dvsdk installing problem

I'm sorry. I am dealing with DM365EVM and DVSDK4.02 (I've never had to deal with the DM3730).
But I would suggest that you also use DVSDK 4.02.
In this case, I can say that the tftp configuration is done automatically by the script.
Script (setup.sh) itself automatically install an tftp-server on your host.
When the script runs, you will be asked some questions.
When you see the question...

Which directory do you want to be your tftp root directory?
Enter the path to the directory in which to store the boot files (uImage).
For example '/tftpboot'.
Script itself automatically put some files to this dir.
You will be asked about the IP-address. You must to confirm the proposed address (make sure it is correct).
Select Linux kernel location: 1: TFTP
Select root file system location: 1: NFS
When asked to specify a file name for the kernel Linux, I recommend that you specify a simple name such as 'uImage' (see below).
Then, the script will automatically prompt to place the U-Boot settings into your EVM.
Unfortunately, this procedure does not always work the first time. Need to practice. The main thing you will see options for the U-Boot, which will be printed on the terminal screen. Copy these settings (select them with the mouse and press Ctrl + Shift + C) and paste into a text editor like gedit (Ctrl + V).
If your board U-Boot already works fine, you can configure the settings manually (see below).

Please review the contents of '/tftpboot' directory on your host.
You can see some files. There should be a file named 'uImage' (or 'uImage-XXXX', where XXX - is something like "davinci", "evm" or so on).
It would be very useful to make a full access to the directory (so that you can do different operations on the files: rename, delete, or put new files).

$ sudo chown -R user /tftpboot

Instead, user, write your system(login) name.

You now have full access to this directory.

Copy right 'uImage-xxxxx' file as a file named simply 'uImage'.
When you compile the kernel Linux, then the compilation will create a file named 'uImage'.
That's why I recommend using this short name as the file for download via tftp.
Now you can easy manage these files.
If you have a few kernel files ('uImage-v1', 'uImage-last', etc), you can simply to copy right file as 'uImage'.
Alternatively, you can copy the current 'uImage' as 'uImage-last' and then use it in the future.

When U-Boot will boot, you need to press Enter. This will take you to the U-Boot command interface.
Look at the environment variables.

# printenv

Look at the variable 'bootfile'.
bootfile=uImage

Look at the variable 'serverip'.
serverip=host IP

The most important variable is 'bootargs'.

bootargs=console=ttyS0,115200n8(... etc... etc... etc...)

You can also copy this info to gedit: Ctrl+Shift+C(console) then Ctrl+V(gedit).

You need to insert some special instructions into 'bootargs' variable.

This variable should eventually look like this ...

bootargs=console=ttyS0,115200n8 (... etc... etc... etc...) root=/dev/nfs nfsroot=host IP:targetfs path ip=dhcp

Remember, we had backed up the arguments for the U-Boot when they were printed with the script (see above).
I recommend using the settings that are printed with script. There certainly has been a substrings: 'root=/dev/nfs', 'nfsroot=' etc.

When you print a list of variables with the command 'printenv', then the output is displayed as 'bootargs=console=ttyS0,115200n8 (... etc... etc... etc...)'.
Variable is set with the command 'setenv'.
In a text editor, simply add the 'setenv' to the begin of line and remove the sign '=' after the variable name.
Then you can copy a string with a command from a text editor (Ctrl+C) directly into the console (Ctrl+Shift+V)

In short.
You need to set:

# setenv serverip host IP

# setenv bootfile uImage

# setenv bootcmd 'dhcp;tftpboot;bootm'

# setenv bootargs console=ttyS0,115200n8 (... etc... etc... etc...) root=/dev/nfs nfsroot=host IP:targetfs path ip=dhcp

Check that the variables are set correctly.
# printenv

If all is well, write data into flash.

# saveenv

Reboot.

I hope you got it?

PS: I strongly recommend that you run minicom with the '-w' option.
Long lines will be wrapped to the new lines and you will not lose ends of the lines!
$ minicom -w