[U-Boot-Users] FW: u-boot ppc440epx bootstrap configuration without eval board
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-----Original Message----- From: Stefan Roese [mailto:sr@denx.de] Sent: Wednesday, April 02, 2008 12:01 PM To: linuxppc-embedded@ozlabs.org Cc: Dave Cogley Subject: Re: u-boot ppc440epx bootstrap configuration without eval board
On Wednesday 02 April 2008, Dave Cogley wrote:
Disregard the boot strapping problem. It appears we are hardwired
strapped
to use option "C" however my CPU is not being recognized as a 667MHz. Which option should I be using for the 667MHz processor?
First, this is the wrong mailing list for this discussion. Please post to the U-Boot list instead.
But here some general comments:
The bootstrap controller has multiple configuration options. Some of them result in hardwired frequencies (CPU, PLB, OPB...), and some of them load the PLL setup from an I2C EEPROM. Using this bootstrap EEPROM is the most flexible solution. If you have only option "C", then you hardwired to 533MHz. There is no way to "detect" which frequency this CPU is labeled.
But it *is* possible to reconfigure the PLL from within U-Boot an reset the PPC to run with this different PLL setup. I just recently added some code the u-boot-ppc4xx custodian repository.
Let's continue this thread on the U-Boot list.
Best regards, Stefan
===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de =====================================================================
On Wednesday 02 April 2008, Dave Cogley wrote:
Disregard the boot strapping problem. It appears we are hardwired strapped to use option "C" however my CPU is not being recognized as a 667MHz. Which option should I be using for the 667MHz processor?
First, this is the wrong mailing list for this discussion. Please post to the U-Boot list instead.
But here some general comments:
The bootstrap controller has multiple configuration options. Some of them result in hardwired frequencies (CPU, PLB, OPB...), and some of them load the PLL setup from an I2C EEPROM. Using this bootstrap EEPROM is the most flexible solution. If you have only option "C", then you hardwired to 533MHz. There is no way to "detect" which frequency this CPU is labeled.
But it *is* possible to reconfigure the PLL from within U-Boot an reset the PPC to run with this different PLL setup. I just recently added some code the u-boot-ppc4xx custodian repository.
Do you really have no I2C bootstrap EEPROM? If not then take a look at cpu/ppc4xx/cpu_init.c and search for reconfigure_pll(). This should do the trick.
But again, you have no chance to detect which 440EPx version is running on your board. So if you have boards equipped with 533MHz and 677MHz, this U-Boot version will run on all boards with the same speed. If you need different settings you really need the bootstrap EEPROM and configure board dependant settings.
Best regards, Stefan
===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de =====================================================================
participants (2)
-
Dave Cogley -
Stefan Roese