[Gta04-owner] Find out if you have a 800 MHz or 1 GHz DM3730 in your GTA04

Dr. H. Nikolaus Schaller hns at goldelico.com
Mon Sep 10 15:29:00 CEST 2012

Am 10.09.2012 um 14:41 schrieb Denis 'GNUtoo' Carikli:

> On Mon, 10 Sep 2012 14:01:45 +0200
> "Dr. H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>> We had produced some GTA04 with a DM3730CBP100 chip variant (to find
>> out if the production problems could depend on different chip
>> suppliers) which is specified for 1 GHz clock (note that it is
>> possible to overclock all variants...).
>> To make it easier to find out which chip variant is built into a
>> given device, we have added a tiny patch to U-Boot that reads out the
>> config register and sets the "mpurate" kernel command line argument
>> to "800" or "1000".
>> The hw-tester script of the Debian/LXDE can then simply
>> parse /proc/cmdline to find out and report the max. official clock
>> rate.
> I guess it could also be done totally in userspace(as root):
> root at om-gta04:~# devmem2 0x4800244C w
> /dev/mem opened.
> Memory mapped at address 0xb6fa2000.
> Read at address  0x4800244C (0xb6fa244c): 0x00000C00
> root at om-gta04:~# python
> Python 2.7.3 (default, Aug  7 2012, 19:02:36) 
> [GCC 4.7.2 20120706 (prerelease)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> 0x00000C00 & (1<<9)
> 0
> Denis.

Yes, that should also work.

But there are kernels that want to see the "mpurate" bootarg being set properly.

E.g. http://processors.wiki.ti.com/index.php/OMAP35x_DVEVM_Bootargs_Options#Setting_the_MPU_Rate_from_bootargs

This is why I have added it to U-Boot for the default GTA04 installation.


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