Subversion Repositories openrisc_2011-10-31

/* crt0.S -- startup file for frv.

 *

 * Copyright (c) 2002, 2003 Red Hat, Inc

 *

 * The authors hereby grant permission to use, copy, modify, distribute,

 * and license this software and its documentation for any purpose, provided

 * that existing copyright notices are retained in all copies and that this

 * notice is included verbatim in any distributions. No written agreement,

 * license, or royalty fee is required for any of the authorized uses.

 * Modifications to this software may be copyrighted by their authors

 * and need not follow the licensing terms described here, provided that

 * the new terms are clearly indicated on the first page of each file where

 * they apply.

 */

#include 

        /* statically store .Lcall's address so we can see if we are running

           at the location we were linked for or a different location.  */

        .data

        .type   EXT(__start_cmp),@object

        .size   EXT(__start_cmp),4

        .p2align 2

EXT(__start_cmp):

        .picptr  .Lcall

        .globl  __start

        .weak   _start

        .text

        .type   __start,@function

__start:

_start:

        call    .Lcall                          /* set up _gp in a pic-friendly manor */

.Lcall: movsg   lr, gr4

        P(sethi) #gprelhi(.Lcall), gr5

        setlo    #gprello(.Lcall), gr5

        P(sub)   gr4, gr5, gr16

#if ! __FRV_FDPIC__

        sethi    #gprelhi(EXT(_stack)), sp      /* load up stack pointer */

        P(setlo) #gprello(EXT(_stack)), sp

        setlos   #0, fp                         /* zero fp to allow unwinders to stop */

        P(add)   sp, gr16, sp

#define FDPIC(...)

#else

#define FDPIC(...) __VA_ARGS__

        /* The assembler will rightfully claim that

        #hi/lo(__stacksize) are unsafe for PIC, but since __stacksize

        is absolute, and we don't want it to be relocated, we should

        be fine.  */

        sethi   #gprelhi(EXT(__end)), gr6

        P(sethi) #hi(EXT(__stacksize+7)), gr5

        setlo   #gprello(EXT(__end)), gr6

        P(setlo) #lo(EXT(__stacksize+7)), gr5

        add     gr6, gr16, gr6

        add     gr6, gr5, gr5

        andi    gr5, -8, sp

        /* Using GPREL to compute _GLOBAL_OFFSET_TABLE_'s will force

        the entire program to relocate as a unit, which is fine for

        frv-elf.  */

        P(sethi) #gprelhi(EXT(_GLOBAL_OFFSET_TABLE_)), gr15

        setlo    #gprello(EXT(_GLOBAL_OFFSET_TABLE_)), gr15

        /* We compute the value in a call-saved register (that happens

        to be the PIC register in the EABI, and copy it to gr15 before

        every call.  */

        add      gr15, gr16, gr17

#endif

        sethi    #gprelhi(EXT(__start_cmp)), gr5

        setlo    #gprello(EXT(__start_cmp)), gr5

        ld       @(gr5,gr16), gr6

        subcc   gr4, gr6, gr8, icc0

        beq     icc0, 0, .Lfixed

        P(st)   gr4, @(gr5, gr16)       /* update so if we restart no need to fixup */

        setlos  4, gr11

#if ! __FRV_FDPIC__

                                        /* fixup the .ctors list */

        sethi    #gprelhi(EXT(__CTOR_LIST__)), gr9

        P(sethi) #gprelhi(EXT(__CTOR_END__)), gr10

        setlo    #gprello(EXT(__CTOR_LIST__)), gr9

        P(setlo) #gprello(EXT(__CTOR_END__)), gr10

        add      gr9, gr16, gr9

        P(add)   gr10, gr16, gr10

        addi     gr9, 4, gr9

        P(subi)  gr10, 4, gr10

        call     EXT(__frv_fixptrs)

                                        /* fixup the .dtors list */

        P(sethi) #gprelhi(EXT(__DTOR_LIST__)), gr9

        sethi    #gprelhi(EXT(__DTOR_END__)), gr10

        P(setlo) #gprello(EXT(__DTOR_LIST__)), gr9

        setlo    #gprello(EXT(__DTOR_END__)), gr10

        P(add)   gr9, gr16, gr9

        add      gr10, gr16, gr10

        P(addi)  gr9, 4, gr9

        subi     gr10, 4, gr10

        call     EXT(__frv_fixptrs)

#endif /* ! __FRV_FDPIC__ */

                                        /* fixup the user .rofixup list */

        P(sethi) #gprelhi(EXT(__ROFIXUP_LIST__)), gr9

        sethi    #gprelhi(EXT(__ROFIXUP_END__)), gr10

        P(setlo) #gprello(EXT(__ROFIXUP_LIST__)), gr9

        setlo    #gprello(EXT(__ROFIXUP_END__)), gr10

        P(add)   gr9, gr16, gr9

        add      gr10, gr16, gr10

        FDPIC(mov gr17, gr15)

        call     EXT(__frv_fix_usrptrs)

.Lfixed:

/* HSR flags */

#define HSR_ICE  0x80000000             /* Instruction cache enable */

#define HSR_DCE  0x40000000             /* Data cache enable */

#define HSR_CBM  0x08000000             /* Cache copy back mode */

#define HSR_EIMM 0x04000000             /* Enable Instruction MMU */

#define HSR_EDMM 0x02000000             /* Enable Data MMU */

#define HSR_EMEM 0x00800000             /* Enable MMU miss exception mask */

#define HSR_RME  0x00400000             /* Ram mode enable */

#define HSR_SA   0x00001000             /* Start address */

#define HSR_FRN  0x00000800             /* Number of FPRs */

#define HSR_GRN  0x00000400             /* Number of GPRs */

#define HSR_FRHE 0x00000200             /* FR Higher Enable */

#define HSR_FRLE 0x00000100             /* FR Lower Enable */

#define HSR_GRHE 0x00000080             /* GR Higher Enable */

#define HSR_GRLE 0x00000040             /* GR Lower Enable */

#ifndef HSR_CLEAR

#define HSR_CLEAR 0

#endif

#ifndef HSR_SET

#ifndef FRV_NO_CACHE

#define HSR_SET (HSR_ICE|HSR_DCE|HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE)

#else

#define HSR_SET (HSR_FRHE|HSR_FRLE|HSR_GRHE|HSR_GRLE)

#endif

#endif

/* PSR flags */

#define PSR_ICE  0x00010000             /* In circuit emulation mode */

#define PSR_NEM  0x00004000             /* Non-exception mode */

#define PSR_CM   0x00002000             /* Conditional mode */

#define PSR_BE   0x00001000             /* Big endian mode */

#define PSR_EF   0x00000100             /* Enable floating point */

#define PSR_EM   0x00000080             /* Enable media instructions */

#define PSR_S    0x00000004             /* Enable supervisor mode */

#define PSR_PS   0x00000002             /* Previous supervisor mode */

#define PSR_ET   0x00000001             /* Enable interrupts */

#ifndef PSR_CLEAR

#if __FRV_FPR__

#define PSR_CLEAR 0

#else

#define PSR_CLEAR (PSR_EF|PSR_EM)

#endif

#endif

#ifndef PSR_SET

#if __FRV_FPR__

#define PSR_SET (PSR_NEM|PSR_CM|PSR_EF|PSR_EM)

#else

#define PSR_SET (PSR_NEM|PSR_CM)

#endif

#endif

        /* Enable floating point */

        movsg     hsr0, gr4

        P(sethi)  #hi(HSR_SET), gr5

        setlo     #lo(HSR_SET), gr5

        P(sethi)  #hi(~HSR_CLEAR), gr6

        setlo     #lo(~HSR_CLEAR), gr6

        or        gr4, gr5, gr4

        and       gr4, gr6, gr4

        movgs     gr4, hsr0

        movsg     psr, gr4

        P(sethi)  #hi(PSR_SET), gr5

        setlo     #lo(PSR_SET), gr5

        P(sethi)  #hi(~PSR_CLEAR), gr6

        setlo     #lo(~PSR_CLEAR), gr6

        or        gr4, gr5, gr4

        and       gr4, gr6, gr4

        movgs     gr4, psr

        /* zero the bss area */

        P(sethi)  #gprelhi(__bss_start), gr8

        sethi     #gprelhi(__end), gr4

        P(setlo)  #gprello(__bss_start), gr8

        setlo     #gprello(__end), gr4

        P(add)    gr8, gr16, gr8

        add       gr4, gr16, gr4

        P(setlos) #0, gr9

        sub       gr4, gr8, gr10

        FDPIC(mov gr17, gr15)

        call      EXT(memset)

        P(setlos) #0, gr8               /* zero argc, argv, envp */

        setlos    #0, gr9

        P(setlos) #0, gr10

        FDPIC(mov gr17, gr15)

        call      EXT(main)

        FDPIC(mov gr17, gr15)

        call      EXT(exit)

.Lend:

        .size   __start,(.Lend-__start)

#if ! __FRV_FDPIC__

        /* Routine to adjust pointers

           gr8  = difference to adjust by

           gr9  = starting address

           gr10 = ending address + 4

           gr11 = amount to add to the pointer each iteration.  */

        .globl  EXT(__frv_fixptrs)

        .type   EXT(__frv_fixptrs),@function

EXT(__frv_fixptrs):

        P(sub)  gr9, gr11, gr9

        sub     gr10, gr11, gr10

.Lloop2:

        cmp     gr10, gr9, icc0

        bls     icc0, 0, .Lret2

        ldu     @(gr9,gr11), gr5

        add     gr8, gr5, gr5

        P(st)   gr5, @(gr9,gr0)

        bra     .Lloop2

.Lret2: ret

.Lend2:

        .size   EXT(__frv_fixptrs),.Lend2-EXT(__frv_fixptrs)

#endif /* ! __FRV_FDPIC__ */

        /* Routine to adjust statically initialized pointers

           Note since these are pointers to pointers, they

           need to be adjusted themsevles.

           gr8  = difference to adjust by

           gr9  = starting address

           gr10 = ending address + 4

           gr11 = amount to add to the pointer each iteration.  */

        .globl  EXT(__frv_fix_usrptrs)

        .type   EXT(__frv_fix_usrptrs),@function

EXT(__frv_fix_usrptrs):

        P(sub)  gr9, gr11, gr9

        sub     gr10, gr11, gr10

.Lloop3:

        cmp     gr10, gr9, icc0

        bls     icc0, 0, .Lret3

        ldu     @(gr9,gr11), gr5

        ld      @(gr5, gr8), gr6

        cmp     gr6, gr0, icc0          /* skip pointers initialized to 0 */

        beq     icc0, 0, .Lloop3

        add     gr8, gr6, gr6

        P(st)   gr6, @(gr5,gr8)

        bra     .Lloop3

.Lret3: ret

.Lend3:

        .size   EXT(__frv_fix_usrptrs),.Lend2-EXT(__frv_fix_usrptrs)

        .section .data

        .global __dso_handle

        .weak __dso_handle

__dso_handle:

        .long   0