Quoth Anna Fischer: > I was wondering if anyone had any experiences they can share about using > XIP on ucLinux? As far as I can see it is supported for the bootloader, > the kernel and also for applications, if the toolchain supports this. My > question though is if anyone has done any studies on how much memory is > really saved doing XIP. Instead of copying executables to RAM, just > .data and .bss sections of programs are copied to RAM. Also, boot time > is usually reduced when using XIP. However, I'm quite keen to hear about > some practical examples on this and some real numbers on what is exactly > saved. Can anyone provide more information on this? I could not find any > resources online.
Many years ago, I had a look at XIP (but couldn't actually use it in practice because the bootloader I was using required the romfs to be compressed). During my investigation, I concluded that its primary benefit would be for running multiple copies of busybox (which happens quite often when running shell scripts etc) and in minimising memory fragmentation when running lots of little programs. One downside is that flash is typically slower than RAM, so actual execution would be slowed down a bit. (As a sidenote, another [even more tiny and barebones] device I've used intentionally copies and runs from RAM even though XIP is available because the flash is too slow for the firmware's requirements.) At the end of the day though my particular usage case didn't require lots of little programs, and it was easy to add more RAM, so I didn't worry about XIP too much. But YMMV. _______________________________________________ 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
