text='''NOTE''': Not all Linux distributions will have <code>automount</code> enabled.  If <code>automount</code> is not enabled, the device will not automatically be mounted when it is inserted into a card reader.<br /><br /> For those unfamiliar with the term <code>mount</code>, <code>mount</code>ing a device means the operating system associates one or more file paths with the filesystem(s) contained within the partition(s) of the <code>mount</code>ed device.}}<br />
+
{{mbox | type=notice | text='''NOTE''': Not all Linux distributions will automatically mount the CF card when it is inserted into the card reader. The CF card must first be mounted in order to be accessible to the operating system. See [http://www.gnu.org/software/libc/manual/html_node/Mount_002dUnmount_002dRemount.html http://www.gnu.org/software/libc/manual/html_node/Mount_002dUnmount_002dRemount.html] for more information about mounting filesystems.}}
  
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* Use <code>fdisk -l</code> to inspect the device node:
+
* Use <code>fdisk -l</code> to inspect the device node. Use <code>sudo</code> with <code>fdisk</code> to gain the required <code>root</code> privileges to run <code>fdisk</code>
  
 
<syntaxhighlight lang="console">
 
<syntaxhighlight lang="console">
Line 86: Line 80:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
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{{mbox | type=info | text='''NOTE''': The <code>sudo</code> command is needed to run the <code>fdisk</code> command as <code>root</code>.  If you are running as the <code>root</code> user, then you will not need to use the <code>sudo</code> command.}}
+
* As can be seen from the output of the <code>fdisk -l</code> command above, the disk is 4009 MB in size, which corresponds with the size of the 4 GB Compact Flash being used in this example.
−
<br />
+
 
−
{{mbox | type= | image=none | text='''TIP''': As can be seen from the output of the <code>fdisk -l</code> command above, the disk is 4009 MB in size, which corresponds with the size of the 4 GB Compact Flash being used in this example.}}
+
* The device to specify for the target boot argument must also be determined prior to installing the image onto the Compact Flash card. Images obtained from EMAC will contain a text file that specifies what boot device node to use. For a custom image, use the <code>fdisk -l</code> command on the target device to determine the boot device. In this example, the target hardware specifies ''/dev/hdc'' for the boot device.
  
 +
* Now, run the ''put-image'' script as below.
 +
** The --target option specifies where the card is mounted.
 +
** The --boot option specifies the target boot argument.
 +
** The last option is the file name of the compressed target root filesystem.
  
−
* The device to specify for the boot argument must also be determined prior to putting the image onto the Compact Flash card.  If you downloaded the firmware image from EMAC, there should be a text file associated with the image which tells you which device to specify for this.  If you have built your own custom image, you should use the same boot device as you used with firmware from EMAC.  In this example, we're using hardware which specifies ''/dev/hdc'' for the boot device.
+
After completion, the ''put-image'' script will output a message indicating success or failure.
−
* Now, run the ''put-image'' script:
 
  
−
<syntaxhighlight lang="bash">
+
<syntaxhighlight lang="console">
−
developer@ldc:~$ /path/to/put-image --root=/dev/sdc --boot=/dev/hdc emac-firmware-image.tar.gz
+
developer@ldc:~$ /path/to/put-image --target=/dev/sdc --boot=/dev/sda emac-firmware-image.tar.gz
 +
</syntaxhighlight>
 +
 
 +
* The ''put-image'' script should automatically unmount the Compact Flash card after the process completes. It is best to check that the Compact Flash card is actually unmounted before unplugging it. Using the ''/dev/sdc1'' example from above, type the following command.
 +
<syntaxhighlight lang="console">
 +
developer@ldc:~$ mount | grep sdc1
 +
</syntaxhighlight>
 +
 
 +
* If the command does not return anything, the Compact Flash card is not mounted and can be removed and inserted into the target device. However, if the command returns something similar to the following listing, the card will need to be unmounted manually.
 +
 
 +
<syntaxhighlight lang="console">
 +
/dev/sdc1 on /media/EMAC-OE type ext3 (rw,nosuid,nodev,uhelper=udisks)
 +
</syntaxhighlight>
 +
 
 +
* To unmount the Compact Flash card manually, run the following command:
 +
<syntaxhighlight lang="console">
 +
developer@ldc:~$ umount /dev/sdc1
 
</syntaxhighlight>
 
</syntaxhighlight>
  

Latest revision as of 14:33, 5 March 2018

When changing firmware images or creating custom firmware images for your Compact Flash-based machine, it is necessary to perform a few steps to load the firmware image onto the CF card.

Necessary Tools

To perform this procedure, the following items are required:

  • The Compact Flash card to hold the firmware.
  • A Compact Flash card reader attached to a computer.
  • The filesystem tar.
  • A fully functional Linux desktop.
  • Linux tools installed: tar, and either gzip or bzip2 (depending on the image).
  • The EMAC put-image package which provides the put-image script. The README.TXT file in the package details the steps needed to install the script properly.

Unpack the put-image tar after downloading: 

developer@ldc:~$ tar zxvf ~/Downloads/put-image.tar.gz
WARNING: Performing the following procedure incorrectly can cause a catastrophic loss of data. The individual steps should be carefully studied prior to attempting the procedure for the first time.

EMAC cannot be responsible for the loss of data which may result from following this procedure incorrectly. EMAC strongly recommends having a current backup of the data on the development computer before attempting this procedure.

Procedure

Perform the following steps to load the firmware onto the Compact Flash card:

  • Insert the Compact Flash card into the card reader.
  • Navigate (from within the shell) to the directory which contains the firmware image to be used.
  • Determine where the Compact Flash card was mounted.
developer@ldc:~$ dmesg | tail -n 10
[23236.042944] sdc: detected capacity change from 4110188544 to 0
[23243.783467] sd 12:0:0:0: [sdc] 8027712 512-byte logical blocks: (4.11 GB/3.82 GiB)
[23243.785199] sd 12:0:0:0: [sdc] No Caching mode page present
[23243.785204] sd 12:0:0:0: [sdc] Assuming drive cache: write through
[23243.787314] sd 12:0:0:0: [sdc] No Caching mode page present
[23243.787326] sd 12:0:0:0: [sdc] Assuming drive cache: write through
[23243.790625]  sdc: sdc1
[23244.290093] kjournald starting.  Commit interval 5 seconds
[23244.293646] EXT3-fs (sdc1): using internal journal
[23244.293651] EXT3-fs (sdc1): mounted filesystem with ordered data mode
developer@ldc:~$

The output of the dmesg command shows that the root device node for the Compact Flash card in this case is sdc, and that the only partition found is sdc1. Inspect the output shown above to see the particular device node on the development PC where the Compact Flash card is mounted. This will be different depending on the configuration of the development PC. The /dev/ prefix will go before the device name, but is not shown in the output of dmesg. The device node will start with either sd or hd. The third letter will specify which of these devices is assigned to the CF card.

  • At this point, it is wise to double check that device node is actually the CF card and not a hard drive in the system. Specifying the wrong device node could cause a complete loss of data on a hard drive.

    Continuing with /dev/sdc1 as the example device node, type the following command:
developer@ldc:~$ mount | grep sdc1
/dev/sdc1 on /media/EMAC-OE type ext3 (rw,nosuid,nodev,uhelper=udisks)

This shows that the device node, /dev/sdc1, is in fact the Compact Flash card. This is because:

  • It is not mounted on one of the standard Linux filesystem mountpoints, such as /, /boot, /usr, or /home.
  • It is mounted in the /media directory, where it is expected. It may alternatively get mounted in /mnt, depending upon the configuration of the Linux distribution in use.
NOTE: Not all Linux distributions will automatically mount the CF card when it is inserted into the card reader. The CF card must first be mounted in order to be accessible to the operating system. See http://www.gnu.org/software/libc/manual/html_node/Mount_002dUnmount_002dRemount.html for more information about mounting filesystems.
  • Use fdisk -l to inspect the device node. Use sudo with fdisk to gain the required root privileges to run fdisk
developer@ldc:~$ sudo fdisk -l /dev/sdc
Disk /dev/sdc: 4009 MB, 4009549824 bytes
77 heads, 56 sectors/track, 1816 cylinders, total 7831152 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00090707 
  
 Device Boot      Start         End      Blocks   Id  System
/dev/sdc1              62     7831151     3915545   83  Linux
developer@ldc:~$
  • As can be seen from the output of the fdisk -l command above, the disk is 4009 MB in size, which corresponds with the size of the 4 GB Compact Flash being used in this example.
  • The device to specify for the target boot argument must also be determined prior to installing the image onto the Compact Flash card. Images obtained from EMAC will contain a text file that specifies what boot device node to use. For a custom image, use the fdisk -l command on the target device to determine the boot device. In this example, the target hardware specifies /dev/hdc for the boot device.
  • Now, run the put-image script as below.
    • The --target option specifies where the card is mounted.
    • The --boot option specifies the target boot argument.
    • The last option is the file name of the compressed target root filesystem.

After completion, the put-image script will output a message indicating success or failure. 

developer@ldc:~$ /path/to/put-image --target=/dev/sdc --boot=/dev/sda emac-firmware-image.tar.gz
  • The put-image script should automatically unmount the Compact Flash card after the process completes. It is best to check that the Compact Flash card is actually unmounted before unplugging it. Using the /dev/sdc1 example from above, type the following command.
developer@ldc:~$ mount | grep sdc1
  • If the command does not return anything, the Compact Flash card is not mounted and can be removed and inserted into the target device. However, if the command returns something similar to the following listing, the card will need to be unmounted manually.
/dev/sdc1 on /media/EMAC-OE type ext3 (rw,nosuid,nodev,uhelper=udisks)
  • To unmount the Compact Flash card manually, run the following command:
developer@ldc:~$ umount /dev/sdc1

See Also

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