Hi, I compiled and linked an application for ARM in thumbmode: -Werror -Wall -Wmissing-prototypes -fstrict-aliasing -Wall -mthumb -mthumb-interwork -mlittle-endian -msoft-float -pipe -mcpu=arm920t -fshort-enums -mstructure-size-boundary=8 -ggdb -nostdlib .... [many libs] lib_gcc_gnu/libgcc.a The application size increased, exeeded 4 MB (working) and finally around 4 MB and I ended up with the linker error "relocation truncated to fit: R_ARM_THM_PC22": relocation truncated to fit: R_ARM_THM_PC22 against symbol `_call_via_r4' defined in .text section in /tmp/x/lib_gcc_gnu/libgcc.a(_call_via_rX.o) ../../../../../myfile.c:238: relocation truncated to fit: R_ARM_THM_PC22 against symbol `_call_via_r3' defined in .text section in /tmp/x/lib_gcc_gnu/libgcc.a(_call_via_rX.o) [more similar errors, depending on my #defines/my code various symbols from various source files] I tried using the GCC option `-mlong-calls' but it did not help, I got similar errors (various `relocation truncated to fit'). It works when I compile in ARM instruction set mode (-marm): -Werror -Wall -Wmissing-prototypes -fstrict-aliasing -Wall -marm -mthumb-interwork -mlong-calls -mapcs -mlittle-endian -msoft-float -pipe -mcpu=arm920t -fshort-enums -mstructure-size-boundary=8 -ggdb but for the price of 20% more code (and people reported specific strange problems remote debugging with gdb if -marm was used). Someone told me that the maximum limit for code in ARM thumb mode is 4 MB and there would be nothing someone could do against (and thus, `-mlong-calls' cannot have any effect) and this would be an ARM architecture limitation. Is this correct? I searched the internet and read about `trampolines' and the general possibility to have small wrapper functions in ARM code able to execute very long calls (gigabyte range). Compilers/linkers could theoretically automatically use such "wrappers". This information is in contrast to the previous one. How is it correct? Where can I learn more? I have to state that I tried a very old gcc version (3.4.3) but since I was told that my problem would be a architectural systematic limitation of ARM thumb mode, I did not try a newer version. Any help appreciated! Best regards, Steffen
