ambarella from S2 sdk4.0
we make the it and get the "out" directory after we patch to the SDK.
Complie Command:
$ cd s2_linux_sdk/ambarella 
$ source build/env/Linaro-multilib-gcc4.8.env
$ cd boards/s2ipcam
$ make sync_build_mkcfg
$ make s2_ipcam_8gb_s288_config
*****************************
make menuconfig                 —————amba
or
make defconfig_public_linux     —————firstly compile with the defconfig file.
or	      
make menuconfig_public_linux    ————— kernel
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$ make -j(n)                    ————— n : the number of the CPUs.