[picodrive.git] / pico / m68kif_cyclone.s

/*
 * PicoDrive
 * (C) notaz, 2009
 *
 * This work is licensed under the terms of MAME license.
 * See COPYING file in the top-level directory.
 */

.equ M68K_MEM_SHIFT, 16

.global cyclone_checkpc
.global cyclone_fetch8
.global cyclone_fetch16
.global cyclone_fetch32
.global cyclone_read8
.global cyclone_read16
.global cyclone_read32
.global cyclone_write8
.global cyclone_write16
.global cyclone_write32

@ Warning: here we abuse the fact that we are only called
@ from Cyclone, and assume that r7 contains context pointer.
cyclone_checkpc:
    ldr     r1, [r7, #0x60]  @ membase
    sub     r0, r0, r1
    bic     r0, r0, #0xff000000
    bics    r0, r0, #1
    beq     crashed

    ldr     r1, [r7, #0x6c]  @ read16 map
    mov     r2, r0, lsr #M68K_MEM_SHIFT
    ldr     r1, [r1, r2, lsl #2]
    movs    r1, r1, lsl #1
    bcs     crashed

    str     r1, [r7, #0x60]  @ membase
    add     r0, r0, r1
    bx      lr

crashed:
    stmfd   sp!,{lr}
    mov     r1, r7
    bl      cyclone_crashed
    ldr     r0, [r7, #0x40]  @ reload PC + membase
    ldmfd   sp!,{pc}


cyclone_read8: @ u32 a
cyclone_fetch8:
    bic     r0, r0, #0xff000000
    ldr     r1, [r7, #0x68]  @ read8 map
    mov     r2, r0, lsr #M68K_MEM_SHIFT
    ldr     r1, [r1, r2, lsl #2]
    eor     r2, r0, #1
    movs    r1, r1, lsl #1
    ldrccb  r0, [r1, r2]
    bxcc    lr
    bx      r1


cyclone_read16: @ u32 a
cyclone_fetch16:
    bic     r0, r0, #0xff000000
    ldr     r1, [r7, #0x6c]  @ read16 map
    mov     r2, r0, lsr #M68K_MEM_SHIFT
    ldr     r1, [r1, r2, lsl #2]
    bic     r0, r0, #1
    movs    r1, r1, lsl #1
    ldrcch  r0, [r1, r0]
    bxcc    lr
    bx      r1


cyclone_read32: @ u32 a
cyclone_fetch32:
    bic     r0, r0, #0xff000000
    ldr     r1, [r7, #0x6c]  @ read16 map
    mov     r2, r0, lsr #M68K_MEM_SHIFT
    ldr     r1, [r1, r2, lsl #2]
    bic     r0, r0, #1
    movs    r1, r1, lsl #1
    ldrcch  r0, [r1, r0]!
    ldrcch  r1, [r1, #2]
    orrcc   r0, r1, r0, lsl #16
    bxcc    lr

    stmfd   sp!,{r0,r1,lr}
    mov     lr, pc
    bx      r1
    mov     r2, r0, lsl #16
    ldmia   sp, {r0,r1}
    str     r2, [sp]
    add     r0, r0, #2
    mov     lr, pc
    bx      r1
    ldr     r1, [sp]
    mov     r0, r0, lsl #16
    orr     r0, r1, r0, lsr #16
    ldmfd   sp!,{r1,r2,pc}


cyclone_write8: @ u32 a, u8 d
    bic     r0, r0, #0xff000000
    ldr     r2, [r7, #0x74]  @ write8 map
    mov     r3, r0, lsr #M68K_MEM_SHIFT
    ldr     r2, [r2, r3, lsl #2]
    eor     r3, r0, #1
    movs    r2, r2, lsl #1
    strccb  r1, [r2, r3]
    bxcc    lr
    bx      r2


cyclone_write16: @ u32 a, u16 d
    bic     r0, r0, #0xff000000
    ldr     r2, [r7, #0x78]  @ write16 map
    mov     r3, r0, lsr #M68K_MEM_SHIFT
    ldr     r2, [r2, r3, lsl #2]
    bic     r0, r0, #1
    movs    r2, r2, lsl #1
    strcch  r1, [r2, r0]
    bxcc    lr
    bx      r2


cyclone_write32: @ u32 a, u32 d
    bic     r0, r0, #0xff000000
    ldr     r2, [r7, #0x78]  @ write16 map
    mov     r3, r0, lsr #M68K_MEM_SHIFT
    ldr     r2, [r2, r3, lsl #2]
    bic     r0, r0, #1
    movs    r2, r2, lsl #1
    movcc   r3, r1, lsr #16
    strcch  r3, [r2, r0]!
    strcch  r1, [r2, #2]
    bxcc    lr

    stmfd   sp!,{r0-r2,lr}
    mov     r1, r1, lsr #16
    mov     lr, pc
    bx      r2
    ldmfd   sp!,{r0-r2,lr}
    add     r0, r0, #2
    bx      r2

@ vim:filetype=armasm
Commit	Line	Data
cff531af	1	/*
	2	* PicoDrive
	3	* (C) notaz, 2009
	4	*
	5	* This work is licensed under the terms of MAME license.
	6	* See COPYING file in the top-level directory.
	7	*/
5e89f0f5	8
	9	.equ M68K_MEM_SHIFT, 16
	10
	11	.global cyclone_checkpc
	12	.global cyclone_fetch8
	13	.global cyclone_fetch16
	14	.global cyclone_fetch32
	15	.global cyclone_read8
	16	.global cyclone_read16
	17	.global cyclone_read32
	18	.global cyclone_write8
	19	.global cyclone_write16
	20	.global cyclone_write32
	21
	22	@ Warning: here we abuse the fact that we are only called
	23	@ from Cyclone, and assume that r7 contains context pointer.
	24	cyclone_checkpc:
	25	ldr r1, [r7, #0x60] @ membase
	26	sub r0, r0, r1
	27	bic r0, r0, #0xff000000
	28	bics r0, r0, #1
	29	beq crashed
	30
	31	ldr r1, [r7, #0x6c] @ read16 map
	32	mov r2, r0, lsr #M68K_MEM_SHIFT
	33	ldr r1, [r1, r2, lsl #2]
	34	movs r1, r1, lsl #1
	35	bcs crashed
	36
	37	str r1, [r7, #0x60] @ membase
	38	add r0, r0, r1
	39	bx lr
	40
	41	crashed:
	42	stmfd sp!,{lr}
	43	mov r1, r7
	44	bl cyclone_crashed
	45	ldr r0, [r7, #0x40] @ reload PC + membase
	46	ldmfd sp!,{pc}
	47
	48
	49	cyclone_read8: @ u32 a
	50	cyclone_fetch8:
	51	bic r0, r0, #0xff000000
	52	ldr r1, [r7, #0x68] @ read8 map
	53	mov r2, r0, lsr #M68K_MEM_SHIFT
	54	ldr r1, [r1, r2, lsl #2]
	55	eor r2, r0, #1
	56	movs r1, r1, lsl #1
	57	ldrccb r0, [r1, r2]
	58	bxcc lr
	59	bx r1
	60
	61
	62	cyclone_read16: @ u32 a
	63	cyclone_fetch16:
	64	bic r0, r0, #0xff000000
	65	ldr r1, [r7, #0x6c] @ read16 map
	66	mov r2, r0, lsr #M68K_MEM_SHIFT
	67	ldr r1, [r1, r2, lsl #2]
	68	bic r0, r0, #1
	69	movs r1, r1, lsl #1
	70	ldrcch r0, [r1, r0]
	71	bxcc lr
72	bx r1
73
74
75	cyclone_read32: @ u32 a
76	cyclone_fetch32:
77	bic r0, r0, #0xff000000
78	ldr r1, [r7, #0x6c] @ read16 map
79	mov r2, r0, lsr #M68K_MEM_SHIFT
80	ldr r1, [r1, r2, lsl #2]
81	bic r0, r0, #1
82	movs r1, r1, lsl #1
83	ldrcch r0, [r1, r0]!
84	ldrcch r1, [r1, #2]
85	orrcc r0, r1, r0, lsl #16
86	bxcc lr
87
88	stmfd sp!,{r0,r1,lr}
89	mov lr, pc
90	bx r1
91	mov r2, r0, lsl #16
92	ldmia sp, {r0,r1}
93	str r2, [sp]
94	add r0, r0, #2
95	mov lr, pc
96	bx r1
97	ldr r1, [sp]
98	mov r0, r0, lsl #16
99	orr r0, r1, r0, lsr #16
100	ldmfd sp!,{r1,r2,pc}
101
102
103	cyclone_write8: @ u32 a, u8 d
104	bic r0, r0, #0xff000000
105	ldr r2, [r7, #0x74] @ write8 map
106	mov r3, r0, lsr #M68K_MEM_SHIFT
107	ldr r2, [r2, r3, lsl #2]
108	eor r3, r0, #1
109	movs r2, r2, lsl #1
110	strccb r1, [r2, r3]
111	bxcc lr
112	bx r2
113
114
115	cyclone_write16: @ u32 a, u16 d
116	bic r0, r0, #0xff000000
117	ldr r2, [r7, #0x78] @ write16 map
118	mov r3, r0, lsr #M68K_MEM_SHIFT
119	ldr r2, [r2, r3, lsl #2]
120	bic r0, r0, #1
121	movs r2, r2, lsl #1
122	strcch r1, [r2, r0]
123	bxcc lr
124	bx r2
125
126
127	cyclone_write32: @ u32 a, u32 d
128	bic r0, r0, #0xff000000
129	ldr r2, [r7, #0x78] @ write16 map
130	mov r3, r0, lsr #M68K_MEM_SHIFT
131	ldr r2, [r2, r3, lsl #2]
132	bic r0, r0, #1
133	movs r2, r2, lsl #1
134	movcc r3, r1, lsr #16
135	strcch r3, [r2, r0]!
136	strcch r1, [r2, #2]
137	bxcc lr
138
139	stmfd sp!,{r0-r2,lr}
140	mov r1, r1, lsr #16
141	mov lr, pc
142	bx r2
143	ldmfd sp!,{r0-r2,lr}
144	add r0, r0, #2
145	bx r2
146
cff531af	147	@ vim:filetype=armasm