Hi, Thanks all for your replies. I managed to get ~25KB ticker/"nanoRTEMS" (with the remaining space left for the workspace), but that came with the requirement to delete printk and all output. I verified ticker runs till the end using GDB and some memory footprints.
Best, Hesham On Thu, Dec 18, 2014 at 6:40 PM, Marcos Díaz < marcos.d...@tallertechnologies.com> wrote: > > > > On Thu, Dec 18, 2014 at 6:34 AM, Hesham Moustafa <heshamelmat...@gmail.com > > wrote: >> >> Hi all, >> >> Thanks for all your helpful replies. I actually tried all the solution >> you mentioned: used printk, low-ticker (from example-v2), disabled >> newlib reentrancy (part of low-ticker configuration). I managed to get >> <32KB ticker with GCC optimization enabled (-Os), but I got some >> exceptions during initialization, however, the same code built without >> optimization (-O0) runs OK, but it's about 80KB. >> >> Marcos and Daniel, it's surprising that you got 9KB RTEMS, how did you >> do this (without the application optimizations and stacks) what APIs, >> managers, and CPUKIT code did you use, and what others did you give >> up? > > > My bad, since we were having problems with using RTEMS in an environment > with 32kb of RAM but with much more ROM, I though you had the same problem. > That size was of the used RAM (data, vector and bss sections) not of the > total used space. > Sorry about that. > >> > > >> Sebastian, the 32KB is for both code and data. Although there is 32MB >> external memory, it's very slow compared with local memories. The idea >> of getting rid of workspace appeals to me. Does this include >> discarding malloc, heap stuff? And how can this be done? >> >> Thanks, >> Hesham >> >> On Thu, Dec 18, 2014 at 7:58 AM, Sebastian Huber >> <sebastian.hu...@embedded-brains.de> wrote: >> > Hello, >> > >> > is this 32KiB for code and data? >> > >> > You should also disable the Newlib reentrancy: >> > >> > #define CONFIGURE_DISABLE_NEWLIB_REENTRANCY >> > >> > Try to add: >> > >> > CFLAGS_OPTIMIZE_V += -ffunction-sections -fdata-sections >> > >> > LDFLAGS = -Wl,--gc-sections >> > >> > to the *.cfg file of the BSP. You need a proper linker command file to >> use >> > these options. >> > >> > Avoid printf() and instead use printk() or no output. >> > >> > For a really small RTEMS we need the constructor based initialization. >> We >> > should probably also get rid of the workspace and use static >> initialization >> > only. >> > >> > >> > On 17/12/14 17:00, Hesham Moustafa wrote: >> >> >> >> Hi all, >> >> >> >> I am working on reducing RTEMS size to fit into <32KB as every Epiphay >> >> core has only 32KB of local memory. I was able to get hello and >> >> minimum samples with aggressive size reduction by manually removing >> >> un-needed code. Currently I only use libcsupport, sapi, score, rtems >> >> built for cpukit only, and for each, some source code files were >> >> removed. No IO, no FS, no barrier, event, managers are included. And I >> >> added -Os flag. However when building ticker, the .text area overflows >> >> the 32KB local memory by about 8KB. >> >> >> >> The question is, what are the very basic mandatory sources/libraries >> >> and/or managers that are enough to build ticker? >> >> >> >> Regards, >> >> Hesham >> >> _______________________________________________ >> >> devel mailing list >> >> devel@rtems.org >> >> http://lists.rtems.org/mailman/listinfo/devel >> > >> > >> > -- >> > Sebastian Huber, embedded brains GmbH >> > >> > Address : Dornierstr. 4, D-82178 Puchheim, Germany >> > Phone : +49 89 189 47 41-16 >> > Fax : +49 89 189 47 41-09 >> > E-Mail : sebastian.hu...@embedded-brains.de >> > PGP : Public key available on request. >> > >> > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. >> > >> _______________________________________________ >> devel mailing list >> devel@rtems.org >> http://lists.rtems.org/mailman/listinfo/devel >> > > > -- > > ______________________________ > > <http://www.tallertechnologies.com> > > > Marcos Díaz > > Software Engineer > > > San Lorenzo 47, 3rd Floor, Office 5 > > Córdoba, Argentina > > > Phone: +54 351 4217888 / +54 351 4218211/ +54 351 7617452 > > Skype: markdiaz22 > >
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