mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-10-27 00:29:39 -04:00
149 lines
3.3 KiB
ArmAsm
149 lines
3.3 KiB
ArmAsm
/*
|
|
* 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
|