src/Unix/asm_support.s

/*
 *  asm_support.s - Utility functions in assembly language (for native 68k support)
 *
 *  Basilisk II (C) 1997-2001 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

                .file   "asm_support.s"
                .text

                .globl  _m68k_sync_icache
                .globl  _Start680x0__Fv
                .globl  _SetInterruptFlag__FUi
                .globl  _ClearInterruptFlag__FUi
                .globl  _Execute68k
                .globl  _Execute68kTrap
                .globl  _EmulOpTrampoline

                .globl  _RAMBaseHost
                .globl  _ROMBaseHost
                .globl  _EmulOp__FUsP13M68kRegisters
                .globl  _EmulatedSR
                .globl  _InterruptFlags
                .globl  _TriggerInterrupt__Fv


/*
 *  Call m68k_sync_icache() (NetBSD, the version in libm68k is broken)
 */

                .type   _m68k_sync_icache,@function
_m68k_sync_icache:
                movl    sp@(8),d1
                movl    sp@(4),a1
                movl    #0x80000004,d0
                trap    #12
                rts


/*
 *  Jump to Mac ROM, start emulation
 */

                .type   _Start680x0__Fv,@function
_Start680x0__Fv:
                movl    _RAMBaseHost,a0
                addl    #0x8000,a0
                movl    a0,sp
                movl    _ROMBaseHost,a0
                lea     a0@(0x2a),a0
                jmp     a0@


/*
 *  Set/clear interrupt flag (atomically)
 */

                .type   _SetInterruptFlag__FUi,@function
_SetInterruptFlag__FUi:
                movl    sp@(4),d0
                orl     d0,_InterruptFlags
                rts

                .type   _ClearInterruptFlag__FUi,@function
_ClearInterruptFlag__FUi:
                movl    sp@(4),d0
                notl    d0
                andl    d0,_InterruptFlags
                rts


/*
 *  Execute 68k subroutine (must be ended with rts)
 *  r->a[7] and r->sr are unused!
 */

/* void Execute68k(uint32 addr, M68kRegisters *r); */
                .type   _Execute68k,@function
_Execute68k:    movl    sp@(4),d0               |Get arguments
                movl    sp@(8),a0

                movml   d2-d7/a2-a6,sp@-        |Save registers

                movl    a0,sp@-                 |Push pointer to M68kRegisters on stack
                pea     exec68kret              |Push return address on stack
                movl    d0,sp@-                 |Push pointer to 68k routine on stack
                movml   a0@,d0-d7/a0-a6         |Load registers from M68kRegisters

                rts                             |Jump into 68k routine

exec68kret:     movl    a6,sp@-                 |Save a6
                movl    sp@(4),a6               |Get pointer to M68kRegisters
                movml   d0-d7/a0-a5,a6@         |Save d0-d7/a0-a5 to M68kRegisters
                movl    sp@+,a6@(56)            |Save a6 to M68kRegisters
                addql   #4,sp                   |Remove pointer from stack

                movml   sp@+,d2-d7/a2-a6        |Restore registers
                rts


/*
 *  Execute MacOS 68k trap
 *  r->a[7] and r->sr are unused!
 */

/* void Execute68kTrap(uint16 trap, M68kRegisters *r); */
                .type   _Execute68kTrap,@function
_Execute68kTrap:
                movl    sp@(4),d0               |Get arguments
                movl    sp@(8),a0

                movml   d2-d7/a2-a6,sp@-        |Save registers

                movl    a0,sp@-                 |Push pointer to M68kRegisters on stack
                movw    d0,sp@-                 |Push trap word on stack
                subql   #8,sp                   |Create fake A-Line exception frame
                movml   a0@,d0-d7/a0-a6         |Load registers from M68kRegisters

                movl    a2,sp@-                 |Save a2 and d2
                movl    d2,sp@-
                lea     exectrapret,a2          |a2 points to return address
                movw    sp@(16),d2              |Load trap word into d2

                jmp     zpc@(0x28:w)@(10)       |Jump into MacOS A-Line handler

exectrapret:    movl    a6,sp@-                 |Save a6
                movl    sp@(6),a6               |Get pointer to M68kRegisters
                movml   d0-d7/a0-a5,a6@         |Save d0-d7/a0-a5 to M68kRegisters
                movl    sp@+,a6@(56)            |Save a6 to M68kRegisters
                addql   #6,sp                   |Remove pointer and trap word from stack

                movml   sp@+,d2-d7/a2-a6        |Restore registers
                rts


/*
 *  Call EmulOp() after return from SIGILL handler, registers are pushed on stack
 */

                .type   _EmulOpTrampoline,@function
_EmulOpTrampoline:
                movl    sp,a0                   |Get pointer to registers

                movw    _EmulatedSR,d0          |Save EmulatedSR, disable interrupts
                movw    d0,sp@-
                oriw    #0x0700,d0
                movw    d0,_EmulatedSR

                movl    a0,sp@-                 |Push pointer to registers
                movl    a0@(66),a1              |Get saved PC
                addql   #2,a0@(66)              |Skip EMUL_OP opcode
                movw    a1@,sp@-                |Push opcode word
                clrw    sp@-
                jbsr    _EmulOp__FUsP13M68kRegisters
                addql   #8,sp

                movw    sp@+,d0                 |Restore interrupts, trigger pending interrupt
                movw    d0,_EmulatedSR
                andiw   #0x0700,d0
                bne     eot1
                tstl    _InterruptFlags
                beq     eot1
                jbsr    _TriggerInterrupt__Fv

eot1:           moveml  sp@+,d0-d7/a0-a6        |Restore registers
                addql   #4,sp                   |Skip saved SP
                rtr
Revision:	1.4
Committed:	2001-07-14T15:02:47Z (23 years, 4 months ago) by cebix
Branch:	MAIN
Changes since 1.3:	+2 -2 lines
Log Message:	- 1-bit mode under X11 always uses default visual - fixed possible crash in driver_window dtor (image data would be freed twice, once by XDestroyImage() and once in driver_base dtor) - fixed compilation problems with banked memory - fixed typos
#	User	Rev	Content
1	cebix	1.1	/*
2	cebix	1.4	* asm_support.s - Utility functions in assembly language (for native 68k support)
3	cebix	1.1	*
4	cebix	1.4	* Basilisk II (C) 1997-2001 Christian Bauer
5	cebix	1.1	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19			*/
20
21			.file "asm_support.s"
22			.text
23
24			.globl _m68k_sync_icache
25			.globl _Start680x0__Fv
26			.globl _SetInterruptFlag__FUi
27			.globl _ClearInterruptFlag__FUi
28			.globl _Execute68k
29			.globl _Execute68kTrap
30			.globl _EmulOpTrampoline
31
32			.globl _RAMBaseHost
33			.globl _ROMBaseHost
34			.globl _EmulOp__FUsP13M68kRegisters
35			.globl _EmulatedSR
36			.globl _InterruptFlags
37			.globl _TriggerInterrupt__Fv
38
39
40			/*
41			* Call m68k_sync_icache() (NetBSD, the version in libm68k is broken)
42			*/
43
44			.type _m68k_sync_icache,@function
45			_m68k_sync_icache:
46			movl sp@(8),d1
47			movl sp@(4),a1
48			movl #0x80000004,d0
49			trap #12
50			rts
51
52
53			/*
54			* Jump to Mac ROM, start emulation
55			*/
56
57			.type _Start680x0__Fv,@function
58			_Start680x0__Fv:
59			movl _RAMBaseHost,a0
60			addl #0x8000,a0
61			movl a0,sp
62			movl _ROMBaseHost,a0
63			lea a0@(0x2a),a0
64			jmp a0@
65
66
67			/*
68			* Set/clear interrupt flag (atomically)
69			*/
70
71			.type _SetInterruptFlag__FUi,@function
72			_SetInterruptFlag__FUi:
73			movl sp@(4),d0
74			orl d0,_InterruptFlags
75			rts
76
77			.type _ClearInterruptFlag__FUi,@function
78			_ClearInterruptFlag__FUi:
79			movl sp@(4),d0
80			notl d0
81			andl d0,_InterruptFlags
82			rts
83
84
85			/*
86			* Execute 68k subroutine (must be ended with rts)
87			* r->a[7] and r->sr are unused!
88			*/
89
90			/* void Execute68k(uint32 addr, M68kRegisters r); /
91			.type _Execute68k,@function
92			_Execute68k: movl sp@(4),d0 \|Get arguments
93			movl sp@(8),a0
94
95			movml d2-d7/a2-a6,sp@- \|Save registers
96
97			movl a0,sp@- \|Push pointer to M68kRegisters on stack
98			pea exec68kret \|Push return address on stack
99			movl d0,sp@- \|Push pointer to 68k routine on stack
100			movml a0@,d0-d7/a0-a6 \|Load registers from M68kRegisters
101
102			rts \|Jump into 68k routine
103
104			exec68kret: movl a6,sp@- \|Save a6
105			movl sp@(4),a6 \|Get pointer to M68kRegisters
106			movml d0-d7/a0-a5,a6@ \|Save d0-d7/a0-a5 to M68kRegisters
107			movl sp@+,a6@(56) \|Save a6 to M68kRegisters
108			addql #4,sp \|Remove pointer from stack
109
110			movml sp@+,d2-d7/a2-a6 \|Restore registers
111			rts
112
113
114			/*
115			* Execute MacOS 68k trap
116			* r->a[7] and r->sr are unused!
117			*/
118
119			/* void Execute68kTrap(uint16 trap, M68kRegisters r); /
120			.type _Execute68kTrap,@function
121			_Execute68kTrap:
122			movl sp@(4),d0 \|Get arguments
123			movl sp@(8),a0
124
125			movml d2-d7/a2-a6,sp@- \|Save registers
126
127			movl a0,sp@- \|Push pointer to M68kRegisters on stack
128			movw d0,sp@- \|Push trap word on stack
129			subql #8,sp \|Create fake A-Line exception frame
130			movml a0@,d0-d7/a0-a6 \|Load registers from M68kRegisters
131
132			movl a2,sp@- \|Save a2 and d2
133			movl d2,sp@-
134			lea exectrapret,a2 \|a2 points to return address
135			movw sp@(16),d2 \|Load trap word into d2
136
137			jmp zpc@(0x28:w)@(10) \|Jump into MacOS A-Line handler
138
139			exectrapret: movl a6,sp@- \|Save a6
140			movl sp@(6),a6 \|Get pointer to M68kRegisters
141			movml d0-d7/a0-a5,a6@ \|Save d0-d7/a0-a5 to M68kRegisters
142			movl sp@+,a6@(56) \|Save a6 to M68kRegisters
143			addql #6,sp \|Remove pointer and trap word from stack
144
145			movml sp@+,d2-d7/a2-a6 \|Restore registers
146			rts
147
148
149			/*
150			* Call EmulOp() after return from SIGILL handler, registers are pushed on stack
151			*/
152
153			.type _EmulOpTrampoline,@function
154			_EmulOpTrampoline:
155			movl sp,a0 \|Get pointer to registers
156
157			movw _EmulatedSR,d0 \|Save EmulatedSR, disable interrupts
158			movw d0,sp@-
159			oriw #0x0700,d0
160			movw d0,_EmulatedSR
161
162			movl a0,sp@- \|Push pointer to registers
163			movl a0@(66),a1 \|Get saved PC
164			addql #2,a0@(66) \|Skip EMUL_OP opcode
165			movw a1@,sp@- \|Push opcode word
166			clrw sp@-
167			jbsr _EmulOp__FUsP13M68kRegisters
168			addql #8,sp
169
170			movw sp@+,d0 \|Restore interrupts, trigger pending interrupt
171			movw d0,_EmulatedSR
172			andiw #0x0700,d0
173			bne eot1
174			tstl _InterruptFlags
175			beq eot1
176			jbsr _TriggerInterrupt__Fv
177
178			eot1: moveml sp@+,d0-d7/a0-a6 \|Restore registers
179			addql #4,sp \|Skip saved SP
180			rtr