[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
    and     r3, r0, #0xff000000
    bic     r0, r0, #1
    bics    r2, r0, #0xff000000
    beq     crashed

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

    sub     r1, r1, r3
    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
12da51c2	27	and r3, r0, #0xff000000
	28	bic r0, r0, #1
	29	bics r2, r0, #0xff000000
5e89f0f5	30	beq crashed
	31
	32	ldr r1, [r7, #0x6c] @ read16 map
12da51c2	33	mov r2, r2, lsr #M68K_MEM_SHIFT
5e89f0f5	34	ldr r1, [r1, r2, lsl #2]
	35	movs r1, r1, lsl #1
	36	bcs crashed
	37
12da51c2	38	sub r1, r1, r3
5e89f0f5	39	str r1, [r7, #0x60] @ membase
	40	add r0, r0, r1
	41	bx lr
	42
	43	crashed:
	44	stmfd sp!,{lr}
	45	mov r1, r7
	46	bl cyclone_crashed
	47	ldr r0, [r7, #0x40] @ reload PC + membase
	48	ldmfd sp!,{pc}
	49
	50
	51	cyclone_read8: @ u32 a
	52	cyclone_fetch8:
	53	bic r0, r0, #0xff000000
	54	ldr r1, [r7, #0x68] @ read8 map
	55	mov r2, r0, lsr #M68K_MEM_SHIFT
	56	ldr r1, [r1, r2, lsl #2]
	57	eor r2, r0, #1
	58	movs r1, r1, lsl #1
	59	ldrccb r0, [r1, r2]
	60	bxcc lr
	61	bx r1
	62
	63
	64	cyclone_read16: @ u32 a
	65	cyclone_fetch16:
	66	bic r0, r0, #0xff000000
	67	ldr r1, [r7, #0x6c] @ read16 map
	68	mov r2, r0, lsr #M68K_MEM_SHIFT
	69	ldr r1, [r1, r2, lsl #2]
	70	bic r0, r0, #1
	71	movs r1, r1, lsl #1
	72	ldrcch r0, [r1, r0]
	73	bxcc lr
	74	bx r1
	75
	76
	77	cyclone_read32: @ u32 a
	78	cyclone_fetch32:
	79	bic r0, r0, #0xff000000
	80	ldr r1, [r7, #0x6c] @ read16 map
	81	mov r2, r0, lsr #M68K_MEM_SHIFT
	82	ldr r1, [r1, r2, lsl #2]
	83	bic r0, r0, #1
	84	movs r1, r1, lsl #1
	85	ldrcch r0, [r1, r0]!
	86	ldrcch r1, [r1, #2]
	87	orrcc r0, r1, r0, lsl #16
	88	bxcc lr
	89
	90	stmfd sp!,{r0,r1,lr}
	91	mov lr, pc
	92	bx r1
	93	mov r2, r0, lsl #16
	94	ldmia sp, {r0,r1}
	95	str r2, [sp]
	96	add r0, r0, #2
	97	mov lr, pc
	98	bx r1
	99	ldr r1, [sp]
	100	mov r0, r0, lsl #16
	101	orr r0, r1, r0, lsr #16
	102	ldmfd sp!,{r1,r2,pc}
103
104
105	cyclone_write8: @ u32 a, u8 d
106	bic r0, r0, #0xff000000
107	ldr r2, [r7, #0x74] @ write8 map
108	mov r3, r0, lsr #M68K_MEM_SHIFT
109	ldr r2, [r2, r3, lsl #2]
110	eor r3, r0, #1
111	movs r2, r2, lsl #1
112	strccb r1, [r2, r3]
113	bxcc lr
114	bx r2
115
116
117	cyclone_write16: @ u32 a, u16 d
118	bic r0, r0, #0xff000000
119	ldr r2, [r7, #0x78] @ write16 map
120	mov r3, r0, lsr #M68K_MEM_SHIFT
121	ldr r2, [r2, r3, lsl #2]
122	bic r0, r0, #1
123	movs r2, r2, lsl #1
124	strcch r1, [r2, r0]
125	bxcc lr
126	bx r2
127
128
129	cyclone_write32: @ u32 a, u32 d
130	bic r0, r0, #0xff000000
131	ldr r2, [r7, #0x78] @ write16 map
132	mov r3, r0, lsr #M68K_MEM_SHIFT
133	ldr r2, [r2, r3, lsl #2]
134	bic r0, r0, #1
135	movs r2, r2, lsl #1
136	movcc r3, r1, lsr #16
137	strcch r3, [r2, r0]!
138	strcch r1, [r2, #2]
139	bxcc lr
140
141	stmfd sp!,{r0-r2,lr}
142	mov r1, r1, lsr #16
143	mov lr, pc
144	bx r2
145	ldmfd sp!,{r0-r2,lr}
146	add r0, r0, #2
147	bx r2
148
cff531af	149	@ vim:filetype=armasm