[En-Nut-Discussion] Realy strange linker problem with NutOS 4.4.0 for Ethernut 3.0 (ARM)

[Harald Kipp]

Ole Reinhardt schrieb:
> Strange is, that all other funcions provided in nut/c/string/ are not
> linked either and seem to be provided by newlib. Using them does not
> trigger this problem.

nut/c/ provides all required function in case the toolchain comes 
without any runtime library. This had been the case in early times when 
Nut/OS was ported to the GameBoy Advance.

Today the ARM runtime library is provided by newlib and the AVR runtime 
by avrlibc. nut/c/ is not used in these cases.

Those runtime functions, which need special OS support, are located in 
nut/crt, like stdio functions as well as malloc() and friends. 
Unfortunately strdup() is not just a simple string function, but 
requires malloc(). However, libraries like newlib do not simply 
reference malloc() within strdup() but do more complex things, which in 
turn create additional system specific references like syscall().

Actually strdup() should be in nut/crt, although the header string.h 
refers to functions in nut/c/string. Actually the strdup() prototype 
should be in memory.h, but that would break well established standards.

Harald