HowToIncreaseSizeOfRamdisk < DULG

%SECTION0{name=SELFHotToIncreaseRamdiskSize}% How to Increase the Size of the Ramdisk

   1 Extract compressed ramdisk image (ramdisk.gz) from U-Boot image:
      <verbatim>
bash$ dd if=uRamdisk bs=64 skip=1 of=ramdisk.gz
21876+1 records in
21876+1 records out
      </verbatim>
   1 Uncompress ramdisk image
      <verbatim>
bash$ gunzip -v ramdisk.gz
ramdisk.gz:      66.6% -- replaced with ramdisk
      </verbatim>
   1 Mount ramdisk image
   <br>As root:
      <verbatim>
bash# mkdir -p /mnt/tmp
bash# mount -o loop ramdisk /mnt/tmp
      </verbatim>
   1 Create new ramdisk image, say 8 <nop>MB big:
      <verbatim>
bash$ dd if=/dev/zero of=new_ramdisk bs=1024k count=8
bash$ /sbin/mke2fs -F -m0 new_ramdisk
bash$ /sbin/tune2fs -c 0 -i 0 new_ramdisk
      </verbatim>
   As root:
      <verbatim>
bash# mkdir -p /mnt/new
bash# mount -o loop new_ramdisk /mnt/new
      </verbatim>
   1 Copy files from old ramdisk to new ramdisk:
   <br>As root:
      <verbatim>
bash# cd /mnt/tmp
bash# find . -depth -print | cpio -VBpdum /mnt/new
      </verbatim>
   Now you can add, remove, or modify files in the /mnt/new
   directory. If you are done, you can re-pack the ramdisk into a
   U-Boot image:
   1 Unmount ramdisk images:
   <br>As root:
      <verbatim>
bash# umount /mnt/tmp
bash# umount /mnt/new
      </verbatim>
   1 Compress new ramdisk image
      <verbatim>
bash$ gzip -v9 new_ramdisk
ramdisk:         66.6% -- replaced with new_ramdisk.gz
      </verbatim>
   1 Create new U-Boot image (new-uRamdisk)
      <verbatim>
bash$ mkimage -T ramdisk -C gzip -n 'New Simple Embedded Linux Framework' \
> -d new_ramdisk.gz new_uRamdisk
Image Name:   Simple Embedded Linux Framework
Created:      Sun May  4 13:23:48 2003
Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
Data Size:    1400121 Bytes = 1367.31 kB = 1.34 MB
Load Address: 0x00000000
Entry Point:  0x00000000
      </verbatim>

%T% Remember that Linux by default supports only ramdisks up to a size of 4 MB.
For bigger ramdisks,
you have to either modify your LInux kernel configuration
(parameter =CONFIG_BLK_DEV_RAM_SIZE= in the "Block devices" menue),
or pass a ="ramdisk_size="= boot argument to the Linux kernel.
14.4.1. How to Add Files to a SELF Ramdisk		1. Abstract		14.5. RTAI
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