diff options
Diffstat (limited to 'usermanual/reference/image_types.xml')
| -rw-r--r-- | usermanual/reference/image_types.xml | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/usermanual/reference/image_types.xml b/usermanual/reference/image_types.xml index 68058bec3e..2efb9b8072 100644 --- a/usermanual/reference/image_types.xml +++ b/usermanual/reference/image_types.xml @@ -5,7 +5,7 @@ <para>One of the most commonly used outputs from a build is a filesystem image containing the root filesystem for the target device. There are several variables which can be used to control the type of output images and - the settings for those images such as endianess or compression ratios. This + the settings for those images, such as endianess or compression ratios. This section details the available images and the variables that effect them. See the <xref linkend="image_ipkg_class" /> section for details on how image generation is configured.</para> @@ -186,6 +186,8 @@ rmdir ${DEPLOY_DIR_IMAGE}/tmp.gz"</screen></para> big and little endian filesystems can be mounted on any platform.</para> + <para>Squashfs uses gzip as its compression method.</para> + <para><screen>IMAGE_CMD_squashfs = "mksquashfs ${IMAGE_ROOTFS} \ ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.squashfs \ ${EXTRA_IMAGECMD} -noappend"</screen></para> @@ -199,6 +201,33 @@ rmdir ${DEPLOY_DIR_IMAGE}/tmp.gz"</screen></para> </varlistentry> <varlistentry> + <term>squashfs-lzma</term> + + <listitem> + <para>Creates a squashfs image using lzma compression instead of + gzip which is the standard squashfs compression type. This is a read + only compressed filesystem which is used directly with files + uncompressed into RAM as they are accessed. Files and filesystems + may be up to 2^64 bytes in size, full 32-bit uids and gids are + stored, it detects duplicate files and stores only a single copy, + all meta-data is compressed and big and little endian filesystems + can be mounted on any platform.</para> + + <para>Squashfs-lzma uses lzma as its compression method.</para> + + <para><screen>IMAGE_CMD_squashfs-lzma = "mksquashfs-lzma ${IMAGE_ROOTFS} \ + ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.squashfs \ + ${EXTRA_IMAGECMD} -noappend"</screen></para> + + <para>The <command>EXTRA_IMAGECMD</command> variable for squashfs is + passed to <command>mksquashfs-lzma</command> and by default is used + specify the endianess and block size of the filesystem:</para> + + <para><screen>EXTRA_IMAGECMD_squashfs-lzma = "-le -b 16384"</screen></para> + </listitem> + </varlistentry> + + <varlistentry> <term>tar</term> <listitem> @@ -261,7 +290,9 @@ rmdir ${DEPLOY_DIR_IMAGE}/tmp.gz"</screen></para> <para>An example can be found in <command>conf/machine/wrt54.conf</command> where it defines a new image type, <emphasis>squashfs-lzma</emphasis>, for a squashfs filesystem using - lzma compression instead of the standard gzip compression:<screen>IMAGE_DEPENDS_squashfs-lzma = "squashfs-tools-native" + lzma compression instead of the standard gzip compression (squashfs-lzma + is now a standard type, but the example still serves to show the + concept):<screen>IMAGE_DEPENDS_squashfs-lzma = "squashfs-tools-native" IMAGE_CMD_squashfs-lzma = "mksquashfs-lzma ${IMAGE_ROOTFS} \ ${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.squashfs-lzma \ ${EXTRA_IMAGECMD} -noappend" |