[oe] OE builds LKMs not matching kernel version (MACHINE="dm6446-evm")

[Bjørn Forsman]

2009/12/9 Bjørn Forsman <bjorn.forsman at gmail.com>:
> Hi all,
>
> I'm using MACHINE="dm6446-evm" and DISTRO="angstrom-2008.1" and OE
> builds different/incompatible versions of the kernel modules (LKM) and
> the kernel. How do I go about debugging this?
>
> The built images seem correct on the host (same version number):
>
> uImage-2.6.31+2.6.32-rc2-r28+gitr7b2683fd0168df1576fcea947ef9f63e905de807-r28-dm6446-evm.bin
> modules-2.6.31+2.6.32-rc2-r28+gitr7b2683fd0168df1576fcea947ef9f63e905de807-r28-dm6446-evm.tgz
>
> But when booting the target, the kernel complains because the LKMs
> doesn't match the kernel version:
> ----
> WARNING: Couldn't open directory
> /lib/modules/2.6.32-rc2-09211-g17d857b: No such file or directory
> FATAL: Could not open
> /lib/modules/2.6.32-rc2-09211-g17d857b/modules.dep.temp for writing:
> No such file or directory
> WARNING: Couldn't open directory
> /lib/modules/2.6.32-rc2-09211-g17d857b: No such file or directory
> FATAL: Could not open
> /lib/modules/2.6.32-rc2-09211-g17d857b/modules.dep.temp for writing:
> No such file or directory
> ...snip...
> # ls -l /lib/modules
> drwxr-xr-x    3 root     root         4096 Dec  9 00:10 2.6.32-rc2-davinci1
> # insmod /lib/modules/2.6.32-rc2-davinci1/kernel/fs/smbfs/smbfs.ko
> [  264.580000] smbfs: disagrees about version of symbol module_layout
> insmod: cannot insert
> '/lib/modules/2.6.32-rc2-davinci1/kernel/fs/smbfs/smbfs.ko': invalid
> module format
> # uname -r
> 2.6.32-rc2-09211-g17d857b
> ----
>
> I really wish I knew OE well enough to debug this myself, but I don't
> (yet). What is the bitbake target for kernel modules? Where is is the
> decision on what kernel version to build the LKMs against? How is it
> possible for LKMs to end up being built for wrong kernels?
>
> (I have tried to generate a dependency graph with 'bitbake -g
> base-image', hoping that it would give me some clues. But my machine
> just hangs for a long time and then segfaults when trying to view
> depends.dot.)
>
> Best regards,
> Bjørn Forsman
>

This is embarrassing: there is no problem with OE, it was just that I had
not copied the correct uImage to /tftpboot. Sorry for the noise.

Best regards,
Bjørn Forsman