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RE: Problems during shifting syscalls from /sys to /libgloss
- From: "Bhushan Attarde" <Bhushan dot Attarde at kpitcummins dot com>
- To: "Jeff Johnston" <jjohnstn at redhat dot com>
- Cc: <newlib at sources dot redhat dot com>, <crossgcc at sources dot redhat dot com>
- Date: Fri, 22 Jun 2007 18:54:50 +0530
- Subject: RE: Problems during shifting syscalls from /sys to /libgloss
Hi Jeff,
First of all thanks for your reply.
I followed your suggestion and the problem of undefined references got
solved and the applications are getting compiled successfully.
But now I got stuck into another problem........
We have our own defined syscall functions(_read, _write) for serial port
read/write operations. These functions are implemented in syscalls.c as
a source file.
But during application compilation libgloss syscalls functions are not
getting replaced by our own defined sycalls. This was not a problem when
syscalls were in libc/sys/.
This can be seen from disassembly listing (lss) files.
When sycalls were in libc/sys :
...................
.................
00c008d6 <__read>:
int _read (int file, char *ptr, int len)
{
c008d6: 88 10 mov [-r0],r1
c008d8: f0 10 mov r1,r0
c008da: 26 f0 08 00 sub r0,#0x8
c008de: ec f2 push r2
c008e0: ec f3 push r3
c008e2: c4 81 fe ff mov [r1+#0xfffe],r8
c008e6: c4 a1 fc ff mov [r1+#0xfffc],r10
c008ea: c4 91 fa ff mov [r1+#0xfffa],r9
c008ee: c4 b1 f8 ff mov [r1+#0xfff8],r11
*ptr=getkey();
c008f2: da c0 28 08 calls #seg:0xc0,#sof:0x828
c008f6: d4 31 fc ff mov r3,[r1+#0xfffc]
c008fa: d4 21 fa ff mov r2,[r1+#0xfffa]
c008fe: dc 43 extp r3,#0x1
c00900: b9 82 movb [r2],rl4
return (1);
c00902: e0 12 mov r2,#0x1
}
c00904: f0 42 mov r4,r2
c00906: fc f3 pop r3
c00908: fc f2 pop r2
c0090a: 06 f0 08 00 add r0,#0x8
c0090e: 98 10 mov r1,[r0+]
c00910: db 00 rets
..........................
When sycalls are now in /libgloss :
..........................
..........................
00c0e780 <__read>:
c0e780: 88 10 mov [-r0],r1
c0e782: f0 10 mov r1,r0
c0e784: e0 1b mov r11,#0x1
c0e786: f0 99 mov r9,r9
c0e788: f0 aa mov r10,r10
c0e78a: da c0 ac e7 calls #seg:0xc0,#sof:0xe7ac
c0e78e: 98 10 mov r1,[r0+]
c0e790: db 00 rets
.....................
So what is the problem ?
Did we miss something like macros etc.?
What should I need to do?
Thanks in advance
--Bhushan
-----Original Message-----
From: Jeff Johnston [mailto:jjohnstn@redhat.com]
Sent: Friday, June 15, 2007 9:46 PM
To: Bhushan Attarde
Cc: newlib@sources.redhat.com; crossgcc@sources.redhat.com
Subject: Re: Problems during shifting syscalls from /sys to /libgloss
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.