DDR Clock Adjustment

• Brief DDR spec. of ODROID-C2 and available DDR clock sets
• Update Guide (1) for Ubuntu
• How to confirm if bl1 boot with the new DDR clock has been updated well

• The DDR parts of C2 support max DDR3-1866 (CL - tRCD - tRP : 13-13-13) and the limit of max DDR clock is 933MHz based on DDR part spec.
• Existing DDR clock and timing : 912MHz (912×2=1824) / 13-13-13

Here is the available DDR clock sets you can test.

This section is for Ubuntu. First, download c2_update_ddrclk.sh to your root filesystem.

$ wget http://dn.odroid.com/S905/BootLoader/ODROID-C2/c2_update_ddrclk.sh
$ chmod +x ./c2_update_ddrclk.sh

The usage of c2_update_ddrclk.sh is as following.

Usage : ./c2_update_ddrclk.sh  < DDR_CLK (1104 | 912 | 792 | 408) >

After updating, you must run reboot the system.

$ ./c2_update_ddrclk.sh 1104
$ reboot

Wht the output message while updating with c2_update_ddrclk.sh, you can confirm if update is done with the new DDR clock you choose as following.

$ ./c2_update_ddrclk.sh  1104

existing DDR clk is 912   <<<------
.....
.....
Update done!
Now let's check if update has been completed...
updated DDR clk is 1104 <<<------
updating DDR clock has been completed!!!

After reboot, you can check the DDR configuration using the following logs of boot loader if you have a usb-uart module kit.

BL2 Built : 11:44:26, Nov 25 2015. 
Board ID = 8
set vcck to 1100 mv
set vddee to 1070 mv
CPU clk: 1536MHz
DDR channel setting: DDR0 Rank0+1 same
DDR0: 2048MB(auto) @ 912MHz(2T)-13

Here is the script, c2_update_ddrclk.sh.

c2_update_ddrclk.sh

#!/bin/sh
#
# Copyright (C) 2016 Hardkernel Co,. Ltd
# Joy Cho <joy.cho@hardkernel.com>
#
# SPDX-License-Identifier:      GPL-2.0+
#
 
if [ -z $1 ]; then
        echo "Usage ./c2_update_ddrclk.sh <DDR_CLK (1104 | 912 | 792 | 408)>"
        exit 1
fi
 
if [ $1 != 1104 -a $1 != 912 -a $1 != 792 -a $1 != 408 ]; then
        echo "Wrong DDRCLK! Usage ./c1_update_ddrclk.sh <DDR_CLK (1104 | 912 | 792 | 408)>"
        exit 1
fi
 
DDRCLK=$1
 
bl1=/tmp/bl1.bin.hardkernel.$DDRCLK
tmp=/tmp/temp.bin
 
##### 1. check the current DDR clock ####
dd if=/dev/mmcblk0 of=$tmp bs=1 count=2 skip=43530 status=none
CUR_DDRCLK=$(hexdump -e '"%d"' $tmp)
 
if [ $DDRCLK -eq $CUR_DDRCLK ]; then
        echo "current ddr clk is already set as $DDRCLK MHz"
        exit 1
fi
 
echo "existing DDR clk is $CUR_DDRCLK"
 
##### 2. download bl1 binary from dn server ####
wget -P /tmp/ http://dn.odroid.com/S905/BootLoader/ODROID-C2/bl1.bin.hardkernel.$DDRCLK
if [ ! -f $bl1 ];then
        echo "error: bl1 binary doesn't exist"
        exit 1
fi
 
dd if=$bl1 of=/dev/mmcblk0 bs=1 count=442 status=none
dd if=$bl1 of=/dev/mmcblk0 bs=512 skip=1 seek=1 status=none
 
echo "Update done!"
 
##### 3. check the updated DDR clock ####
echo "Now let's check if update has been completed..."
 
dd if=/dev/mmcblk0 of=$tmp bs=1 count=2 skip=43530 status=none
 
CUR_DDRCLK=$(hexdump -e '"%d"' $tmp)
echo "updated DDR clk is $CUR_DDRCLK"
 
rm $bl1
rm $tmp
 
echo "updating DDR clock has been completed!!!"