source: trunk/libs/newlib/src/libgloss/hp74x/crt0.s @ 495

/*
 * crt0.S -- startup file for hppa.
 *              rob@cygnus.com (Rob Savoye)
 */
        .VERSION "0.2"
        .COPYRIGHT "crt0.S for hppa"

;sp      .equ    %r30                   ; stack pointer
;dp      .equ    %r27                   ; global data pointer
;arg0    .equ    %r26                   ; argument
;arg1    .equ    %r25                   ; argument or high part of double argument
;arg2    .equ    %r24                   ; argument
;arg3    .equ    %r23                   ; argument or high part of double argument

#define         IMM(a,b)        ldil L%a,b  ! ldo  R%a(b),b
#define         imm(i,t)        ldil LS%i,t ! addi RS%i,t,t

        .DATA

/****
 * FIXME: these are just a gross hack so this will assemble
 ****/
_bss_start      .WORD
_bss_end        .WORD
_foobar 
                .STRINGZ "Foo Bar...\r\n"

;;_SYSTEM_ID    .WORD
;;              .EXPORT _SYSTEM_ID      ; FIXME this is only so it'll
                                        ; link
        
/* 
 * Set up the standard spaces (sections) These definitions come
 * from /lib/pcc_prefix.s.
 */
        .space  $TEXT$,0
        
        .SUBSPA $BOOT$,QUAD=0,ALIGN=8,ACCESS=0x2c,SORT=4
        .IMPORT _start

/*
 * stuff we need that's defined elsewhere.
 */
        .IMPORT main, CODE
        .IMPORT _bss_start, DATA
        .IMPORT _bss_end, DATA
        .IMPORT environ, DATA

/*
 * start -- set things up so the application will run.
 *
 */
        .PROC
        .CALLINFO SAVE_SP, FRAME=48
        .EXPORT $START$,ENTRY
$START$

        /* FIXME: this writes to page zero */
        ;; setup the %30 (stack pointer) with some memory
        ldil    L%_stack+48,%r30
        ldo     R%_stack+48(%r30),%r30          ; should be %r30 (sp) but then
                                                ; we'd kill our test program :-)
        ;; we need to set %r27 (global data pointer) here too 
        ldil    L%$global$,%r27
        ldo     R%$global$(%r27),%r27           ; same problem as above

/*
 * zerobss -- zero out the bss section
 */
        ; load the start of bss
        ldil    L%_bss_start,%r4
        ldo     R%_bss_start(%r4),%r4

        ;  load the end of bss
        ldil    L%_bss_end,%r5
        ldo     R%_bss_end(%r5),%r5


bssloop
        addi    -1,%r5,%r5                      ; decrement _bss_end
        stb     %r0,0(0,%r5)                    ; we do this by bytes for now even
                                                ; though it's slower, it's safer
        combf,= %r4,%r5, bssloop        
        nop
        
        ldi     1,%ret0

/*
 * Call the main routine from the application to get it going.
 * main (argc, argv, environ)
 * We pass argv as a pointer to NULL.
 */

        bl      main,%r2
        nop

        .PROCEND
/*
 * _exit -- Exit from the application. Normally we cause a user trap
 *          to return to the ROM monitor for another run, but with
 *          this monitor we can't. Still, "C" wants this symbol, it
 *          should be here. Jumping to 0xF0000004 jumps back into the
 *          firmware, while writing a 5 to 0xFFFE0030 causes a reset.
 */
        .EXPORT _exit, ENTRY
_exit
        .PROC
        .CALLINFO
        .ENTRY
;;      ldil    L%0xf0000004,%r1
;;      bl      %r1, %r2
        
        ldil    L'4026531844,%r19
        ldo     R'4026531844(%r19),%r19
        blr     %r19, %r2
        nop
        
        ;; This just causes a breakpoint exception
;;      break   0x0e,0xa5a
;;      bv,n    (%rp)
        nop
        .EXIT
        .PROCEND

        .subspa $UNWIND_START$,QUAD=0,ALIGN=8,ACCESS=0x2c,SORT=56
        .export $UNWIND_START
$UNWIND_START
        .subspa $UNWIND$,QUAD=0,ALIGN=8,ACCESS=0x2c,SORT=64
        .subspa $UNWIND_END$,QUAD=0,ALIGN=8,ACCESS=0x2c,SORT=72
        .export $UNWIND_END
$UNWIND_END
        .subspa $RECOVER_START$,QUAD=0,ALIGN=4,ACCESS=0x2c,SORT=73
        .export $RECOVER_START
$RECOVER_START
        .subspa $RECOVER$,QUAD=0,ALIGN=4,ACCESS=0x2c,SORT=80
        .subspa $RECOVER_END$,QUAD=0,ALIGN=4,ACCESS=0x2c,SORT=88
        .export $RECOVER_END
$RECOVER_END

; The following declarations are, by default in the data space ($PRIVATE$)

;;        .space  $PRIVATE$,1

/*
 * Here we set up the standard date sub spaces.
 * _dp is for the WinBond board.
 *
 * Set up some room for a stack. We just grab a chunk of memory.
 * We also setup some space for the global variable space, which
 * must be done using the reserved name "$global$" so "C" code
 * can find it. The stack grows towards the higher addresses.
 */

        .subspa $DATA$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=16
        .subspa $SHORTDATA$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=24
        .subspa $GLOBAL$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=40
        .export $global$
        .export _dp
$global$
_dp
        .subspa $SHORTBSS$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=80,ZERO
        .subspa $BSS$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=82,ZERO

       .subspa $STACK$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=88,ZERO
        .export _stack
_stack
        .BLOCK          0x2000

/*
 * The heap follows the stack. To use dynamic memory routines in an
 * application, some space MUST be assigned to the stack.
 */

        .subspa $HEAP$,QUAD=1,ALIGN=8,ACCESS=0x1f,SORT=96,ZERO
        .export _heap
_heap
        .end