From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from AM1EHSOBE003.bigfish.com (am1ehsobe003.messaging.microsoft.com [213.199.154.206]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Cybertrust SureServer Standard Validation CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 7FDF1B6F67 for ; Thu, 26 May 2011 04:52:34 +1000 (EST) From: McClintock Matthew-B29882 To: "Gabbasov, Andrew" Subject: Re: Booting p4080ds on non-0 cpu Date: Wed, 25 May 2011 18:52:23 +0000 Message-ID: References: In-Reply-To: Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Cc: "linuxppc-dev@lists.ozlabs.org" , "Blanchard, Hollis" Reply-To: McClintock Matthew-B29882 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, May 25, 2011 at 7:16 AM, Gabbasov, Andrew wrote: > Hello Matthew, > > You have made a patch > "powerpc/fsl_booke:=A0Add=A0support=A0to=A0boot=A0from=A0core=A0other=A0t= han=A00" some time > ago, so you probably worked with booting the kernel on a cpu subset, > particularly on the core other than 0. > > Could you please describe any details how you ran the kernel from u-boot = on > a non-0 cpu? I did this via kexec not via u-boot. In this method I would reboot on any one of the cores and it would bring up the other cores. > I have a problem trying to boot linux on p4080ds platform on any non-0 cp= u > (as a first step to running AMP or mixed AMP/SMP configuration). I'm tryi= ng > to run 2.6.34.6 kernel with some Freescale patches in SMP configuration w= ith > full original device tree and device tree with some cpu nodes removed. I'= m > using the u-boot script, shown at the bottom of this message. > > If I run "bootm go" after the script commands (thus running the kernel on > cpu 0), the kernel runs fine. > > When I'm trying to run the SMP kernel with full device tree on cpu 1 usin= g > the following commands after the script: > =A0 fdt boot 1 > =A0 cpu 1 release 0 1 c00000 - > the kernel begins to run, but soon crashes. Possible reasons > are:=A0"Unrecoverable FP Unavailable Exception", at nearly random > place;=A0memory allocation errors somewhere in DPAA=A0code and then segme= ntation > fault (sig 11); unknown exception (sig 4).=A0Sometimes it doesn't even sh= ow > anything on the console (too early exception?), but sometimes it boots > successfully up to the shell prompt. Is the single core boot stable at this point? > When I'm trying to run the SMP kernel with the device tree with cpu 0 > stripped out (commented out the whole cpu0 node and all properties referr= ing > to it with &cpu0), using the following commands after the script: > =A0 fdt boot 1 > =A0 cpu 1 release 0 0 c00000 - > =A0 [Note the difference in the parameter to 'cpu 1 release' command, > =A0=A0=A0 it should be a logical cpu number, which is different] > the result is almost the same, the kernel crashes too. The reasons are > similar to the above, with more often "Unrecoverable FP Unavailable > Exception". Can you send me the kernel boot logs and kernel defconfig? (off list perhap= s) > > Can you give any advise why can this happen, and what I could be doing > wrong? Did you build your kernel relocatable? Did you use the -b option when compiling your device tree? We do have a hypervisor for this part which might be a more suitable and tested solution depending on what you are trying to accomplish. I'm not sure that anyone has explicitly tested AMP on a p4080. -M=