From mboxrd@z Thu Jan 1 00:00:00 1970 From: graeme.russ@gmail.com (Graeme Russ) Date: Fri, 20 Apr 2012 14:41:27 +1000 Subject: 32 bit kernel on 64 bit machine In-Reply-To: References: Message-ID: To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org Hi Krishna, On Fri, Apr 20, 2012 at 2:37 PM, er krishna wrote: > > On Apr 20, 2012 12:16 PM, "Graeme Russ" wrote: >> >> Hi Krishna, >> >> Please keep ML Cc'd > yep > >> >> On Fri, Apr 20, 2012 at 1:57 PM, er krishna wrote: >> > Graeme, >> > >> > Thanks for the reply. >> > >> > On Fri, Apr 20, 2012 at 11:49 AM, Graeme Russ >> > wrote: >> >> >> >> Hi Krishna, >> >> >> >> On Fri, Apr 20, 2012 at 1:45 PM, er krishna >> >> wrote: >> >> > Hi All, >> >> > >> >> > Is it possible to boot the 64 bit machine through 32 bit compiled >> >> > kernel >> >> > ? I >> >> >> >> Yes >> > >> > >> > How ? What are the exact steps ? I mean how I will compile the kernel >> > (flags >> > and all) that will boot on 64 bit processor ? My problem is I have 64 >> > bit >> > fc16 and Sandybridge 64 bit machine. I need to compile the kernel for 32 >> > bit >> > with these setup and boot it. >> >> The steps you performed I believe will have built a 32-bit kernel > yes but when booted it panic during initramfs stage. Is the initramfs the Fedora init ramfs? If so, maybe it has 64-bit user space >> >> > tried its compilation on fedora 16 64 bit and intel sandybridge 64 >> >> > bit >> >> > with >> >> > following option: >> >> > >> >> > >> >> > $ make ARCH=i386 menuconfig >> >> > >> >> > $ make ARCH=i386 ?j4 >> >> > >> >> > >> >> > but it failed to boot. Any suggestion if it can be done by any way. >> >> >> >> You cannot use a 32-bit kernel with 64-bit user-space >> >> >> > >> > Sorry, I didn't get you here. Do you mean to say that 64 bit application >> > won't work on 32 bit kernel. if its then its fine. >> >> Yes, that is what I mean't - If all you userspace (libraries, >> applications etc) are 64-bit then a 32-bit kernel cannot run them. You >> should have at least got a kernel panic that init could not be run >> > application will not run that i m agreed but the booting should be smooth. > Isnt it? > > I got panic during early stage of booting before calling of init. Can you post a log? You'll need to setup logging to serial or net console >> By 'fine' you mean that your setup is fine and you tried to run the > > No it was not intended to say like this.? But first of all booting didnt > happen. > So there is no point of trying any application. > > Can you pls tell that booting and 32 bit application should run smoothly? > >> 32-bit kernel using 32-bit userspace? If so, there is obviously >> another problem. > > Watt problem? I would say the initramfs contains 64-bit user-space Regards, Graeme