[yocto] custom linux kernel recipe

Tue Aug 30 08:09:05 PDT 2016

On 2016-08-30 07:33 AM, Mircea Gliga wrote:
> Thanks for your answer Bruce !
>
> I've applied the patch you've mentioned
> (http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/commit/?h=zedd/kernel&id=0fe665e69983fe9ef38319deedcb78ecd7b165cf)
> to my recipe, linux-stable_4.7.bb, providing the dtb:
>
> KERNEL_DEVICETREE_qemuarm = "versatile-pb.dtb"
> QEMU_DTB_qemuarm = "zImage-versatile-pb"
>
> I've also updated my runqemu-internal script to add the dtb file to the
> qemu options.
> For some reason the QEMU_DTB variable is empty so I hard coded the dtb
> filename just to make a test.

I actually had that in the wrong place. I've since removed the variable
from the kernel recipes. Sorry about that :D

>
> So now, when running the qemuarm machine, the dtb file is provided with
> the "dtb" parameter.
> The result is the same, a black screen.
> As mentioned, my recipe is using the 4.7.2 kernel: the Latest Stable Kernel
>
> Then I applied the patch to the linux-yocto-dev.bb recipe (I'm on
> krogoth) - this is using kernel 4.8
> This boots correctly - without the dtb patch the result is the same:
> black screen.
>
> But I'm stuck with the 4.7.2 kernel - the Latest Stable Kernel, any
> suggestions on how to accomplish this ? It looks like the patch is not
> enough for kernel 4.7.2.

I'm finishing up 4.8 today, but without doing a boot test, I can't say
for sure. I'll see if I can cycle in some korg 4.7.x testing tomorrow to
see if I can get a clean boot.

Bruce

>
> Thanks in advance.
> Mircea
>
> On 08/29/2016 04:02 PM, Bruce Ashfield wrote:
>> On 2016-08-29 07:34 AM, Mircea Gliga wrote:
>>> Hi
>>>
>>> I'm using krogoth and trying to create a qemu arm machine with the
>>> latest stable kernel 4.7.2.
>>> I created a recipe,recipes-kernel/linux/linux-stable_4.7.bb, in my layer
>>> with the following contents:
>>>
>>> ---
>>> inherit kernel
>>> require recipes-kernel/linux/linux-yocto.inc
>>>
>>> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}-${PV}:"
>>>
>>> KBRANCH ?= "linux-4.7.y"
>>>
>>> SRCREV ?= "84fae3f89282ce86a0c0da30e35fe66dbcadda6f"
>>>
>>> KBRANCH_sama5d4-xplained ?= "linux-4.7.y"
>>> SRCREV_machine_sama5d4-xplained ?=
>>> "84fae3f89282ce86a0c0da30e35fe66dbcadda6f"
>>>
>>> KERNEL_DEVICETREE_sama5d4-xplained = "at91-sama5d4_xplained.dtb"
>>>
>>> KBRANCH_qemuarm ?= "linux-4.7.y"
>>>
>>> SRC_URI =
>>> "git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git;bareclone=1;branch=${KBRANCH}"
>>>
>>>
>>>
>>> SRC_URI += "file://defconfig"
>>>
>>> LINUX_VERSION = "4.7.2"
>>> PV = "${LINUX_VERSION}+git${SRCPV}"
>>>
>>> COMPATIBLE_MACHINE = "sama5d4-xplained|qemuarm"
>>> ---
>>>
>>> As you can see, I'm planning to use this recipe for multiple machines.
>>>
>>> In the recipes-kernel/linux/linux-stable-4.7/qemuarm/ directory I copied
>>> the defconfig file.
>>> I've created this defconfig file by:
>>> * sourcing my build environment, from my build directory: source
>>> build-qemu/tmp/environment-setup-armv5e-poky-linux-gnueabi
>>> * running "make vexpress_defconfig" in the kernel build directory. (I've
>>> used this tutorial
>>> https://balau82.wordpress.com/2012/03/31/compile-linux-kernel-3-2-for-arm-and-emulate-with-qemu/
>>>
>>> )
>>> This outputed:
>>>
>>> ---
>>> $ make vexpress_defconfig
>>>   GEN     ./Makefile
>>> #
>>> # configuration written to .config
>>> #
>>> ---
>>>
>>> * renamed .config to defconfig and then copy it in
>>> recipes-kernel/linux/linux-stable-4.7/qemuarm/
>>>
>>> In my local.conf I've added, in order to use my custom kernel for the
>>> qemu machine:
>>>
>>> ---
>>> MACHINE ??= "qemuarm"
>>> PREFERRED_PROVIDER_virtual/kernel_qemuarm ?= "linux-stable"
>>> ---
>>>
>>> Everything builds without errors (bitbake linux-stable), but when I
>>> start qemu (runqemu qemuarm) I only get a black screen in the QEMU
>>> window.
>>> This is the output of $ runqemu qemuarm:
>>> ---
>>> Continuing with the following parameters:
>>> KERNEL:
>>> [/home/user/yocto-k/build-qemu/tmp/deploy/images/qemuarm/zImage-qemuarm.bin]
>>>
>>>
>>> ROOTFS:
>>> [/home/user/yocto-k/build-qemu/tmp/deploy/images/qemuarm/custom-minimal-image-qemuarm-20160823102657.rootfs.ext4]
>>>
>>>
>>> FSTYPE: [ext4]
>>> Setting up tap interface under sudo
>>> [sudo] password for user:
>>> Acquiring lockfile for tap0...
>>> Running qemu-system-arm...
>>> /home/user/yocto-k/build-qemu/tmp/sysroots/x86_64-linux/usr/bin/qemu-system-arm
>>>
>>> -kernel
>>> /home/user/yocto-k/build-qemu/tmp/deploy/images/qemuarm/zImage-qemuarm.bin
>>>
>>> -net nic,model=virtio -net
>>> tap,vlan=0,ifname=tap0,script=no,downscript=no -M versatilepb -drive
>>> file=/home/user/yocto-k/build-qemu/tmp/deploy/images/qemuarm/custom-minimal-image-qemuarm-20160823102657.rootfs.ext4,if=virtio,format=raw
>>>
>>> -no-reboot -show-cursor -usb -usbdevice tablet -no-reboot -m 128 -serial
>>> mon:vc -serial null -append "root=/dev/vda rw console=ttyAMA0,115200
>>> console=tty ip=192.168.7.2::192.168.7.1:255.255.255.0 mem=128M
>>> highres=off rootfstype=ext4 "
>>> ---
>>>
>>> This is my build configuration:
>>> Build Configuration:
>>> BB_VERSION        = "1.30.0"
>>> BUILD_SYS         = "x86_64-linux"
>>> NATIVELSBSTRING   = "universal"
>>> TARGET_SYS        = "arm-poky-linux-gnueabi"
>>> MACHINE           = "qemuarm"
>>> DISTRO            = "poky"
>>> DISTRO_VERSION    = "2.1.1"
>>> TUNE_FEATURES     = "arm armv5 thumb dsp"
>>> TARGET_FPU        = "soft"
>>> meta
>>> meta-poky
>>> meta-yocto-bsp    = "krogoth:12eb72ee3b02f826a156ff4e396c770f2b93571e"
>>> meta-smartcom     = "master:121dbfb9f416de8442bbad1dc150271fd50b38e6"
>>> meta-atmel        = "krogoth:01ff01073dd8fa1463b7841fb0a8caa44559acdd"
>>> meta-oe
>>> meta-networking
>>> meta-python       = "krogoth:247b1267bbe95719cd4877d2d3cfbaf2a2f4865a"
>>>
>>>
>>> When I use the default linux-yocto as the preferred kernel (v 4.4)
>>> everything works as expected.
>>> Do you have any suggestions? Is there a problem with the defconfig file
>>> provided ?
>>> What is the proper way of creating this defconfig file for qemuarm ?
>>> I also tried using the .config file created when building
>>> linux-yocto_4.4 but got the same result.
>>> I tried the defconfig used for the
>>
>> You need a variant of the patch I'm going to submit later today:
>>
>> http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/commit/?h=zedd/kernel&id=0fe665e69983fe9ef38319deedcb78ecd7b165cf
>>
>>
>> I'm about to bump linux-yocto to 4.8, which ran into the device tree
>> changes for the versatile/vexpress class boards. You are seeing the
>> same thing.
>>
>>
>> Bruce
>>
>>
>>>
>>> Thanks !
>>>
>>
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