On Feb 7, 2008 12:04 AM, Tom Rhodes <<a href="mailto:trhodes@freebsd.org">trhodes@freebsd.org</a>> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">On Wed, 6 Feb 2008 23:36:19 -0500<br>"Mackenzie Morgan" <<a href="mailto:macoafi@gmail.com">macoafi@gmail.com</a>> wrote:<br><br>> You're running a 32bit kernel, then? You could theoretically address all<br>
> 4GB (and not a bit more) on 32bits, except that'd assume you had no drivers<br>> or firmware or anything. It varies by hardware just how much you'll see on<br>> a 32bit OS. Install 64bit, and you'll be good because that can<br>
> address....umm....Wikipedia says 16 exbibytes (1 exbibyte = 1024 pebibytes,<br>> 1 pebibyte = 1024 tebibytes, 1 tebibyte = 1024 gibibytes).<br><br></div>Yea, it's 32-bit. From what I can tell, PAE (physical address<br>
extentions) exist in the kernel file (perhaps I could rebuild and<br>try) and should, theoretically, give me access to the larger<br>amount of RAM. I was also thinking that the OS needs upgraded<br>to the 64-bit version; however, I need to double check and make<br>
sure that the CPU will actually run it. I doubt a 64-bit<br>version will run on a 32-bit CPU, but I've been told (may not<br>be correct) that a 64-bit CPU will run either or. On that,<br>as I've not tested either, I reserve the right to be wrong.<br>
<br>Maybe it's likely that even though PAE seems enabled in the<br>source (seen with make menuconfig), it's not enabled in the<br>default kernel - a rebuild, as noted above, may just fix this<br>entire issue.<br></blockquote>
</div><br>Ah, some hardware doesn't support PAE. That's down to your CPU, I think. I got a kernel panic on boot when I installed Ubuntu 7.10 Server on a laptop because the kernel is built for PAE. It said "CPU too old for this kernel." If your hardware doesn't support PAE, nothing can be done about that, AFAIK.<br>
<br>No, a 64bit OS will not run on 32bit hardware. It is true that 64bit hardware can do either, though. That's just a matter of using only half the registers. You can't magically double the number of available registers though.<br clear="all">
<br>-- <br>Mackenzie Morgan<br>Linux User #432169<br>ACM Member #3445683<br><a href="http://ubuntulinuxtipstricks.blogspot.com">http://ubuntulinuxtipstricks.blogspot.com</a> <-my blog of Ubuntu stuff<br>apt-get moo