[3ae31e9] | 1 | * ------------------------------------------------------------------------------
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| 2 | * jumpto.s -- miscellaneous ROMP support functions
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| 3 | * Version 4 -- 1987-10-14 -- D.N. Lynx Crowe
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| 4 | *
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| 5 | * WARNING:
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| 6 | * --------
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| 7 | * These functions, in general, assume supervisor mode and
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| 8 | * 'sane' arguments, so no error checking is done.
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| 9 | *
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| 10 | * halt()
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| 11 | *
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| 12 | * Brings the processor to a grinding halt. Requires external
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| 13 | * reset to restart things. Use only for catastrophic hard halts.
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| 14 | *
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| 15 | * jumpto(addr)
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| 16 | * long addr;
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| 17 | *
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| 18 | * Jumps to 'addr'. No error check is done on 'addr'.
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| 19 | *
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| 20 | * rjumpto(addr)
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| 21 | * long addr;
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| 22 | *
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| 23 | * Performs the 68000 'RESET' command, then jumps to 'addr'.
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| 24 | * No error check is made on 'addr'.
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| 25 | *
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| 26 | * sjumpto(addr, stack)
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| 27 | * long addr, stack;
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| 28 | *
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| 29 | * Sets a7 to 'stack', then jumps to 'addr'.
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| 30 | * No error check is done on 'addr'.
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| 31 | *
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| 32 | * xreset()
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| 33 | *
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| 34 | * Performs the 68000 'RESET' command. This is very dangerous,
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| 35 | * and should be used with extreme care regarding such
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| 36 | * things as interrupts, device initialization, vectors,
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| 37 | * and sundry other reset-related things.
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| 38 | *
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| 39 | * ------------------------------------------------------------------------------
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| 40 | .text
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| 41 | *
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| 42 | .xdef _halt,_jumpto,_rjumpto,_sjumpto,_xreset
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| 43 | *
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| 44 | .page
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| 45 | *
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| 46 | _halt: stop #$2700 * stop dead, interrupts disabled
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| 47 | jmp _halt * stay stopped if stepped thru
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| 48 | *
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| 49 | _jumpto: movea.l 4(a7),a0 * get jump address
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| 50 | jmp (a0) * go to the jump address
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| 51 | *
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| 52 | _rjumpto: reset * reset external devices
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| 53 | movea.l 4(a7),a0 * get jump address
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| 54 | jmp (a0) * go to the jump address
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| 55 | *
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| 56 | _sjumpto: movea.l 4(a7),a0 * get jump address
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| 57 | movea.l 8(a7),a7 * set stack pointer
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| 58 | jmp (a0) * go to the jump address
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| 59 | *
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| 60 | _xreset: reset * reset external devices
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| 61 | rts * return to caller
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| 62 | *
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| 63 | .end
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