FreeRunner backup kernel - Revision history

Kempelen: Category: +Flashing Openmoko

2008-09-15T22:27:52Z

Category: +Flashing Openmoko

DolfjeBot1: Replacing 'Freerunner' with 'FreeRunner'

2008-08-31T12:34:19Z

Replacing 'Freerunner' with 'FreeRunner'

DolfjeBot1: Freerunner backup kernel moved to FreeRunner backup kernel: Replacing 'Freerunner' with 'FreeRunner'

2008-08-31T12:21:00Z

Freerunner backup kernel moved to FreeRunner backup kernel: Replacing 'Freerunner' with 'FreeRunner'

Glenn: +cat

2008-08-09T13:38:59Z

+cat

Warmcat: New page: == Freerunner backup kernel == The Freerunner NAND partition for the monolithic kernel is set to be 8MBytes, but currently kernels are around 2MBytes in size. This allows us to stash a s...

2008-08-07T08:14:14Z

New page: == Freerunner backup kernel == The Freerunner NAND partition for the monolithic kernel is set to be 8MBytes, but currently kernels are around 2MBytes in size. This allows us to stash a s...

New page

== Freerunner backup kernel ==

The Freerunner NAND partition for the monolithic kernel is set to be 8MBytes, but currently kernels are around 2MBytes in size. This allows us to stash a second, backup kernel in that partition for use in an emergency. If your USB network connection is unavailable was knocked out for some reason, or the modules in the rootfs are bad and crash on every boot, this can be highly useful to have alongside DFU as a boot menu option eventually.

[[Image:Recovery-kernel.png]]

Since this was only implemented after production, factory Freerunners do not currently have a recovery kernel, but it's possible to add as described here.

Once you installed the recovery kernel, it won't get overwritten by subsequent DFU kernel updates because DFU only erases as far as it writes, which is no more than 2MBytes for normal kernel update.

=== Current packaging compatability issue ===
<blockquote>Right this second the packaged kernels erase the whole partition on update, but I am requesting that be changed so they won't touch the backup kernel either.</blockquote>

== Installing the backup kernel ==

Recovery kernels are "moredrivers" kernels that include the critical drivers in the main kernel already. Additionally, because they share a partition with the normal kernel, they are around 6MB in size to get the recovery part at the 4MB offset as shown in the picture above.

You can get a 6MB recovery image from here: [http://warmcat.com/recovery-uImage-moredrivers-stable_507c3c1ba3921bb7.bin 6M recovery kernel image]

Just DFU it in normally to the kernel partition. When the issue about packaged erase is fixed, subsequent updates by DFU or kernel package will update the first kernel normally, but leave the backup one at +4MBytes alone.

== Selecting the backup kernel in U-Boot ==

This one-liner at the U-Boot prompt will boot you into the backup kernel. (FIXME: integrate into boot menu to make all this actually useful)

<blockquote>setenv bootcmd nand read.e 0x32000000 kernel \; setenv bootargs \${mtdparts} rootfstype=jffs2 root=/dev/mtdblock6 console=tty0 console=ttySAC2,115200 loglevel=3 init=/sbin/init \; bootm 0x32400000 ; boot</blockquote>

← Older revision		Revision as of 22:27, 15 September 2008
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	[[Category:Kernel]]		[[Category:Kernel]]
		+	[[Category:Flashing Openmoko]]

← Older revision		Revision as of 13:38, 9 August 2008
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	<blockquote>setenv bootcmd nand read.e 0x32000000 kernel \; setenv bootargs \${mtdparts} rootfstype=jffs2 root=/dev/mtdblock6 console=tty0 console=ttySAC2,115200 loglevel=3 init=/sbin/init \; bootm 0x32400000 ; boot</blockquote>		<blockquote>setenv bootcmd nand read.e 0x32000000 kernel \; setenv bootargs \${mtdparts} rootfstype=jffs2 root=/dev/mtdblock6 console=tty0 console=ttySAC2,115200 loglevel=3 init=/sbin/init \; bootm 0x32400000 ; boot</blockquote>
		+
		+	[[Category:Kernel]]

@@ Line 1: / Line 1: @@
-== Freerunner backup kernel ==
+== FreeRunner backup kernel ==
-The Freerunner NAND partition for the monolithic kernel is set to be 8MBytes, but currently kernels are around 2MBytes in size.  This allows us to stash a second, backup kernel in that partition for use in an emergency.  If your USB network connection is unavailable was knocked out for some reason, or the modules in the rootfs are bad and crash on every boot, this can be highly useful to have alongside DFU as a boot menu option eventually.
+The FreeRunner NAND partition for the monolithic kernel is set to be 8MBytes, but currently kernels are around 2MBytes in size.  This allows us to stash a second, backup kernel in that partition for use in an emergency.  If your USB network connection is unavailable was knocked out for some reason, or the modules in the rootfs are bad and crash on every boot, this can be highly useful to have alongside DFU as a boot menu option eventually.
 [[Image:Recovery-kernel.png]]
-Since this was only implemented after production, factory Freerunners do not currently have a recovery kernel, but it's possible to add as described here.
+Since this was only implemented after production, factory FreeRunners do not currently have a recovery kernel, but it's possible to add as described here.
 Once you installed the recovery kernel, it won't get overwritten by subsequent DFU kernel updates because DFU only erases as far as it writes, which is no more than 2MBytes for normal kernel update.