From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <38E3BB77.890DB46D@email.sps.mot.com> Date: Thu, 30 Mar 2000 14:39:19 -0600 From: "Richard Hendricks" MIME-Version: 1.0 CC: linuxppc-embedded@lists.linuxppc.org Subject: Re: Another try at the run-from-Flash issue for MPC8xx/MBX/custom References: <38E27471.83CCAC10@innocon.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Doug, Do you have the I-Cache enabled when decompressing? What about disabling serialization? (Set ICTRL to 0x7) Doug Rogers wrote: > > I, too, would like to run from Flash. The question for me isn't speed, > isn't cost, nor EMI effects. It is simply a matter of size. We have a > very small area in which to squeeze the parts, and the best we could do > is 32M RAM and 16M ROM. Our application code is in the 10M range (text > only, even after chopping over half of it out!), but it is expected to > grow. So for us it's not really a matter of cost or (running) speed, > since the Flash runs fast enough for our purposes. > > As another constraint, our card needs to be able to run very soon after > power-up. I've hacked the LynxOS startup monitor to detect either gzip'd > or bzip2'd KDI's. I've timed the decompression of our smaller test image > and it takes over 40 seconds on a 40MHz MBX860 board. That's too slow. > We could live with 20, perhaps, but not much more than that. For now I > boot my images over the network since our MBX board has only 4M Flash. > It's faster than decompressing! > > With LynxOS, we're able to keep in Flash both the text sections of the > kernel AND of all binaries on the filesystem. Wow! That allows us to put > only the RAM disk and vector/data/bss sections into RAM. Shweet! > > I was hoping that Linux was to that point, but apparently not. Just > having the kernel run from ROM would be helpful for now, so if anyone > out there has done so, I'd be very appreciative of any feedback. > > Thanks! > > Doug > > -- > --_._-__-____------_--_-_-_-___-___-____-_--_-___--____-___--_-__--___-_ > Doug Rogers, ICI | The strongest reason for the people to retain the > V:703.893.2007x220 | right to keep and bear arms is, as a last resort, > www.innocon.com | to protect themselves against tyranny in > ___________________| Government. [Thomas Jefferson] > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/