to generate an installable OpenWrt firmware image file with a size of e.g. 8MB:
Install OpenWrt Buildroot and its prerequisites on your OS.
ca. 3-4 GB of available hard disk space
SED should not be set. If it is, rununset SEDbefore compiling. (See Ticket 10612.)
GREP_OPTIONS should not have –initial-tab or other options affecting its output
Add/staging_dir/host/bin and/staging_dir/toolchain---/bin in front of your PATH variable in ~/.bashrc. The staging directory is created shortly after starting the build and the toolchain directory is created when the toolchain build begins. The build spawns multiple shells, some of which expect the toolchain binaries to be present in the PATH.
Update OpenWrt sources.
Update and install package feeds.
Configure the firmware image you want to obtain.
Start the build. This will automatically compile toolchain,cross-compile sources, package packages, and finally generate an image ready to be flashed.
Proceed to Installing OpenWrt
Updating Sources with Git
./scripts/feeds update -a
Make downloaded package/packages available in make menuconfig:
./scripts/feeds install -a
run make menuconfig and set target;
run make defconfig;
run make menuconfig and modify set of package;
run scripts/diffconfig.sh >mydiffconfig (save your changes in the
text file mydiffconfig);
run make V=s (build OpenWRT with console logging, you will look
where build failed.).