SolidRun's TI AM64x based build scripts

Introduction

Main intention of this repository is to build a buildroot based build environment for TI AM64x based product evaluation.

The build script provides ready to use images that can be deployed on a micro SD card.

Building Image

The build script will check for required tools, clone and build images and place results in output/ directory.

Docker build (recommended)

• Build the Docker image (Just once):

docker build --build-arg user=$(whoami) --build-arg userid=$(id -u) -t ti_am64x docker/

To check if the image exists in you machine, you can use the following command:

docker images | grep ti_am64x

• Run the build script:

docker run -i -t -v "$PWD":/ti_build -v /etc/gitconfig:/etc/gitconfig ti_am64x ./runme.sh

Native Build

Simply:

./runme.sh

Deploying

In order to create a bootable SD card, plug in a micro SD into your machine and run the following, where sdX is the location of the SD card got probed into your machine -

umount /media/<relevant directory>
sudo dd if=output/microsd-<hash>.img of=/dev/sdX

Booting Linux and Rootfs

SD card

By default, Linux will read rootfs from SD card, partition 2.
In order to load rootfs into RAM, please run the following command in U-boot:

Hit any key to stop autoboot:  0
=> run load_rootfs; boot

In this case, Linux won't load the rootfs from SD card.
Please note that all changes to the file system (creating/deleting files/directories) will be discarded every reboot.

Ethernet

In order to boot Linux kernel and rootfs over ethernet, you'll need a TFTP server to serve the required files.

Setting a TFTP server (From a different Linux machine in the same network)

• Install tftpd, xinetd and tftp.

apt-get install tftpd xinetd tftp

• Create the directory you'll use to store the booting files.

mkdir /path/to/boot/dir
chmod -R 777 /path/to/boot/dir
chown -R nobody /path/to/boot/dir

• Create /etc/xinetd.d/tftp, and write in the file:

service tftp
{
protocol        = udp
port            = 69
socket_type     = dgram
wait            = yes
user            = nobody
server          = /usr/sbin/in.tftpd
server_args     = /path/to/boot/dir
disable         = no
}

Edit /path/to/boot/dir according to your directory

• Restart service

service xinetd restart

• Copy booting files (which are in ti_am64x_build/tmp directory)into tftp directory

# Copy device tree
cp some_location/ti_am64x_build/tmp/am642-solidrun.dtb /path/to/boot/dir/

# Copy Kernel
cp some_location/ti_am64x_build/tmp/Image /path/to/boot/dir/

# Copy rootfs
cp some_location/ti_am64x_build/tmp/rootfs.cpio /path/to/boot/dir/

Retrieving booting files over ethetnet.

This part assumes that you have a tftp server in the same network, and that your board is in U-boot.

• Get IP address using dhcp command (ignore the error, we are using this command to get an IP address for a DHCP server)

=> dhcp
link up on port 1, speed 1000, full duplex
BOOTP broadcast 1
BOOTP broadcast 2
BOOTP broadcast 3
DHCP client bound to address 192.168.15.119 (2756 ms)
*** ERROR: `serverip' not set
Cannot autoload with TFTPGET

• Set the tftp server IP address.

setenv serverip <the.server.ip.addr>

• Load Kernel into RAM

setenv loadaddr ${kernel_addr_r}
tftpboot Image

• Load Device Tree into RAM.

setenv loadaddr ${fdt_addr_r}
tftpboot am642-solidrun.dtb

• Load rootfs into RAM.

setenv loadaddr ${ramdisk_addr_r}
tftpboot rootfs.cpio

• boot

booti ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}

Since rootfs is loaded into RAM, all changes to the file system (creating/deleting files/directories) will be discarded every reboot.

Features

MAC Addresses:

This SOM has 3 Ethernet interfaces, CPSW and 2 ICSSGs, hence, needs 3 MAC addresses.
U-boot will try to read these MAC addresses from an EEPROM in I2C bus 0, address 0x50.

• CPSW's MAC address will be read from offsets 0x00->0x05.
• First ICSSG's MAC address will be read from offsets 0x06->0x0b.
• Second ICSSG's MAC address will be read from offsets 0x0c->0x11.

If no valid MAC addresses are found, random MAC addresses will be used.
Here is an example on how to write your own MAC address from Linux:

# Write aa:bb:cc:dd:ee:ff as CPSW's MAC address:

i2cset -y 0 0x50 0 0xaa 0xbb 0xcc 0xdd 0xee 0xff i

# Verify by dumping the EEPROM content:

i2cdump -y 0 0x50