Simple Steps for the first boot

Choose a suitable directory for current work, say eworkdir under your home directory, we’ll refer ~/eworkdir as our workdir from now onwards

Prepare the pre built toolchain

Extract gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz in ~/eworkdir

tar -xvf gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz

You may rename to short convenient name

mv gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz gcc-linaro-4.9

Update PATH with new binaries in ~/eworkdir/gcc-linaro-4.9/bin as follows

export PATH=$HOME/eworkdir/gcc-linaro-4.9/bin:$PATH

The above setting is temporary and applicable to current shell only, add this to .bashrc or .bash_profile in your home directory to take this setting effective for every launch of new shell(.bashrc) or every login(.bash_profile) eg:-

vi ~/.bashrc #add above command at end of this file

You can verify the toolchain preparation as follows,preferbly launch a new terminal and test this to avoid any mistakes w.r.t PATH updations

arm-linux-gnueabihf-gcc -v should print suitable version, say 4.9.x

which arm-linux-gnueabihf-gcc if any error like command not found re-verify above steps

These steps are assuming that you are using 32 bit system for Host, follow expert steps for 64 bit Host machine and betetr location,other versions of the toolchain

Building the kernel

Extract the given tar ball with kernel source in workdir, i.e. ~/eworkdir, follow expert steps for the making story behind KERNEL source

tar -zxvf KERNEL.tar.gz -C ~/eworkdir

Let’s call the extracted kernel source, i.e. ~/eworkdir/KERNEL as KSRC from now onwards

Follow these steps for custom building of kernel source for the target

make ARCH=arm mrproper

#copy config-4.9.0-step1 as .config in KSRC follow expert steps for the making story behind config file

make ARCH=arm menuconfig #for further changes may skip initially

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs

Locate arch/arm/boot/zImage,arch/arm/boot/dts/am335x-boneblack.dtb w.r.t KSRC and copy them to a temporary directory say ~/eworkdir/deploy

Preparing rootfs

You may use myrootfs.img prepared based on yocto rootfs initially

follow expert for the making story behind myrootfs.img

Your First Boot

Install minicom on host computer, and configure it with device port of conencted TTL cable,typically /dev/ttyUSB0 and 1152008N1 configuration,here are some hints to configure minicom.

minicom -s

Serial port setup

hit A to change device file name, hit enter

hit E to change other baud rate settings using suitable key strokes, hit Enter

Save setup as dfl

and run minicom without -s option now (or) if minicom is already running use ctrl+a o to open the settings

You can use ctrl+a q to quit from minicom at any time.

Conenct TTL cable conenctors with debug port of target as mentioned in http://elinux.org/Beagleboard:BeagleBone_Black_Serial

Here is an example for Adafruit cables based on PL23xx chipset

Pin 1(GND) - Black(GND)

Pin 4(Rx) - Green(Tx)

Pin 5(Tx) - White(Rx)

Leave red conenctor open which is Vcc

Copy zImage, am335x-boneblack.dtb, bbrootfs.img or myrootfs.img to the 1st partition of SD card from ~/eworkdir/deploy

Now power on the board and stop the autoboot thru minicom by hitting any key within few seconds to enter u-boot console

mmcinfo To check the presence of SD card and basic information

mmc dev 0

fatls mmc 0:1 For listing of contents in first partition of SD card

fatload mmc 0:1 0x88080000 myrootfs.img note down the size of rootfs,33554432 for myrootfs.img,loading rootfs image as initrd

fatload mmc 0:1 0x82000000 zImage Loading kernel image from SD card to RAM

fatload mmc 0:1 0x88000000 am335x-boneblack.dtb Loading dtb file

setenv bootargs 'console=ttyO0,115200n8 root=/dev/ram0 rw initrd=0x88080000,33554432' replace size for other rootfs

bootz 0x82000000 - 0x88000000

Please follow some expert steps on choosing these addresses without collision.

Please follow booting methods for alternative methods on booting the board