Re: Problems during shifting syscalls from /sys to /libgloss

[Jeff Johnston <jjohnstn at redhat dot com>]

Bhushan Attarde wrote:
> Hi,
>  
>
> We are working on GNU based tool chain for infineon xc16x
> microcontroller.
> Currently the syscalls are in /newlib/libc/sys and we are trying to
> shift them to /libgloss.
>  
> So after some google search we found some way to do that.......
> And done some changes which are as follows:
>
>  
>  *  newlib-1.15.0/configure.in    : removed target-libgloss from
> noconfigdirs for xc16x-*-*
>  *  configure  : regenrate
>  *  newlib-1.15.0/newlib/configure.host: : set sys_dir to empty for
> xc16x-*-
> And set syscall_dir to xc16x
>
>  *  configure  : regenerate 
>  *  newlib/libc/sys/xc16x/ configure.in : removed
>  *  newlib/libc/sys/xc16x/ configure : removed
>
>  *  newlib/libc/sys/xc16x/ crt0.s : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ close.s : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ create.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ getchar1.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ isatty.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ lseek.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ mem-layout : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ misc.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ open.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ putchar.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ puts.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ read.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ sbrk.c: moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ syscalls.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ trap-handle.c : moved to libgloss/xc16x
>  *  newlib/libc/sys/xc16x/ write.c : moved to libgloss/xc16x
>
>  * newlib/libc/sys/xc16x : reomoved
>  
>  *  libgloss/xc16x/configure.in : new
>  *  libgloss/xc16x/configure : regenerate
>
>  
>
> With these changes I built the tool chain, it got built without any
> error.
>
> But when I tried to compile one of our sample program I got the
> following errors...............
>
>  
> /home/bhushana/XC16X/run/xc16x-elf/lib/gcc/xc16x-elf/4.2.0/../../../../x
> c16x-elf/lib/xc16xl/libg.a(lib_a-makebuf.o): In function `___smakebuf':
>
> makebuf.c:(.text+0x1fb): undefined reference to `_isatty'
>
> makebuf.c:(.text+0x1fc): undefined reference to `_isatty'
>
> /home/bhushana/XC16X/run/xc16x-elf/lib/gcc/xc16x-elf/4.2.0/../../../../x
> c16x-elf/lib/xc16xl/libg.a(lib_a-sbrkr.o): In function `__sbrk_r':
>
> sbrkr.c:(.text+0x1d): undefined reference to `__sbrk'
>
> sbrkr.c:(.text+0x1e): undefined reference to `__sbrk'
>
> /home/bhushana/XC16X/run/xc16x-elf/lib/gcc/xc16x-elf/4.2.0/../../../../x
> c16x-elf/lib/xc16xl/libg.a(lib_a-closer.o): In function `__close_r':
>
> closer.c:(.text+0x1b): undefined reference to `__close'
>
> closer.c:(.text+0x1c): undefined reference to `__close'
>
> /home/bhushana/XC16X/run/xc16x-elf/lib/gcc/xc16x-elf/4.2.0/../../../../x
> c16x-elf/lib/xc16xl/libg.a(lib_a-fstatr.o): In function `__fstat_r':
>
> fstatr.c:(.text+0x25): undefined reference to `__fstat'
>
> fstatr.c:(.text+0x26): undefined reference to `__fstat'
>
> /home/bhushana/XC16X/run/xc16x-elf/lib/gcc/xc16x-elf/4.2.0/../../../../x
> c16x-elf/lib/xc16xl/libg.a(lib_a-lseekr.o): In function `__lseek_r':
>
> lseekr.c:(.text+0x2d): undefined reference to `__lseek'
>
> lseekr.c:(.text+0x2e): undefined reference to `__lseek'
>
> collect2: ld returned 1 exit status
>
> make: *** [Mathtest.out] Error 1
>
>  
>
> what went wrong ? Or the changes are incomplete and needs to do more?
> What should I need to do?

Hi Bhushan,

  Don't forget that the compiler needs to be informed of your change as 
well when it adds library references when linking.  If you have 
introduced a new library, you will have to either refer to it manually 
on your compile/link command or you will need to modify the compiler so 
it adds it automatically.

  A common way of implementing libgloss is to use an ld script.  The ld 
script contains all the information needed to link so all that is needed 
is to add: -Txxxx.ld to the compile/link command.  This is useful in the 
case of multiple board configurations as you can have yyyy.ld and 
zzzz.ld, etc...  One could modify the compiler to add options to do this 
automatically on behalf of the end-user (e.g. -mxxxxx translates to 
-Txxxxx.ld when linking) or if there is only one choice to hardwire the 
needed reference.

  Check out libgloss/mn10300/sim.ld for an example of an ld script. 
Note the GROUP directive to repeatedly search the given libraries.

-- Jeff J.