[yocto] Build external module against Yocto kernel

[Patrick Turley]

On Jan 22, 2013, at 2:34 PM, Bruce Ashfield <bruce.ashfield at windriver.com> wrote:
> On 13-01-22 03:28 PM, Patrick Turley wrote:
>> One problem I ran into … When I tried to execute "make scripts," I got a whole bunch of config questions that I *think* should have been answered with a .config file or something. Should I have copied out the .config file from the kernel work directory into the SDK installation before I ran that? Is that the "best" way to get around all the questions?
>> 
> 
> Interesting. I haven't seen this myself, so just a couple of quick
> questions:
> 
>  - without the .config, did you still get a working set of hostprogs, and
>    only had to suffer the warnings ?
> 
>  - If the answer is yes, then the .config really doesn't matter for this
>    and the approach of grabbing a .config should work fine or even
>    having a dummy defconfig available with enough to keep the build
>    happy.
> 
> Definitely sounds like something we can address and it's worth putting into
> bugzilla so it doesn't get lost.

Below, please find a transcript of the commands I executed.

You'll see that I installed the SDK, tried to "make scripts," and then got attacked with a storm of config questions. I cut off the transcript at the second question, but there are dozens that follow.

There *is* a .config file in the SDK directory, and it is identical to the one in our kernel build directory:

/home/pturley/yocto-mpu-build/tmp/work/dm8148_mpu-poky-linux-gnueabi/linux-ti81xx-psp-2.6.37-r0+spawnlabs+r0/git

Unfortunately, I'm still something of a n00b when it comes to building the kernel. I suspect *most* of these questions are irrelevant to hostprogs, but I can't say that *all* of them are.

If I just hold down the "Enter" key, I believe all the defaults are taken, and I eventually *do* get hostprogs that execute, but I don't know if they're appropriate to my kernel. (Again, I'm a n00b, so perhaps there's no effect at all.)

--------------------

$ pwd
/home/pturley/yocto-mpu-build/tmp/deploy/sdk

$ ls
poky-eglibc-x86_64-arm-toolchain-1.3.sh

$ sudo ./poky-eglibc-x86_64-arm-toolchain-1.3.sh 
Enter target directory for SDK (default: /opt/poky/1.3): 
You are about to install the SDK to "/opt/poky/1.3". Proceed[Y/n]?
Extracting SDK...done
Setting it up...done
SDK has been successfully set up and is ready to be used.

$ cd /opt/poky/1.3/sysroots/dm8148_mpu-poky-linux-gnueabi/usr/src/kernel

$ ls -a
.              firmware           lib             scripts
..             fs                 MAINTAINERS     security
arch           include            Makefile        sound
block          init               mm              System.map-2.6.37
.config        ipc                Module.symvers  tools
COPYING        Kbuild             net             uImage
CREDITS        Kconfig            patches         usr
crypto         kernel             README          virt
Documentation  kernel-abiversion  REPORTING-BUGS
drivers        kernel-image-name  samples

$ sudo make scripts
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/basic/docproc
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/kxgettext.o
  SHIPPED scripts/kconfig/zconf.tab.c
  SHIPPED scripts/kconfig/lex.zconf.c
  SHIPPED scripts/kconfig/zconf.hash.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
scripts/kconfig/conf --silentoldconfig Kconfig
*
* Restart config...
*
*
* General setup
*
Prompt for development and/or incomplete code/drivers (EXPERIMENTAL) [Y/n/?] y
Cross-compiler tool prefix (CROSS_COMPILE) [] 
Local version - append to kernel release (LOCALVERSION) [] 
Automatically append version information to the version string (LOCALVERSION_AUTO) [N/y/?] n
Kernel compression mode
> 1. Gzip (KERNEL_GZIP)
  2. Bzip2 (KERNEL_BZIP2) (NEW)
  3. LZMA (KERNEL_LZMA)
  4. LZO (KERNEL_LZO)
choice[1-4?]: 
Support for paging of anonymous memory (swap) (SWAP) [N/y/?] n
System V IPC (SYSVIPC) [Y/n/?] y
POSIX Message Queues (POSIX_MQUEUE) [Y/n/?] y
BSD Process Accounting (BSD_PROCESS_ACCT) [Y/n/?] y
  BSD Process Accounting version 3 file format (BSD_PROCESS_ACCT_V3) [Y/n/?] y
Export task/process statistics through netlink (EXPERIMENTAL) (TASKSTATS) [Y/n/?] y
  Enable per-task delay accounting (EXPERIMENTAL) (TASK_DELAY_ACCT) [Y/n/?] y
  Enable extended accounting over taskstats (EXPERIMENTAL) (TASK_XACCT) [Y/n/?] y
    Enable per-task storage I/O accounting (EXPERIMENTAL) (TASK_IO_ACCOUNTING) [Y/n/?] y
Auditing support (AUDIT) [N/y/?] n
Kernel .config support (IKCONFIG) [Y/n/m/?] y
  Enable access to .config through /proc/config.gz (IKCONFIG_PROC) [Y/n/?] y
Kernel log buffer size (16 => 64KB, 17 => 128KB) (LOG_BUF_SHIFT) [17] 17
enable deprecated sysfs features to support old userspace tools (SYSFS_DEPRECATED) [N/y/?] n
Kernel->user space relay support (formerly relayfs) (RELAY) [N/y/?] n
Initial RAM filesystem and RAM disk (initramfs/initrd) support (BLK_DEV_INITRD) [Y/n/?] y
  Initramfs source file(s) (INITRAMFS_SOURCE) [] 
Optimize for size (CC_OPTIMIZE_FOR_SIZE) [Y/n/?] y
Disable heap randomization (COMPAT_BRK) [Y/n/?] y
Choose SLAB allocator
  1. SLAB (SLAB)
> 2. SLUB (Unqueued Allocator) (SLUB)
choice[1-2?]: 2
Profiling support (PROFILING) [Y/n/?] y
OProfile system profiling (OPROFILE) [M/n/y/?] m
  OProfile multiplexing support (EXPERIMENTAL) (OPROFILE_EVENT_MULTIPLEX) [N/y/?] (NEW)