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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