| ------------------------------------------------------------------------------
| jumpto.s -- miscellaneous ROMP support functions
| Version 4 -- 1987-10-14 -- D.N. Lynx Crowe

|	WARNING:
|	--------
|		These functions, in general, assume supervisor mode and
|		'sane' arguments, so no error checking is done.

|	halt()

|		Brings the processor to a grinding halt.  Requires external
|		reset to restart things.  Use only for catastrophic hard halts.

|	jumpto(addr)
|	long addr;

|		Jumps to 'addr'.  No error check is done on 'addr'.

|	rjumpto(addr)
|	long addr;

|		Performs the 68000 'RESET' command, then jumps to 'addr'.
|		No error check is made on 'addr'.

|	sjumpto(addr, stack)
|	long addr, stack;

|		Sets a7 to 'stack', then jumps to 'addr'.
|		No error check is done on 'addr'.

|	xreset()

|		Performs the 68000 'RESET' command.  This is very dangerous,
|		and should be used with extreme care regarding such
|		things as interrupts, device initialization, vectors,
|		and sundry other reset-related things.

| ------------------------------------------------------------------------------
		.text

		.xdef	halt,jumpto,rjumpto,sjumpto,xreset

		.page

halt:		stop	#0x2700			| stop dead, interrupts disabled
		jmp	halt			| stay stopped if stepped thru

jumpto:		movea.l	4(a7),a0		| get jump address
		jmp	(a0)			| go to the jump address

rjumpto:	reset				| reset external devices
		movea.l	4(a7),a0		| get jump address
		jmp	(a0)			| go to the jump address

sjumpto:	movea.l	4(a7),a0		| get jump address
		movea.l	8(a7),a7		| set stack pointer
		jmp	(a0)			| go to the jump address

xreset:		reset				| reset external devices
		rts				| return to caller

		.end