88 lines
2.8 KiB
ArmAsm
88 lines
2.8 KiB
ArmAsm
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| $NetBSD: SRT0.S,v 1.1.1.1 1995/02/14 22:56:37 gwr Exp $
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| Copyright (c) 1995 Gordon W. Ross
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| All rights reserved.
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| Redistribution and use in source and binary forms, with or without
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| modification, are permitted provided that the following conditions
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| are met:
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| 1. Redistributions of source code must retain the above copyright
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| notice, this list of conditions and the following disclaimer.
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| 2. Redistributions in binary form must reproduce the above copyright
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| notice, this list of conditions and the following disclaimer in the
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| documentation and/or other materials provided with the distribution.
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| 3. The name of the author may not be used to endorse or promote products
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| derived from this software without specific prior written permission.
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| 4. All advertising materials mentioning features or use of this software
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| must display the following acknowledgement:
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| This product includes software developed by Gordon Ross
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| THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| SRT0.S - Stand-alone Run-Time startup code, part 0
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.file "SRT0.S"
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.text
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.globl start
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start:
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| Check to see if the code is located correctly.
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| This SHOULD do a PC-relative load into a0, but...
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| lea start, a0 | current location (0x4000)
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| XXX - GAS version 1.93 gets the above lea wrong!
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.word 0x41fa
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.word 0xfffe
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| Now force a long (not PC-relative) load to a1 and compare.
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lea start:l, a1 | desired location (LINKADDR)
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cmpl a0, a1
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beqs restart
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| Relocate the code and data to where they belong.
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movl #_edata,d0 | Desired end of program
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subl a1,d0 | Calculate length, round up.
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lsrl #2,d0
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Lcp:
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movl a0@+, a1@+
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dbra d0, Lcp
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| Force a long jump to the relocated code (not pc-relative)
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lea restart:l, a0
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jmp a0@
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restart:
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| now in the relocated code
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| Set up stack (just before relocated text)
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lea start:l, a0
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movl a0, sp
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| Call the run-time startup C code, which will:
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| initialize, call main, call exit
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jsr __start:l
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| If _start returns, fall into abort.
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.globl _abort
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_abort:
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trap #0
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| If abort returns, fall into reset.
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.globl _reset
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_reset:
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reset
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jmp _reset
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| function to get the vector base register
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.globl _getvbr
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_getvbr:
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movc vbr, d0
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rts
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| The end.
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