View source for IoTGateway/BSP/Linux/AM335x/Add a Driver to Kernel by menuconfig

{{DISPLAYTITLE:Add a Driver to Kernel by menuconfig}}
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= Add RTC Driver to Kernel by menuconfig =
You can add a driver to kernel by menuconfig. Here is an example to guide you
how to add a RTC driver (Seiko Instruments S-35390A) to Linux kernel. we still 
use the RSB-4220 as demo.  Please refer to the following steps:
* Open "Terminal" on Ubuntu host PC.
* $ sudo su (Change to “root” authority)
* Input user password.
* # cd $(BSP)/scripts/
* # source setenv.sh (To configure the developing environment automatically)
* # ./cfg_kernel.sh am335x_rsb4220_defconfig
* # ./cfg_kernel.sh menuconfig
Then you will see a GUI screen (Linux Kernel Configuration) as below:
[[Image: menuconfig.png]]<br>

* Select “Device Drivers”->”Real Time Clock”, you will see an option “Seiko Instruments S-35390A” on the list. Choose this option then exit and save your configuration.
[[Image: menu2.png]] <br>
* Change directory to “source/linux-3.2.0-psp04.06.00.11/arch/arm/mach-omap2”, edit the “board-rsb4220.h” and “board-advantech.c”. Please add below codes to source/linux-3.2.0-psp04.06.00.11/arch/arm/mach-omap2/board-rsb4220.h :
<pre>
/* I2C */
static struct i2c_board_info mxc_i2c0_board_info[] __initdata = {
{
I2C_BOARD_INFO("s35390a", 0x30),
},
}
</pre>
* Please add below codes to source/linux-3.2.0-psp04.06.00.11/arch/arm/mach-omap2/board-advantech.c:
<pre>
omap_register_i2c_bus(1, 100, am335x_i2c0_boardinfo,
ARRAY_SIZE(am335x_i2c0_boardinfo));
</pre>

* Please refer to [[IoTGateway/BSP/Linux/AM335x/AM335x_LBV6_User_Guide#BSP_Building_Guide|BSP Building Guide]] to rebuild the kernel with RTC driver (Seiko Instruments S-35390A) after completing above steps.