diff options
author | Scott Rifenbark <srifenbark@gmail.com> | 2016-12-29 10:26:15 -0800 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2017-01-11 17:23:10 +0000 |
commit | 1e51b7173aab728386b8ea1c78f17a53d065b36d (patch) | |
tree | b073bb8219a8aec25f85c9009ac25fe9accb20ac /documentation/ref-manual/ref-variables.xml | |
parent | 5068f2c960877f21aee76eb26322b7977acc0fc3 (diff) | |
download | openembedded-core-contrib-1e51b7173aab728386b8ea1c78f17a53d065b36d.tar.gz |
dev-manual, ref-manual: Created new section on initramfs
Fixes [YOCTO #7096]
We did not document how to create an initramfs image to be included
with a kernel build. Various variables sort of inferred the
knowledge. I created a new section in the "Common Tasks" section
of the dev-manual that describes how to create an initramfs image.
Also, I updated the kernel.bbclass reference section to point back
to the new "how-to" section.
Finally, I also created a bunch of cross-reference links from various
related variables back to the new "how-to" section.
(From yocto-docs rev: a14e550494641c46ac2518632cbf251e07d459fd)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/ref-manual/ref-variables.xml')
-rw-r--r-- | documentation/ref-manual/ref-variables.xml | 50 |
1 files changed, 35 insertions, 15 deletions
diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml index 0f6535cea1..a696ee4e66 100644 --- a/documentation/ref-manual/ref-variables.xml +++ b/documentation/ref-manual/ref-variables.xml @@ -2273,12 +2273,13 @@ <glossentry id='var-CONFIG_INITRAMFS_SOURCE'><glossterm>CONFIG_INITRAMFS_SOURCE</glossterm> <info> - CONFIG_INITRAMFS_SOURCE[doc] = "Identifies the initial RAM disk (initramfs) source files. The OpenEmbedded build system receives and uses this kernel Kconfig variable as an environment variable." + CONFIG_INITRAMFS_SOURCE[doc] = "Identifies the initial RAM filesystem (initramfs) source files. The OpenEmbedded build system receives and uses this kernel Kconfig variable as an environment variable." </info> <glossdef> <para role="glossdeffirst"> <!-- <para role="glossdeffirst"><imagedata fileref="figures/define-generic.png" /> --> - Identifies the initial RAM disk (initramfs) source files. + Identifies the initial RAM filesystem (initramfs) source + files. The OpenEmbedded build system receives and uses this kernel Kconfig variable as an environment variable. By default, the variable is set to null (""). @@ -2304,6 +2305,12 @@ If you specify multiple directories and files, the initramfs image will be the aggregate of all of them. </para> + + <para> + For information on creating an initramfs, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#building-an-initramfs-image'>Building an Initial RAM Filesystem (initramfs) Image</ulink>" + section in the Yocto Project Development Manual. + </para> </glossdef> </glossentry> @@ -5405,9 +5412,12 @@ variable to specify packages for installation. Instead, use the <link linkend='var-PACKAGE_INSTALL'><filename>PACKAGE_INSTALL</filename></link> - variable, which allows the initial RAM disk (initramfs) - recipe to use a fixed set of packages and not be - affected by <filename>IMAGE_INSTALL</filename>. + variable, which allows the initial RAM filesystem + (initramfs) recipe to use a fixed set of packages and + not be affected by <filename>IMAGE_INSTALL</filename>. + For information on creating an initramfs, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#building-an-initramfs-image'>Building an Initial RAM Filesystem (initramfs) Image</ulink>" + section in the Yocto Project Development Manual. </note> </para> @@ -6133,13 +6143,13 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" <glossentry id='var-INITRAMFS_FSTYPES'><glossterm>INITRAMFS_FSTYPES</glossterm> <info> - INITRAMFS_FSTYPES[doc] = "Defines the format for the output image of an initial RAM disk (initramfs), which is used during boot." + INITRAMFS_FSTYPES[doc] = "Defines the format for the output image of an initial RAM filesystem (initramfs), which is used during boot." </info> <glossdef> <para role="glossdeffirst"> <!-- <para role="glossdeffirst"><imagedata fileref="figures/define-generic.png" /> --> Defines the format for the output image of an initial - RAM disk (initramfs), which is used during boot. + RAM filesystem (initramfs), which is used during boot. Supported formats are the same as those supported by the <link linkend='var-IMAGE_FSTYPES'><filename>IMAGE_FSTYPES</filename></link> variable. @@ -6152,7 +6162,7 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>, is "cpio.gz". The Linux kernel's initramfs mechanism, as opposed to the - initial RAM disk + initial RAM filesystem <ulink url='https://en.wikipedia.org/wiki/Initrd'>initrd</ulink> mechanism, expects an optionally compressed cpio archive. @@ -6162,7 +6172,7 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" <glossentry id='var-INITRAMFS_IMAGE'><glossterm>INITRAMFS_IMAGE</glossterm> <info> - INITRAMFS_IMAGE[doc] = "Specifies the PROVIDES name of an image recipe that is used to build an initial RAM disk (initramfs) image." + INITRAMFS_IMAGE[doc] = "Specifies the PROVIDES name of an image recipe that is used to build an initial RAM filesystem (initramfs) image." </info> <glossdef> <para role="glossdeffirst"> @@ -6170,7 +6180,7 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" Specifies the <link linkend='var-PROVIDES'><filename>PROVIDES</filename></link> name of an image recipe that is used to build an initial - RAM disk (initramfs) image. + RAM filesystem (initramfs) image. An initramfs provides a temporary root filesystem used for early system initialization (e.g. loading of modules needed to locate and mount the "real" root filesystem). @@ -6211,17 +6221,21 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" </para> <para> - Finally, for more information you can also see the + For more information, you can also see the <link linkend='var-INITRAMFS_IMAGE_BUNDLE'><filename>INITRAMFS_IMAGE_BUNDLE</filename></link> variable, which allows the generated image to be bundled inside the kernel image. + Additionally, for information on creating an initramfs, see + the + "<ulink url='&YOCTO_DOCS_DEV_URL;#building-an-initramfs-image'>Building an Initial RAM Filesystem (initramfs) Image</ulink>" + section in the Yocto Project Development Manual. </para> </glossdef> </glossentry> <glossentry id='var-INITRAMFS_IMAGE_BUNDLE'><glossterm>INITRAMFS_IMAGE_BUNDLE</glossterm> <info> - INITRAMFS_IMAGE_BUNDLE[doc] = "Controls whether or not the image recipe specified by INITRAMFS_IMAGE is run through an extra pass (do_bundle_initramfs) during kernel compilation in order to build a single binary that contains both the kernel image and the initial RAM disk (initramfs)." + INITRAMFS_IMAGE_BUNDLE[doc] = "Controls whether or not the image recipe specified by INITRAMFS_IMAGE is run through an extra pass (do_bundle_initramfs) during kernel compilation in order to build a single binary that contains both the kernel image and the initial RAM filesystem (initramfs)." </info> <glossdef> <para role="glossdeffirst"> @@ -6231,8 +6245,8 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" is run through an extra pass (<link linkend='ref-tasks-bundle_initramfs'><filename>do_bundle_initramfs</filename></link>) during kernel compilation in order to build a single binary - that contains both the kernel image and the initial RAM disk - (initramfs). + that contains both the kernel image and the initial RAM + filesystem (initramfs) image. This makes use of the <link linkend='var-CONFIG_INITRAMFS_SOURCE'><filename>CONFIG_INITRAMFS_SOURCE</filename></link> kernel feature. @@ -6279,6 +6293,9 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" See the <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta-poky/conf/local.conf.sample.extended'><filename>local.conf.sample.extended</filename></ulink> file for additional information. + Also, for information on creating an initramfs, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#building-an-initramfs-image'>Building an Initial RAM Filesystem (initramfs) Image</ulink>" + section in the Yocto Project Development Manual. </para> </glossdef> </glossentry> @@ -9105,9 +9122,12 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" the <link linkend='images-core-image-minimal-initramfs'><filename>core-image-minimal-initramfs</filename></link> image. - When working with an initial RAM disk (initramfs) + When working with an initial RAM filesystem (initramfs) image, use the <filename>PACKAGE_INSTALL</filename> variable. + For information on creating an initramfs, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#building-an-initramfs-image'>Building an Initial RAM Filesystem (initramfs) Image</ulink>" + section in the Yocto Project Development Manual. </para> </glossdef> </glossentry> |