From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from web32211.mail.mud.yahoo.com (web32211.mail.mud.yahoo.com [68.142.207.142]) by ozlabs.org (Postfix) with SMTP id A088067B17 for ; Wed, 27 Apr 2005 14:44:32 +1000 (EST) Message-ID: <20050427043750.93023.qmail@web32211.mail.mud.yahoo.com> Date: Tue, 26 Apr 2005 21:37:50 -0700 (PDT) From: Frank To: Stuart Yoder , 'Wolfgang Denk' MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: 'linuxppc-dev list' Subject: RE: PowerPC + SMP List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --- Stuart YoYoderststuartoyoderoconformativeom> wrote: > > We've run into a few issues with U-boot, but they are not > ununsolveable > > -it doesn't provide an alternate execution path for the 2nd > CPU when it > is started by the kernel You have to set a flag or something to sync. the booting process of the other cpu's > -U-boot needs to detect which CPU is executing > -U-boot on the 2nd CPU should not execute any platform/board > specific We did this by having the cpcpuead a register that is updated as each cpcpuomes up. > setup code-- this is stuff you only want to do once > -U-boot on the 2nd CPU cannot relocate itself to SDSDRAMecause > Linux is > already running there and assumes it owns all of memory You have to carve the memory up by dividing the total memory by the number of cpus. This can be done at complie time with a #define. I did this in board_init_f I believe. We had a quad 7450 board with each one booting in sequence and orchestrated by the master CPU (cpu 0). The master held each one in reset until the previous cpu reported in. Unfortunately, I don't work for the company anymore and don't have access to the source. BTW, it was done right because it worked.:-) > -it needs some way of getting to the Linux kernel entry point > for > secondary CPUs > -it also appears that it should set up HID1 (other stuff??) > for SMSMP> systems > > Stuart > > > -----Original Message----- > > From: Wolfgang DeDenkmamailtodwdedenxede > > Sent: Tuesday, April 26, 2005 12:35 PM > > To: Stuart YoYoder> > Cc: 'lilinuxppcedevist' > > Subject: Re: PoPowerPC SMSMP > > > > > > In message <054301c54a6f$d1cf82b0$2f010a0a@foundation.com> > you wrote: > > > > > > I am using U-boot on my SMSMPystem and U-boot is not SMSMP> aware. Do > > > you > > > > Strictly speaking this statement is wrong. > > > > So far I am not aware of a port of U-Boot to a SMSMPystem. > > If there was such a port, and if it was properly done, > > then U-Boot probably _were_ SMSMPware. > > > > Best regards, > > > > Wolfgang DeDenk> > > > -- > > Software Engineering: Embedded and ReRealtimeystems, > Embedded Linux > > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: > > wdwdedenxedevery program has at least one bug and can be > > shortened by at least one instruction -- from which, > > by induction, one can deduce that every program can be > > reduced to one instruction which doesn't work. > > > > > > > > > _______________________________________________ > LiLinuxppcedevailing list > LiLinuxppcedevzozlabsrorg> hthttps/ozozlabsrorgailman/lilistinfoilinuxppcedev> __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com