arm-elf-gcc: how to get rid of crt0.o (or how to get it)?
Boris Dušek
I compiled gcc for target arm-elf. I can't use a standard C library
(and an OS as well), since the target machine is only a User-mode ARM
emulator.
I get trouble with arm-elf-gcc requiring crt0.o:
arm-elf-gcc -g0 -O1 -march=armv5 -mno-thumb -ffreestanding -o prec
prec.c
/usr/local/lib/gcc/arm-elf/4.2.2/../../../../arm-elf/bin/ld: crt0.o:
No such file: No such file or directory
collect2: ld returned 1 exit status
prec.c is a simple program not requiring any C library routine. It is
performing just computations, without doing explicit input/output (the
emulator passes arguments manually in registers and gets result from
registers as well), and without doing anything requiring standard C
library.
How to get rid of the "crt0.o" requirement? Or how to get the crt0.o
for an environment without a C library and OS? In other words, how to
compile prec.c successfully?
OS: Mac OS X 10.4
arm-elf-gcc: 4.2 SVN branch
arm-elf-binutils: 2.18
Thanks for any idea,
Boris Dušek
Paul Pluzhnikov
> How to get rid of the "crt0.o" requirement?
Use '-nostdlib'
> Or how to get the crt0.o for an environment without a C library and OS?
echo "static int unused;" | arm-elf-gcc -march=armv5 -mno-thumb -o crt0.o -xc -
Cheers,
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Boris Dušek
wrote:
> =?utf-8?B?Qm9yaXMgRHXFoWVr?= <boris.du...@gmail.com> writes:
> > How to get rid of the "crt0.o" requirement?
>
> Use '-nostdlib'
Thanks, this got me started, to make it really work I needed 2
additional steps:
1. link libgcc.a, since software division routines present there are
used, but libgcc.a is apparently excluded when "-nostdlib" is
specified
2. tell linker that the entry point is not "_start", but
"main" ("_start" is apparently in the crt0.o or similar stdlib object
file)
So the final command-line looked the following way:
arm-elf-gcc -march=armv5 -g0 -mno-thumb -O1 -ffreestanding -nostdlib -
o prec prec.c -Wl,--entry=main `arm-elf-gcc -print-libgcc-file-name`
Thanks once again,
Boris
42Bastian Schick
<boris...@gmail.com> wrote:
>Hi,
>
>I compiled gcc for target arm-elf. I can't use a standard C library
>(and an OS as well), since the target machine is only a User-mode ARM
>emulator.
>
>I get trouble with arm-elf-gcc requiring crt0.o:
Use -nostartfiles rather than -nostdlib.
Anyway you should write your own startup to clear BSS.
--
42Bastian
Do not email to bast...@yahoo.com, it's a spam-only account :-)
Use <same-name>@monlynx.de instead !
abhishek kole
I facing Below error .Please help me with it
d:/nxp/s32ds.3.4/s32ds/build_tools/gcc_v6.3/gcc-6.3-arm32-eabi/bin/../lib/gcc/arm-none-eabi/6.3.1/../../../../arm-none-eabi/bin/real-ld.exe: cannot find crt0.o: No such file or directory
what should I do?
.I am using S32K144 MCU .and I am using GNU compiler for it .