@ vim:filetype=armasm
-@ SekRunPS runs PicoCpu and PicoCpuS68k interleaved in steps of PS_STEP_M68K
+@ SekRunPS runs PicoCpuCM68k and PicoCpuCS68k interleaved in steps of PS_STEP_M68K
@ cycles. This is done without calling CycloneRun and jumping directly to
@ Cyclone code to avoid pushing/popping all the registers every time.
@ .extern is ignored by gas, we add these here just to see what we depend on.
.extern CycloneJumpTab
.extern CycloneDoInterrupt
-.extern PicoCpu
-.extern PicoCpuS68k
+.extern PicoCpuCM68k
+.extern PicoCpuCS68k
.extern SekCycleAim
.extern SekCycleCnt
.extern SekCycleAimS68k
.global SekRunPS @ cyc_m68k, cyc_s68k
SekRunPS:
- stmfd sp!, {r4-r11,lr}
+ stmfd sp!, {r4-r8,r10,r11,lr}
sub sp, sp, #2*4 @ sp[0] = main_cycle_cnt, sp[4] = run_cycle_cnt
@ override CycloneEnd for both contexts
- ldr r7, =PicoCpu
- ldr lr, =PicoCpuS68k
+ ldr r7, =PicoCpuCM68k
+ ldr lr, =PicoCpuCS68k
ldr r2, =CycloneEnd_M68k
ldr r3, =CycloneEnd_S68k
- str r2, [r7,#0x54]
- str r3, [lr,#0x54]
+ str r2, [r7,#0x98]
+ str r3, [lr,#0x98]
@ update aims
ldr r8, =SekCycleAim
- ldr r9, =SekCycleAimS68k
+ ldr r10,=SekCycleAimS68k
ldr r2, [r8]
- ldr r3, [r9]
+ ldr r3, [r10]
add r2, r2, r0
add r3, r3, r1
str r2, [r8]
- str r3, [r9]
+ str r3, [r10]
+ ldr r6, =CycloneJumpTab
ldr r1, =SekCycleCnt
ldr r0, =((488<<16)-PS_STEP_M68K)
- ldr r6, =CycloneJumpTab
+ str r6, [r7,#0x54]
+ str r6, [lr,#0x54] @ make copies to avoid literal pools
@ schedule m68k for the first time..
ldr r1, [r1]
ldr r0, [sp,#4] @ run_cycle_cnt
ldr r1, [r3]
str r4, [r7,#0x40] ;@ Save Current PC + Memory Base
- strb r9, [r7,#0x46] ;@ Save Flags (NZCV)
+ strb r10,[r7,#0x46] ;@ Save Flags (NZCV)
sub r0, r0, r5 @ subtract leftover cycles (which should be negative)
add r0, r0, r1
str r0, [r3]
schedule_s68k:
ldr r8, =SekCycleCntS68k
- ldr r9, =SekCycleAimS68k
+ ldr r10,=SekCycleAimS68k
ldr r3, [sp]
ldr r8, [r8]
- ldr r9, [r9]
+ ldr r10,[r10]
- sub r0, r9, r8
- add r3, r3, r3, asr #1
- add r3, r3, r3, asr #3 @ cycn_s68k = (cycn + cycn/2 + cycn/8)
+ sub r0, r10, r8
+ mov r2, r3
+ add r3, r3, r2, asr #1
+ add r3, r3, r2, asr #3 @ cycn_s68k = (cycn + cycn/2 + cycn/8)
subs r5, r0, r3, asr #16
ble schedule_m68k @ s68k has not enough cycles
- ldr r7, =PicoCpuS68k
+ ldr r7, =PicoCpuCS68k
str r5, [sp,#4] @ run_cycle_cnt
b CycloneRunLocal
ldr r0, [sp,#4] @ run_cycle_cnt
ldr r1, [r3]
str r4, [r7,#0x40] ;@ Save Current PC + Memory Base
- strb r9, [r7,#0x46] ;@ Save Flags (NZCV)
+ strb r10,[r7,#0x46] ;@ Save Flags (NZCV)
sub r0, r0, r5 @ subtract leftover cycles (should be negative)
add r0, r0, r1
str r0, [r3]
ldr r1, =PS_STEP_M68K
ldr r3, [sp] @ main_cycle_cnt
ldr r8, =SekCycleCnt
- ldr r9, =SekCycleAim
+ ldr r10,=SekCycleAim
subs r3, r3, r1
bmi SekRunPS_end
ldr r8, [r8]
- ldr r9, [r9]
+ ldr r10,[r10]
str r3, [sp] @ update main_cycle_cnt
- sub r0, r9, r8
+ sub r0, r10, r8
subs r5, r0, r3, asr #16
ble schedule_s68k @ m68k has not enough cycles
- ldr r7, =PicoCpu
+ ldr r7, =PicoCpuCM68k
str r5, [sp,#4] @ run_cycle_cnt
b CycloneRunLocal
SekRunPS_end:
- ldr r7, =PicoCpu
- ldr lr, =PicoCpuS68k
+ ldr r7, =PicoCpuCM68k
+ ldr lr, =PicoCpuCS68k
mov r0, #0
- str r0, [r7,#0x54] @ remove CycloneEnd handler
- str r0, [lr,#0x54]
+ str r0, [r7,#0x98] @ remove CycloneEnd handler
+ str r0, [lr,#0x98]
@ return
add sp, sp, #2*4
- ldmfd sp!, {r4-r11,pc}
-
+ ldmfd sp!, {r4-r8,r10,r11,pc}
;@ r6 = Opcode Jump table
;@ r7 = Pointer to Cpu Context
;@ r8 = Current Opcode
- ldrb r9,[r7,#0x46] ;@ r9 = Flags (NZCV)
- ldr r0,[r7,#0x44]
- mov r9,r9,lsl #28 ;@ r9 = Flags 0xf0000000, cpsr format
- ;@ r10 = Source value / Memory Base
+ ldrb r10,[r7,#0x46];@ r10 = Flags (NZCV)
+ ldr r1,[r7,#0x44] ;@ get SR high and IRQ level
+ orr r10,r10,r10,lsl #28 ;@ r10 = Flags 0xf0000000, cpsr format
;@ CheckInterrupt:
- movs r0,r0,lsr #24 ;@ Get IRQ level
+ movs r0,r1,lsr #24 ;@ Get IRQ level
beq NoIntsLocal
cmp r0,#6 ;@ irq>6 ?
- ldrleb r1,[r7,#0x44] ;@ Get SR high: T_S__III
andle r1,r1,#7 ;@ Get interrupt mask
cmple r0,r1 ;@ irq<=6: Is irq<=mask ?
- blgt CycloneDoInterrupt
-;@ Check if interrupt used up all the cycles:
- subs r5,r5,#0
- ldrlt r1,[r7,#0x54]
- bxlt r1 ;@ jump to alternative CycloneEnd
+ bgt CycloneDoInterrupt
NoIntsLocal:
-;@ Check if our processor is in stopped state and jump to opcode handler if not
- ldr r0,[r7,#0x58]
+;@ Check if our processor is in special state
+;@ and jump to opcode handler if not
+ ldr r0,[r7,#0x58] ;@ state_flags
ldrh r8,[r4],#2 ;@ Fetch first opcode
- tst r0,r0 ;@ stopped?
+ tst r0,#0x03 ;@ special state?
+ andeq r10,r10,#0xf0000000
ldreq pc,[r6,r8,asl #2] ;@ Jump to opcode handler
- @ stopped
- ldr r1,[r7,#0x54]
+CycloneSpecial2:
+ tst r0,#2 ;@ tracing?
+ bne CycloneDoTrace
+;@ stopped or halted
+ sub r4,r4,#2
+ ldr r1,[r7,#0x98]
mov r5,#0
bx r1