Netboot image creation for SPARC machines - Revision history

217.81.155.39: /* Preparing a ramdisk image */

2013-05-15T05:47:40Z

‎Preparing a ramdisk image

Palica: /* Strategy suggestion */

2012-11-18T09:17:57Z

‎Strategy suggestion

24.201.209.90: /* Preparing a ramdisk image */

2012-01-29T23:23:16Z

‎Preparing a ramdisk image

404 Error: /* Putting the kernel modules and firmware images inside the initramfs image */

2012-01-29T02:06:37Z

‎Putting the kernel modules and firmware images inside the initramfs image

404 Error: /* Preparing a ramdisk image */

2012-01-29T02:06:20Z

‎Preparing a ramdisk image

404 Error at 02:02, 29 January 2012

2012-01-29T02:02:28Z

404 Error at 01:56, 29 January 2012

2012-01-29T01:56:42Z

Show changes

404 Error: /* Creating the initramfs image */

2012-01-28T18:05:37Z

‎Creating the initramfs image

404 Error: /* Mandatory shared object files coming from /lib */

2011-02-23T14:06:07Z

‎Mandatory shared object files coming from /lib

404 Error: /* Limitations */

2011-02-23T14:05:21Z

‎Limitations

@@ Line 61: / Line 61: @@
 == Preparing a ramdisk image ==
-You have to strategies for the initramfs image. You can either create it from:
+You have two strategies for the initramfs image. You can either create it from:
 # A cpio archive of a live filesystem (so far we didn't succeed in producing a usable compressed cpio archive, the kernel panics on boot)

← Older revision		Revision as of 09:17, 18 November 2012
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	[[Category:HOWTO]]		[[Category:HOWTO]]
		+	[[Category:SPARC]]

← Older revision		Revision as of 23:23, 29 January 2012
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	Although it not mandatory required to copy those two files, it will, however help BusyBox' mdev.		Although it not mandatory required to copy those two files, it will, however help BusyBox' mdev.
		+
		+	=== Populating /dev ===
		+
		+	You have two ways to populate /dev:
		+
		+	# Let the kernel manages everything for you (devtmpfs): A temporary tmpfs containing special devices entries are created very early at system start up and are then moved in the /dev directory once the root filesystem has been mounted.
		+	# Manually create some entries in what will be included with the ramdisk and let mdev so the rest when the netboot image has been booted.
		+
		+	For the first alternative, just enable '''Maintain a devtmpfs filesystem to mount at /dev''' and ''Automount devtmpfs at /dev, after the kernel mounted the rootfs'' (see ''Device drivers / Generic Devices Options'') in your kernel configuration. For the second alternative, just use mknod to create some basic devices which are:
		+
		+	<pre>
		+
		+	</pre>
		+

	=== Mandatory shared object files coming from /lib ===		=== Mandatory shared object files coming from /lib ===

@@ Line 166: / Line 166: @@
 The backslash and the 2 lines form of the command line is present only for the sake of clarity, you can put everything on a single (long) line.
-=== Putting the kernel modules and firmware images inside the initramfs image ===
+=== Putting the kernel modules and firmware images inside the ramdisk image ===
 {{fancywarning|You will need to pass though this section even your kernel has no support for modules because some device drivers in the kernel need a firmware image (this is the case with Broadcom Tigeon 3 network adapters or QLogic Fibre Channel HBA for example).}}
@@ Line 176: / Line 176: @@
 linux # make modules_install INSTALL_MOD_PATH=/mnt/netboot-rootfs
 </pre>
 === Adding extra mandatory libs ===

@@ Line 74: / Line 74: @@
 # losetup /usr/src/root.img /dev/loop0
 # mkfs.ext2 /dev/loop0
-# mkdir /mnt/netboot-initramfs
+# mkdir /mnt/netboot-rootfs
-# mount /dev/loop0 /mnt/netboot-initramfs
+# mount /dev/loop0 /mnt/netboot-rootfs
 </pre>
 === Structure creation ===
-First, you need to create a bare minimal file system structure in a working directory of you choice, although '''/mnt/netboot-initramfs''' is used here, anything left at of your choice can be used. You will need :
+First, you need to create a bare minimal file system structure in a working directory of you choice, although '''/mnt/netboot-rootfs''' is used here, anything left at of your choice can be used. You will need :
 * /bin
@@ Line 93: / Line 93: @@
 <pre>
-# cd /mnt/netboot-initramfs
+# cd /mnt/netboot-rootfs
-/mnt/netboot-initramfs # mkdir -p bin dev dev/pts etc sbin usr/bin usr/sbin tmp
+netboot-rootfs # mkdir -p bin dev dev/pts etc sbin usr/bin usr/sbin tmp
 </pre>
@@ Line 100: / Line 100: @@
 <pre>
-/mnt/netboot-initramfs # cp /etc/passwd /etc/group etc
+netboot-rootfs # cp /etc/passwd /etc/group etc
 </pre>
@@ Line 128: / Line 128: @@
 <pre>
-/mnt/netboot-initramfs # cd /lib
+netboot-rootfs # cd /lib
-lib # cp libc-2.11.2.so libc-2.11.2.so ld-2.11.2.so ld-linux.so.2 libblkid.so.1.1.0 ..... /mnt/netboot-initramfs/lib
+lib # cp libc-2.11.2.so libc-2.11.2.so ld-2.11.2.so ld-linux.so.2 libblkid.so.1.1.0 ..... /mnt/netboot-rootfs/lib
 </pre>
@@ Line 153: / Line 153: @@
 <pre>
 # CFLAGS="-mcpu=v9 -O2 -pipe" FEATURES="nodoc noinfo noman" USE="-pam make-symlinks mdev savedconfig" \
-emerge -1 --root=/mnt/netboot-initramfs sys-apps/busybox
+emerge -1 --root=/mnt/netboot-rootfs sys-apps/busybox
 </pre>
@@ Line 160: / Line 160: @@
 * Not deploy any manpages, infopages or any kind of docuementation (see /usr/share) etc.
 * Not use PAM (netboot environment is  single administrative user only)
-* Make symlinks for enabled BusyBox applets in the '''bin''' and '''sbin''' subdirectories of /mnt/netboot-initramfs (BusyBox is a multicall binary)
+* Make symlinks for enabled BusyBox applets in the '''bin''' and '''sbin''' subdirectories of /mnt/netboot-rootfs (BusyBox is a multicall binary)
-* Use /mnt/netboot-initramfs as the root directory for the deployment
+* Use /mnt/netboot-rootfs as the root directory for the deployment
-* Not register sys-apps/busybox in the world file of the Funtoo "mini-instance" located under /mnt/netboot-initramfs /mnt/netboot-initramfs/var/lib/portage/world)
+* Not register sys-apps/busybox in the world file of the Funtoo "mini-instance" located under /mnt/netboot-rootfs /mnt/netboot-rootfs/var/lib/portage/world)
 The backslash and the 2 lines form of the command line is present only for the sake of clarity, you can put everything on a single (long) line.
@@ Line 174: / Line 174: @@
 <pre>
 # cd /usr/src/linux
-linux # make modules_install INSTALL_MOD_PATH=/mnt/netboot-initramfs
+linux # make modules_install INSTALL_MOD_PATH=/mnt/netboot-rootfs
 </pre>
@@ Line 198: / Line 198: @@
 <pre>
 # cd /usr/src
-src # umount /mnt/netboot-initramfs
+src # umount /mnt/netboot-rootfs
 src # xz --check=none --lzma2=dict=1MiB root.img
 src # mv root.img.xz root.img

← Older revision		Revision as of 02:02, 29 January 2012
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	That's it!		That's it!
		+
		+	At system start-up pay attention to :
		+
		+	<pre>
		+	....
		+	[ 81.921360] Trying to unpack rootfs image as initramfs...
		+	[ 81.922859] rootfs image is not initramfs (no cpio magic); looks like an initrd
		+	[ 81.943133] Freeing initrd memory: 3846k freed
		+	...
		+	[ 103.079351] RAMDISK: xz image found at block 0
		+	[ 107.384859] VFS: Mounted root (ext2 filesystem) on device 1:0.
		+	....
		+	</pre>

	= Strategy suggestion =		= Strategy suggestion =

@@ Line 179: / Line 179: @@
 <pre>
 tmp # cd initramfs-image
-initramfs-image # cpio * > ../root.img
+initramfs-image # find . | cpio -o > ../root.img
 tmp # xz --check=none --lzma2=dict=1MiB root.img
 tmp # cp root.img.xz /usr/src/root.img

@@ Line 103: / Line 103: @@
 * libc.so.6 (symlink to libc-2.11.2.so)
 * libcom_err.so.2.1
-* libcom_err.so.2 -> libcom_err.so.2.1
+* libcom_err.so.2 (symlink to libcom_err.so.2.1)
 * libcrypt.so.1
 * libe2p.so.2

@@ Line 30: / Line 30: @@
 * sun4u machines (e.g. UltraSPARC I/II/III/IV servers and workstations) do not initialize the processor MMU and thus, '''this ''requires'' the whole netboot image to fit within 4 megabytes'''. What happens if this rule is enforced?  Simple: as the buffer where the netboot image is loaded into acts as a 4 megabytes ring-buffer, any byte exceeding the limit will overwrite the previously netboot image loaded data leading to the so famous "Fast Data Access MMU Miss" a couple of seconds after the machine started to download the netboot image.
-* sun4v machines (e.g. UltraSPARC T1 and later) initialize their MMU and thus, are not subject to the above limitation. Pay attention to the startup messages when you power on the machine you will see something like "Init MMU init" (assuming you are connected to the virtual console from ALOM):
+* sun4v machines (e.g. UltraSPARC T1 and later) initialize their MMU and thus, are not subject to the above limitation. Pay attention to the startup messages when you power on the machine you will see something like "Init MMU" (assuming you are connected to the virtual console from ALOM):
 <pre>