Difference between revisions of "DevKit8600 FAQ"

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Line 7: Line 7:
  
 
  #cd ramdisk.gz
 
  #cd ramdisk.gz
 
 
  #gunzip ramdisk.gz
 
  #gunzip ramdisk.gz
  
Line 13: Line 12:
  
 
  #mkdir /mnt/loop
 
  #mkdir /mnt/loop
 
 
  #mount –o loop ramdisk /mnt/loop
 
  #mount –o loop ramdisk /mnt/loop
 
 
  #cd /mnt/loop
 
  #cd /mnt/loop
  
Line 21: Line 18:
  
 
3. Unmount the image file;
 
3. Unmount the image file;
 
+
  /#cd ramdisk
+
  #cd ramdisk
 
 
 
  #umount /mnt/loop
 
  #umount /mnt/loop
  
Line 30: Line 26:
 
  #gzip –v9 ramdisk
 
  #gzip –v9 ramdisk
  
Q2: How to create a new Root File System?
+
'''Q2: How to create a new Root File System?
 
+
(Approach one)'''
(Approach one)
 
  
 
1. Create a temporary mounting point for loop devices;
 
1. Create a temporary mounting point for loop devices;
  
#mkdir /mnt/loop
+
#mkdir /mnt/loop
  
 
2. Create a 15M temporary file;
 
2. Create a 15M temporary file;
  
#dd if=/dev/zero of=/tmp/loop_tmp bs=1k count=15360
+
#dd if=/dev/zero of=/tmp/loop_tmp bs=1k count=15360
  
 
The size of the temporary file could be changed by adjusting the value of the parameter count;
 
The size of the temporary file could be changed by adjusting the value of the parameter count;
Line 46: Line 41:
 
3. Associate device file with the temporary file;
 
3. Associate device file with the temporary file;
  
#losetup /dev/loop0 /tmp/loop_tmp  
+
#losetup /dev/loop0 /tmp/loop_tmp  
  
 
If a message ‘ioctl:LOOP_SET_FD: device is busy’ appears, it indicates that the device /dev/loop0 is still associated with another file. Command losetup /dev/loop0 can be used to view the device, and remove it with parameter -d;
 
If a message ‘ioctl:LOOP_SET_FD: device is busy’ appears, it indicates that the device /dev/loop0 is still associated with another file. Command losetup /dev/loop0 can be used to view the device, and remove it with parameter -d;
Line 52: Line 47:
 
4. Format /dev/loop0 as ext2 file system;
 
4. Format /dev/loop0 as ext2 file system;
  
#mke2fs –m 0 /dev/loop0
+
#mke2fs –m 0 /dev/loop0
  
 
5. Mount the virtual disk on the mounting point /mnt/loop;
 
5. Mount the virtual disk on the mounting point /mnt/loop;
  
#mount –t ext2 /dev/loop0 /mnt/loop;
+
#mount –t ext2 /dev/loop0 /mnt/loop;
  
 
6. Copy all the required files to the virtual disk by the command cp -af;
 
6. Copy all the required files to the virtual disk by the command cp -af;
Line 62: Line 57:
 
7. Move from current directory /mnt/loop to another directory by the command cd, and then unmount the file system;
 
7. Move from current directory /mnt/loop to another directory by the command cd, and then unmount the file system;
  
#cd /xx (xx means any directories except /mnt/loop)
+
#cd /xx (xx means any directories except /mnt/loop)
  
#umount /mnt/loop  
+
#umount /mnt/loop  
  
 
The file at /tmp/loop_tmp is the image of file system.
 
The file at /tmp/loop_tmp is the image of file system.
Line 70: Line 65:
 
8. Compress the image file to create a file system;
 
8. Compress the image file to create a file system;
  
#gzip –v9 /tmp/loop_tmp >/tftpboot/ramdisk.gz  
+
#gzip –v9 /tmp/loop_tmp >/tftpboot/ramdisk.gz  
  
 
or  
 
or  
#gzip –v9 /tmp/loop_tmp  
+
#gzip –v9 /tmp/loop_tmp  
 
 
(Approach two)
 
  
 +
'''(Approach two)'''
 
1. Create a temporary mounting point for loop devices;
 
1. Create a temporary mounting point for loop devices;
  
#mkdir /mnt/loop
+
#mkdir /mnt/loop

Latest revision as of 02:31, 6 November 2012

Q1: How to alter an existing Root File System?

Let’s assume there is a compressed file system named ramdisk.gz. We could realize alteration on it by the following steps:

1. Uncompress the file into an image file;

#cd ramdisk.gz
#gunzip ramdisk.gz

2. Mount the uncompressed image file to realize alteration;

#mkdir /mnt/loop
#mount –o loop ramdisk /mnt/loop
#cd /mnt/loop

Now the contents of the file system can be added, removed, or modified as required.

3. Unmount the image file;

#cd ramdisk
#umount /mnt/loop

4. Create a compressed file by using the altered file system;

#gzip –v9 ramdisk

Q2: How to create a new Root File System? (Approach one)

1. Create a temporary mounting point for loop devices;

#mkdir /mnt/loop

2. Create a 15M temporary file;

#dd if=/dev/zero of=/tmp/loop_tmp bs=1k count=15360

The size of the temporary file could be changed by adjusting the value of the parameter count;

3. Associate device file with the temporary file;

#losetup /dev/loop0 /tmp/loop_tmp 

If a message ‘ioctl:LOOP_SET_FD: device is busy’ appears, it indicates that the device /dev/loop0 is still associated with another file. Command losetup /dev/loop0 can be used to view the device, and remove it with parameter -d;

4. Format /dev/loop0 as ext2 file system;

#mke2fs –m 0 /dev/loop0

5. Mount the virtual disk on the mounting point /mnt/loop;

#mount –t ext2 /dev/loop0 /mnt/loop;

6. Copy all the required files to the virtual disk by the command cp -af;

7. Move from current directory /mnt/loop to another directory by the command cd, and then unmount the file system;

#cd /xx (xx means any directories except /mnt/loop)
#umount /mnt/loop 

The file at /tmp/loop_tmp is the image of file system.

8. Compress the image file to create a file system;

#gzip –v9 /tmp/loop_tmp >/tftpboot/ramdisk.gz 

or

#gzip –v9 /tmp/loop_tmp 

(Approach two) 1. Create a temporary mounting point for loop devices;

#mkdir /mnt/loop