129 lines
2.7 KiB
ArmAsm
129 lines
2.7 KiB
ArmAsm
/* crt0.S -- startup file for hppa.
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*
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* Copyright (c) 1995 Cygnus Support
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*
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* The authors hereby grant permission to use, copy, modify, distribute,
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* and license this software and its documentation for any purpose, provided
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* that existing copyright notices are retained in all copies and that this
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* notice is included verbatim in any distributions. No written agreement,
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* license, or royalty fee is required for any of the authorized uses.
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* Modifications to this software may be copyrighted by their authors
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* and need not follow the licensing terms described here, provided that
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* the new terms are clearly indicated on the first page of each file where
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* they apply.
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*/
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.VERSION "1.0"
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.COPYRIGHT "crt0.o for the PA"
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.DATA
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/*
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* Set up the standard spaces (sections) These definitions come
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* from /lib/pcc_prefix.s.
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*/
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.TEXT
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/*
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* stuff we need that's defined elsewhere.
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*/
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.IMPORT main, CODE
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.IMPORT exit, CODE
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.IMPORT _bss_start, DATA
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.IMPORT _end, DATA
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.IMPORT environ, DATA
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/*
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* start -- set things up so the application will run.
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*
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*/
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.PROC
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.CALLINFO SAVE_SP, FRAME=48
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.EXPORT $START$,ENTRY
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$START$
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/* FIXME: this writes to page zero */
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;; setup the %30 (stack pointer) with some memory
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ldil L%_stack,%r30
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ldo R%_stack(%r30),%r30
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;; we need to set %r27 (global data pointer) here too
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ldil L%$global$,%r27
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ldo R%$global$(%r27),%r27 ; same problem as above
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/*
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* zerobss -- zero out the bss section
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*/
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; load the start of bss
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ldil L%_bss_start,%r4
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ldo R%_bss_start(%r4),%r4
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; load the end of bss
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ldil L%_end,%r5
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ldo R%_end(%r5),%r5
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L$bssloop
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addi -1,%r5,%r5 ; decrement _bss_end
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stb %r0,0(0,%r5) ; we do this by bytes for now even
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; though it's slower, it's safer
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combf,= %r4,%r5, L$bssloop
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nop
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ldi 1,%ret0
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/*
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* Call the main routine from the application to get it going.
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* main (argc, argv, environ)
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* We pass argv as a pointer to NULL.
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*/
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ldil L%main,%r22
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ble R%main(%sr4,%r22)
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copy %r31,%r2
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/*
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* Call exit() from the C library with the return value from main()
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*/
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copy %r28,%r26
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ldil L%exit,%r22
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ble R%exit(%sr4,%r22)
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copy %r31,%r2
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.PROCEND
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/*
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* _exit -- Exit from the application. Normally we cause a user trap
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* to return to the ROM monitor for another run.
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*/
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.EXPORT _exit, ENTRY
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_exit
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.PROC
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.CALLINFO
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.ENTRY
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;; This just causes a breakpoint exception
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break 0x0,0x0
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bv,n (%rp)
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nop
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.EXIT
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.PROCEND
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/*
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* _sr4export -- support for called functions. (mostly for GDB)
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*/
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.EXPORT _sr4export, ENTRY
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_sr4export:
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.PROC
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.CALLINFO
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.ENTRY
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ble 0(%sr4,%r22)
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copy %r31,%rp
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ldw -24(%sr0,%sp),%rp
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ldsid (%sr0,%rp),%r1
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mtsp %r1,%sr0
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be,n 0(%sr0,%rp)
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nop
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.EXIT
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.PROCEND
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