source: buchla-68k/lib700/jumpto.s@ 7bb1284

Last change on this file since 7bb1284 was 4f508e6, checked in by Thomas Lopatic <thomas@…>, 7 years ago

Converted assembly language files.
  • Property mode set to 100644
File size: 1.6 KB
Line 
1| ------------------------------------------------------------------------------
2| jumpto.s -- miscellaneous ROMP support functions
3| Version 4 -- 1987-10-14 -- D.N. Lynx Crowe
4
5| WARNING:
6| --------
7| These functions, in general, assume supervisor mode and
8| 'sane' arguments, so no error checking is done.
9
10| halt()
11
12| Brings the processor to a grinding halt. Requires external
13| reset to restart things. Use only for catastrophic hard halts.
14
15| jumpto(addr)
16| long addr;
17
18| Jumps to 'addr'. No error check is done on 'addr'.
19
20| rjumpto(addr)
21| long addr;
22
23| Performs the 68000 'RESET' command, then jumps to 'addr'.
24| No error check is made on 'addr'.
25
26| sjumpto(addr, stack)
27| long addr, stack;
28
29| Sets a7 to 'stack', then jumps to 'addr'.
30| No error check is done on 'addr'.
31
32| xreset()
33
34| Performs the 68000 'RESET' command. This is very dangerous,
35| and should be used with extreme care regarding such
36| things as interrupts, device initialization, vectors,
37| and sundry other reset-related things.
38
39| ------------------------------------------------------------------------------
40 .text
41
42 .xdef _halt,_jumpto,_rjumpto,_sjumpto,_xreset
43
44 .page
45
46_halt: stop #0x2700 | stop dead, interrupts disabled
47 jmp _halt | stay stopped if stepped thru
48
49_jumpto: movea.l 4(a7),a0 | get jump address
50 jmp (a0) | go to the jump address
51
52_rjumpto: reset | reset external devices
53 movea.l 4(a7),a0 | get jump address
54 jmp (a0) | go to the jump address
55
56_sjumpto: movea.l 4(a7),a0 | get jump address
57 movea.l 8(a7),a7 | set stack pointer
58 jmp (a0) | go to the jump address
59
60_xreset: reset | reset external devices
61 rts | return to caller
62
63 .end
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