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Re: problem of using both libgloss and libc


Dai,

  For now, supply the definition of errno, either in your main program or add another stub
with:  int errno; in it.  I am going to add an errno stub to libnosys so that if not defined,
libnosys will supply a definition.

  The arm has all of the syscalls embedded together inside newlib so putting -lc can end up
dragging them all in at once.  In your case, you had already supplied a _write syscall via -lnosys
so you got the error.  It is my future goal to get the syscalls out of newlib and into libgloss.

-- Jeff J.

Dai Yuwen wrote:
Hi, Dear All

I want to use the libgloss version of _write to run applications on a bare ARM board. I find _write use libc:

c:/bar/bin/arm-elf-gcc -c -mlittle-endian -A 'endian(little)' -DMACHINE_TYPE
_ARM -w -O0 -g -gstabs main.c
c:/bar/bin/arm-elf-ld -Ttext 1008000 -Tdata 101A000 -Tbss 1030000 -n -N -nostart
upfiles -static -EL -e_start -L"E:/home/yuwen/tmp/newlib" -T"a1.ld" -o a1.elf s
tart_up.o main.o -lnosys c:/bar/lib/gcc-lib/arm-elf/3.2.3/libgcc.a
main.o: In function `__main':
main.c:16: warning: _write is not implemented and will always fail
/cygdrive/c/bar/arm-elf/lib/libnosys.a(write.o): In function `_write':
/cygdrive/c/build/newlib-1.11.0/libgloss/libnosys/write.c:21: undefined referenc
e to `errno'


Then I add -lc to the linker, but found libc also had a _write:
c:/bar/bin/arm-elf-gcc -c -mlittle-endian -A 'endian(little)' -DMACHINE_TYPE
_ARM -w -O0 -g -gstabs main.c
c:/bar/bin/arm-elf-ld -Ttext 1008000 -Tdata 101A000 -Tbss 1030000 -n -N -nostart
upfiles -static -EL -e_start -L"E:/home/yuwen/tmp/newlib" -T"a1.ld" -o a1.elf s
tart_up.o main.o -lnosys -lc c:/bar/lib/gcc-lib/arm-elf/3.2.3/libgcc.a
main.o: In function `__main':
main.c:16: warning: _write is not implemented and will always fail
/cygdrive/c/bar/arm-elf/lib/libc.a(syscalls.o): In function `_write':
/cygdrive/c/build/newlib-1.11.0/newlib/libc/sys/arm/syscalls.c:340: multiple def
inition of `_write'
/cygdrive/c/bar/arm-elf/lib/libnosys.a(write.o):/cygdrive/c/build/newlib-1.11.0/
libgloss/libnosys/write.c:19: first defined here
c:/bar/bin/arm-elf-ld: Warning: size of symbol `_write' changed from 24 to 120 i
n /cygdrive/c/bar/arm-elf/lib/libc.a(syscalls.o)
make: *** [a1.elf] Error 1


If I put -lc before -lnosys, the link was OK. But the libgloss version of _write was masked by libc's. How do sovle this problem? My intent is to use stdio functions on a ARM board without OS.

Best regards,
Dai Yuwen




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