RTEMS stack + TSIM-LEON2 weird behaviour

[Aitor Viana]

Actually it is not completely off-topic, I tell you why...

If I disassemble the executable and go to the hard_reset function:

40001000 <hard_reset>:
40001000:       03 10 00 00     sethi  %hi(0x40000000), %g1
40001004:       82 10 60 00     mov  %g1, %g1   ! 40000000 <RAM_START>
40001008:       81 98 40 00     mov  %g1, %tbr
4000100c:       83 48 00 00     rd  %psr, %g1
40001010:       84 00 60 01     add  %g1, 1, %g2
40001014:       84 08 a0 07     and  %g2, 7, %g2
40001018:       86 10 20 01     mov  1, %g3
4000101c:       87 28 c0 02     sll  %g3, %g2, %g3
40001020:       81 90 c0 00     mov  %g3, %wim
40001024:       82 10 60 20     or  %g1, 0x20, %g1
40001028:       81 88 40 00     mov  %g1, %psr
4000102c:       01 00 00 00     nop
40001030:       01 00 00 00     nop
40001034:       01 00 00 00     nop
40001038:       0d 10 00 01     sethi  %hi(0x40000400), %g6
4000103c:       8c 11 a3 c0     or  %g6, 0x3c0, %g6     ! 400007c0
<_ERC32_MEC_Timer_Control_Mirror>
*40001040:       dc 21 80 00     st  %sp, [ %g6 ]*
40001044:       23 10 00 4a     sethi  %hi(0x40012800), %l1
40001048:       a2 14 61 64     or  %l1, 0x164, %l1     ! 40012964
<Configuration>
4000104c:       e6 04 60 04     ld  [ %l1 + 4 ], %l3
*40001050:       9c 23 80 13     sub  %sp, %l3, %sp
40001054:       9c 2b a0 0f     andn  %sp, 0xf, %sp
40001058:       bc 10 00 0e     mov  %sp, %fp
*4000105c:       01 00 00 00     nop
40001060:       05 10 00 4a     sethi  %hi(0x40012800), %g2
40001064:       84 10 a0 a0     or  %g2, 0xa0, %g2      ! 400128a0
<_endtext>
40001068:       07 10 00 4a     sethi  %hi(0x40012800), %g3
4000106c:       86 10 e0 a0     or  %g3, 0xa0, %g3      ! 400128a0
<_endtext>
40001070:       09 10 00 4d     sethi  %hi(0x40013400), %g4
40001074:       88 11 22 70     or  %g4, 0x270, %g4     ! 40013670
<__bss_start>
40001078:       80 a0 80 03     cmp  %g2, %g3
4000107c:       02 80 00 09     be  400010a0 <copy_data+0x1c>
40001080:       01 00 00 00     nop


Find in bold where the %sp is modified. There is not single instruction to
set up the %sp register. The first one stores the VALUE of the %sp into the
address pointed by %g6, and the next operation over the %sp subtract fro
%sp, so the %sp value should be 0xFFFFXXXX ??? and this is RTEMS business.

Again the question is where the %sp is set, in RTEMS ?

the ./lib/libbsp/sparc/shared/start.S file matches with the disassemble
code...


On Tue, May 6, 2008 at 11:41 AM, Ralf Corsepius <ralf.corsepius at rtems.org>
wrote:

>
> On Tue, 2008-05-06 at 10:16 +0200, Aitor.Viana.Sanchez at esa.int wrote:
> >
> > Hi all,
> >
> > I've got some weird (for me) when executing the rtems-hello example in
> > the tsim-leon2 professional version.
>
> Off topic for this list - Ask Gaisler.
>
> Ralf
>
>
>
>
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