DHylands SGS2 Console

Using a serial adapter, connect the serial adapter to your PC using the micro USB cable. Run a terminal emulator on the PC, and set it to 115200 baud, n81, no HW or SW flow control.

In order to make /dev/ttyUSB0 have world readable permissions (so anybody can use the serial port), I created a file called ftdi.rules with the following content (for Ubuntu 12.04):

SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", MODE="0666"

You should copy the ftdi.rules file into /etc/udev/rules.d and then execute:

sudo service udev restart

And unplug and replug the FTDI USB adapter in

Power off the phone. Press and hold the HOME button and then plug in the serial adapter. The phone should automatically turn on and you should start to see bootloader messages coming out over the serial port. You can release the HOME button as soon as you start to see messages.

In the terminal emulator press and hold the RETURN key. You should drop into a prompt which looks like:

SBL>

You are now in the Samsung Primitive Bootloader. You can use the help command to see available commands. You should probably use the printenv command and record your environment settings. Now enter the following commands:

setenv BOOT_DELAY 3
setenv SWITCH_SEL 6543
setenv CMDLINE loglevel=7 console=ttySAC2,115200
saveenv
boot

and you should now be seeing kernel boot messages flowing by. Once the kernel has booted you should also be able to press RETURN and get to a console, although it will be interrupted by the messages flowing by.

The BOOT_DELAY being set to 3, makes it easier to drop into the boot loader later on.

To return the bootloader to the original settings, drop into the SBL> prompt as described above, and enter:

setenv BOOT_DELAY 0
setenv SWITCH_SEL 1
setenv CMDLINE loglevel=4 console=ram
saveenv
boot