problem of using both libgloss and libc

[J. Johnston]

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
>