Yocto tests

About

• All of the described things happen in Kubuntu 13.04
• Building Linux images for Zynq platform - ARMv7

Required packages

src link:

sudo apt-get install gawk wget git-core diffstat unzip texinfo build-essential chrpath

sudo apt-get install libsdl1.2-dev xterm

sudo apt-get install make xsltproc docbook-utils fop dblatex xmlto

sudo apt-get install autoconf automake libtool libglib2.0-dev

Output targets

Output folder: poky/build/tmp/deploy/images

These names are as they appear in the u-boot configuration header file - actual output files have different names:

• boot.bin - u-boot as the first stage bootloader
• devicetree.dtb - device tree with described interfaces, zynq registers, interrupts and drivers
• uImage - kernel, drivers
• uramdisk.image.gz - applications

Copy them on the micro SD card > run boot once in the u-boot command line.

Setup

• Step 1:

git clone -b dora git://git.yoctoproject.org/poky.git
cd poky # (just for convenience)
git clone git://git.code.sf.net/p/elphel/meta-elphel393 meta-elphel393
git clone git://git.code.sf.net/p/elphel/meta-ezynq meta-ezynq
git clone -b dora https://github.com/openembedded/meta-oe.git
git clone -b dora https://github.com/Xilinx/meta-xilinx.git

• Step 2: Init environment

cd poky
. ./oe-init-build-env

• Step 3: Edit build/conf/bblayers.conf - add paths to BBLAYERS:

<absolute-path>/poky/meta-elphel393 \
<absolute-path>/poky/meta-ezynq \
<absolute-path>/poky/meta-oe/meta-oe \
<absolute-path>/poky/meta-oe/meta-webserver \
<absolute-path>/poky/meta-oe/meta-networking \
<absolute-path>/poky/meta-xilinx \

• Step 4: Edit build/conf/local.conf - set MACHINE and other things:

 BB_NUMBER_THREADS = "8" (depends on the PC's CPU)
 PARALLEL_MAKE = "-j 8" (depends on the PC's CPU)
 MACHINE ?= "elphel393" (based on MACHINE="zedboard" )

Notes

• Currently having 4 MACHINES: elphel393, microzed, zc706 and zedboard

Build bootloader

bitbake u-boot-ezynq
or
bitbake u-boot
or
bitbake virtual/bootloader

Output

• poky/build/tmp/deploy/images/boot.bin

Notes

Build kernel

bitbake linux-xlnx
or
bitbake virtual/kernel

Output

• poky/build/tmp/deploy/images/uImage (kernel)
• poky/build/tmp/deploy/images/devicetree.dtb (or some *.dtb)

Notes

• Sources are cloned to:

poky/build/tmp/work/MACHINE-poky-linux-gnueabi/linux-xlnx/.../linux

• If you change files like debug drivers for example, when done editing run:

bitbake linux-xlnx -c compile
bitbake linux-xlnx -c deploy

Build ramdisk.image.gz

bitbake core-image-elphel393

Output

• poky/build/tmp/deploy/images/uramdisk.image.gz (the file has *.u-boot extension after it's built)

Notes

elphel393.bb:
IMAGE_INSTALL = "packagegroup-core-boot python-core ${ROOTFS_PKGMANAGE_BOOTSTRAP} ${CORE_IMAGE_EXTRA_INSTALL}"

elphel393.bb:
IMAGE_INSTALL = "packagegroup-core-boot ${ROOTFS_PKGMANAGE_BOOTSTRAP} ${CORE_IMAGE_EXTRA_INSTALL}"
IMAGE_INSTALL_append = "python-core"

IMAGE_INSTALL_append = "<mandatory space?>python-core \
                       i2c-tools \
                       mtd-utils \
                       net-tools \
                       openssh \
                       modphp \
                       apache2 \
                       php-cli"

meta-oe/meta-oe/recipes-devtools/php/php.inc:
PACKAGES = "${PN}-dbg ${PN}-cli ${PN}-cgi ${PN}-fpm ${PN}-fpm-apache2 ${PN}-pear ${PN}-dev ${PN}-staticdev ${PN}-doc ${PN}"

U-boot and device tree related notes

• The default UNPACKED ramdisk max size for zynq is 16MB - once it gets bigger you get KERNEL PANIC - the solution is modifying the device tree - then recompile into DTB:

*.dts, add to bootargs parameter ramdisk_size=32768 (takes KB), example:
bootargs = "console=ttyPS0,115200 root=/dev/ram rw ip=192.168.1.10 earlyprintk ramdisk_size=65536";

• The default COMPRESSED ramdisk max size for zynq is 10MB set in u-boot - change according to your needs, example:

zynq_zed.h:
"sdboot=echo Copying Linux from SD to RAM... && " \
               "mmcinfo && " \
               "fatload mmc 0 0x3000000 ${kernel_image} && " \
               "fatload mmc 0 0x2A00000 ${devicetree_image} && " \
               "fatload mmc 0 0x2000000 ${ramdisk_image} && " \
               "bootm 0x3000000 0x2000000 0x2A00000\0" \

So, the max sizes:
compressed ramdisk    = 0x2A00000 - 0x2000000 = 0xA00000 = 10MB
devicetree = 0x3000000 - 0x2A00000 = 0x600000 = 6MB

Build everything all together

bitbake ezynq-u-boot linux-xlnx core-image-elphel393

Build toolchain (not necessary - needed only for building ezynq targets outside poky)

• Step 1: build

bitbake meta-toolchain

• Step 2: install - launch installer from <some-path>/poky/build/tmp/deploy/

Apply a patch from a recipe

• Example file tree (meta-elphel393):

meta-elphel393/
    recipes-kernel/
        linux/
            linux-xlnx_3.8.bb
            linux-xlnx.inc
            linux-xlnx/
                elphel393_defconfig_3.8.cfg
                elphel393.dts
                xilinx_nandps.patch

• Goal: apply a patch to linux-xlnx files
• Step 1:

bitbake linux-xlnx

• Step 2: Go to where the linux-xlnx got cloned - find and edit the target file:

poky/build/tmp/work/elphel393-poky-linux-gnueabi/linux-xlnx/.../linux/

• Step 3: In the mentioned above directory run:

git diff > somefile.patch

• Step 4: Copy the patch file into recipes/kernel/linux/linux-xlnx/.
• Step 5: Edit the recipe, here it's linux-xlnx.inc, add a line like the following:

Apply the patch when building for any MACHINE:

SRC_URI_append += "file://xilinx_nandps.patch"

SRC_URI_append_elphel393 += "file://xilinx_nandps.patch"

• Step 6(?):

bitbake linux-xlnx -c clean -f
bitbake linux-xlnx

Create *.bbappend for an existing package in meta-*

• Define FILESEXTRAPATHS_prepend := "${THISDIR}/files:" for files that come with the bbappend - so the fetcher could find them
• Try to add "_append" & "_prepend" to functions
• If some do_function is incompatible just rewrite it

Switch to dora branch

cd poky; git checkout dora
cd meta-oe; git checkout dora
cd meta-elphel393; git checkout master

Branching in git

git checkout <name>

git checkout -b <new-branch> <existing-branch>

git branch -D <name>

git push origin <name>

git push origin :<name>

Disappeared errors

• • (Is there a better solution for kubuntu 13.04? in kubuntu 12.10 there is no such error - or is it just newer version?) To fix the ERROR="Could not inherit file classes/vala.bbclass" in bitbake copy vala.bbclass from oe-core? or delete the conflicting recipes (2?)?
  • (Is there a better solution for kubuntu 13.04? in kubuntu 12.10 there is no such error - or is it just newer version?) To fix the ERROR="Failed to parse krb5_1.11.3.bb" in bitbake delete the directory meta-oe/meta-oe/recipes-connectivity/krb5

RTC config example in DTS

http://www.denx.de/wiki/DULG/Appendix

Program bitstream from Linux

cat /sys/devices/amba.0/f8007000.ps7-dev-cfg/prog_done

cat test.bit > /dev/xdevcfg

Create and set up an own external mirror in Yocto/OpenEmbedded

SOURCE_MIRROR_URL = "file:///data/sources/"
INHERIT += "own-mirrors" 
BB_GENERATE_MIRROR_TARBALLS = "1"

It didn't store anything in /data/sources/, but in the build/downloads/ instead - tar.gz + tar.gz's made from cloned git repositories.

MIRRORS =+ "http://.*/.*     http://mirror.elphel.com/elphel393_mirror/ \n "

#SOURCE_MIRROR_URL = "file:///data/sources/"
#INHERIT += "own-mirrors" 
#BB_GENERATE_MIRROR_TARBALLS = "1"