Re:Re: gcc Cortex M4 bug ?

[matti h <matti at henttunen dot se>]

Not sure what you think looks insane?
the instructions or the code I use ?
Anyway's Ive tried to compile the same code on linux-eabi aswell 
with the same incorrect results.


/Matias

13.6.2013 12:25, matti h kirjoitti:
Hi,
Im trying to implement a dynamic linker for M4 mcu's.
But the generated code from gcc seems incorrect to me: im compiling using
arm-none-eabi-gcc: -mcpu=cortex-m4 -mthumb -O2 -ggdb  -Wstrict-prototypes
-Wunused-parameter -lmylib main.c -o test

For me this all looks insane :(

I would expect the 'arm-eabi' target being purely static and not knowing anything about shared libraries and dynamic linking, something equivalent to the 'arm-elf' target but with somehow different object format. Meanwhile targets like 'arm-linux*', 'arm-*bsd' etc. will
support dynamic linking. If we look at the Wikipedia page :

http://en.wikipedia.org/wiki/Application_binary_interface

there is told :

"The main differences of an EABI with respect to an ABI for general purpose operating systems are that privileged instructions are allowed in application code, dynamic linking is not required (sometimes it is completely disallowed), and a more compact stack frame
organization is used to save memory."

So if you change your target choice for instance to 'arm-linux-gnueabi' then you of course can produce shared libraries (.so files) etc. for some "equivalent" own operating system
which uses the same object format...