source: trunk/libs/newlib/src/libgloss/rx/crt0.S @ 444

/* Copyright (c) 2008, 2009, 2011 Red Hat Incorporated.
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met: 

     Redistributions of source code must retain the above copyright 
     notice, this list of conditions and the following disclaimer.

     Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.

     The name of Red Hat Incorporated may not be used to endorse 
     or promote products derived from this software without specific 
     prior written permission.

   This software is provided by the copyright holders and contributors
   "AS IS" and any express or implied warranties, including, but not
   limited to, the implied warranties of merchantability and fitness for
   a particular purpose are disclaimed.  In no event shall Red Hat
   incorporated be liable for any direct, indirect, incidental, special,
   exemplary, or consequential damages (including, but not limited to,
   procurement of substitute goods or services; loss of use, data, or
   profits; or business interruption) however caused and on any theory of
   liability, whether in contract, strict liability, or tort (including
   negligence or otherwise) arising in any way out of the use of this
   software, even if advised of the possibility of such damage.  */

        .text

        .global _start
_start:
.LFB2:
        mvtc    #0, psw
        /* Enable the DN bit - this should have been done for us by
           the CPU reset, but it is best to make sure for ourselves.  */        
        mvtc    #0x100, fpsw
        mov     #__stack, r0
        mvtc    #__vectors, intb

        /* Copy the .data section from ROM into RAM.  */
        mov     #__datastart, r1
        mov     #__romdatastart, r2
        mov     #__romdatacopysize, r3
#ifdef __RX_DISALLOW_STRING_INSNS__
        cmp     #0, r3
        beq     2f

1:      mov.b   [r2+], r5
        mov.b   r5, [r1+]
        sub     #1, r3
        bne     1b
2:      
#else
        smovf
#endif

        /* Initialise the contents of the .bss section.  */
        mov     #__bssstart, r1
        mov     #0, r2
        mov     #__bsssize, r3
        sstr.l

        /* Initialize data pointer register(s).
           Note: The registers used here should agree with the definition of
           GP_BASE_REGNUM in gcc/config/rx/rx.h.
           Note: We are assuming that -mint-register has not been used when
           compiling the application.  */
#ifdef _RX_PID
        /* Initialise the constant data pointer and small data pointers.  */
        mov     #__pid_base, r13
        mov     #__gp, r12
#else
        /* Initialise the small data area pointer.  */
        mov     #__gp, r13
#endif
        
        bsr.a   __rx_init

#ifdef PROFILE_SUPPORT  /* Defined in gcrt0.S.  */
        mov     # _start, r1
        mov     # _etext, r2
        bsr.a   __monstartup
#endif

        mov     #0, r1 /* argc */
        mov     #0, r2 /* argv */
        mov     #0, r3 /* envv */
        bsr.a   _main
.LFE2:

#ifdef PROFILE_SUPPORT
        mov      r1, r13       ; Save return code.
        bsr.a   __mcleanup
        mov     r13, r1
#endif

        bsr.a   _exit

        .global _rx_run_preinit_array
        .type   _rx_run_preinit_array,@function
_rx_run_preinit_array:
        mov     #__preinit_array_start,r1
        mov     #__preinit_array_end,r2
        bra.a   _rx_run_inilist

        .global _rx_run_init_array
        .type   _rx_run_init_array,@function
_rx_run_init_array:
        mov     #__init_array_start,r1
        mov     #__init_array_end,r2
        mov     #4, r3
        bra.a   _rx_run_inilist

        .global _rx_run_fini_array
        .type   _rx_run_fini_array,@function
_rx_run_fini_array:
        mov     #__fini_array_start,r2
        mov     #__fini_array_end,r1
        mov     #-4, r3
        /* fall through */

_rx_run_inilist:
next_inilist:
        cmp     r1,r2
        beq.b   done_inilist
        mov.l   [r1],r4
        cmp     #-1, r4
        beq.b   skip_inilist
        cmp     #0, r4
        beq.b   skip_inilist
        pushm   r1-r3
        jsr     r4
        popm    r1-r3
skip_inilist:
        add     r3,r1
        bra.b   next_inilist
done_inilist:
        rts

        .section        .init,"ax"

        .global __rx_init
__rx_init:

        .section        .fini,"ax"

        .global __rx_fini
__rx_fini:
        bsr.a   _rx_run_fini_array

        .section .rodata
        .balign 4
        .global __pid_base
        .weak   __pid_base
__pid_base:   

        .section .sdata
        .balign 4
        .global __gp
        .weak   __gp
__gp:   

        .section .data
        .global ___dso_handle
        .weak   ___dso_handle
___dso_handle:
        .long   0

;;; Provide Dwarf unwinding information that will help GDB stop
;;; backtraces at the right place.  This is stolen from assembly
;;; code generated by GCC with -dA.
        .section        .debug_frame,"",@progbits
.Lframe0:
        .4byte  .LECIE0-.LSCIE0 ; Length of Common Information Entry
.LSCIE0:
        .4byte  0xffffffff      ; CIE Identifier Tag
        .byte   0x1     ; CIE Version
        .ascii "\0"     ; CIE Augmentation
        .uleb128 0x1    ; CIE Code Alignment Factor
        .sleb128 -1     ; CIE Data Alignment Factor
        .byte   0xd     ; CIE RA Column
        .byte   0xc     ; DW_CFA_def_cfa
        .uleb128 0xc
        .uleb128 0x3
        .byte   0x8d    ; DW_CFA_offset, column 0xd
        .uleb128 0x3
        .p2align 2
.LECIE0:
.LSFDE0:
        .4byte  .LEFDE0-.LASFDE0        ; FDE Length
.LASFDE0:
        .4byte  .Lframe0        ; FDE CIE offset
        .4byte  .LFB2           ; FDE initial location
        .4byte  .LFE2-.LFB2     ; FDE address range
        .byte   0xf             ; DW_CFA_def_cfa_expression
        .uleb128 1              ; length of expression
        .byte   0x30            ; DW_OP_lit0
        .p2align 2
.LEFDE0:

        .text