> Subject: Re: [uClinux-dev] ucLinux and XIP memory savings > > Hi, > > it is quite some time ago since I tried XIP on uClinux/Coldfire, but > could not get it to run. I do not recall which exact problem I had, > because I was fine without it in the end. > > What is it you want to achieve? Is XIP the only possible option? > > In my case, I was hoping to reduce startup and boot time in general, > and I ended up with a different compression scheme for the kernel and > rootfs (U-Boot images), because load time from flash and decompression > were what really made my system slow. And, even more, flash access time > becomes an even more critical factor when using XIP. > > On the other hand, my system was quite specialized with only one > application running being started on boot and only terminated in case > of power failure or watchdog reset. ;-) However, this might be a common > scenario for many embedded applications. > > Just asking, because memory is not a cost factor any more in most > cases, so maybe focusing on XIP is not the way to go, especially > considering flash access being slower than DRAM in most cases anyways. >
I'm considering XIP, because it could potentially allow me to run a small microcontroller with just internal SRAM (which is very little) instead of adding external SDRAM. I'm hoping that XIP could help me save RAM here, because I don't need to load any program code into RAM. I'm talking about a small microcontroller system here, so any saving on RAM are very beneficial. In my case the access time to flash would be OK compared to external RAM. Especially when using a parallel NOR flash. There are D/I-caches on the chip as well and a tightly-coupled memory (TCM) module where critical code can be placed for low-latency access. So really, for now I just care about saving RAM as much as possible. XIP seems to help, but I'm looking for some numbers to help quantify the benefit. Thanks, Anna _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
