Advanced OpenEmbedded

Setting up opkg feeds

Install Apache
- sudo apt-get install apache2
Add a symlink to the openembedded deploy/ipk directory:
- sudo ln -s /home/user/chumby-oe/output-angstrom-.9/deploy/eglibc/ipk /var/www/oe-repo
Determine your IP address, and then add the following line to meta-chumby/conf/local.conf - you will need to rebuild the -image and re-write it to an SD card:
- FEED_DEPLOYDIR_BASE_URI = "http://ip-address/oe-repo"
After you finish building packages, refresh the package index
- bitbake package-index
On the device, re-fetch the package list
- opkg update
On the device, search for packages or install them
- opkg list '*strace*'
- opkg install strace

Edit meta-chumby/conf/local.conf
- nano -w meta-chumby/conf/local.conf
Change "BB_NUMBER_THREADS" to be something reasonable such as one greater than the number of cores present on your system.
Change PARALLEL_MAKE to be 1 or 2, depending on how much memory you have.
If you're running builds under X11, remove the "TERMCMD" and "TERMCMDRUN" commands. If you ever need to use the devshell under X11, it will open up a new xterm. The default is to open up a new "screen" session, which is best for interacting with OpenEmbedded via SSH.
Save and quit
- Press Ctrl-X, type "Y", and press Enter to save and quit.

Edit meta-chumby/conf/machine/chumby-falconwing.conf
- nano -w meta-chumby/conf/machine/chumby-falconwing.conf
Change the size of the rootfs. Value is in kilobytes. The resulting image will always be about 16 megabytes larger, due to the overhead of the bootloader
- IMAGE_ROOTFS_SIZE = "450000"
Set the width and height of the display. Note you may need to make kernel patches in order to force it to PAL mode, or to add additional LCDs
- MACHINE_DISPLAY_WIDTH_PIXELS = "720"
- MACHINE_DISPLAY_HEIGHT_PIXELS = "480"

Start up a devshell
- bitbake virtual/kernel -c devshell &
Wait until the log says "task do_devshell: Started"
Enter the devshell
- screen -r
Add everything to git
- git init
- git add *
  - Git might throw an error saying "patches" won't be added, so remove that directory and try again (rm -rf patches; git add *)
- git commit -m "Commit"
Set up for building the kernel
- unset LDFLAGS
Make changes (for example):
- nano -w arch/arm/mach-stmp3xxx/lcd_lms350.c
- make
Test changes
- Copy arch/arm/boot/zImage to device
- Write kernel e.g. by running "config_util --cmd=putblock --dev=/dev/mmcblk0p1 --block=krnA < /media/usb/zImage"
Commit changes (for example):
- git add arch/arm/mach-stmp3xxx/lcd_lms350.c
- git commit -m "Changed timing on LCD"
Create a patch
- git format-patch HEAD~1
Copy the resulting .patch file to ~/chumby-oe/meta-chumby/recipes/linux/linux-falconwing/
- cp 0001-lcd-timings.patch ~/chumby-oe/meta-chumby-recipes/linux/linux-falconwing/
Exit the devshell
- exit
Edit the kernel recipe and add the new patch, adding the patch to the SRC_URI
- nano -w ~/chumby-oe/meta-chumby/recipes/linux/linux-falconwing_2.6.28.1.0.3454.bb
- file://0001-lcd-timings.patch \
Rebuild the kernel and bootloader
- bitbake virtual/kernel virtual/bootloader -c clean
- bitbake virtual/kernel
- bitbake virtual/bootloader

Copy meta-chumby/recipes/images/chumby-starter-image.bb to your own image file
- cp meta-chumby/recipes/images/chumby-starter-image.bb meta-chumby/recipes/images/my-local-image.bb
Edit the image and add any packages to DEPENDS and IMAGE_INSTALL
- nano -w meta-chumby/recipes/images/my-local-image.bb
Build the image
- bitbake my-local-image
Write the image out to disk
- sudo dd if=output-angstrom-.9/deploy/eglibc/images/chumby-falconwing/rom-chumby-falconwing-my-local-image.img of=/dev/sdb bs=8M # Write the resulting my-local-image to the SD card plugged into sdb