recv_one_byte 1
rts
+# receive 1 16bit word to d0
+# in: a1 - data port
+# trash: d1,d2
+recv_word:
+ recv_one_byte
+ move.b d0,d2
+ recv_one_byte
+ lsl.w #8,d2
+ move.b d0,d2
+ move.w d2,d0
+ rts
+
# receive address/size to d0 (3 bytes BE)
# in: a1 - data port
# trash: d1,d2
move.l d2,d0
rts
+# send 1 byte in d0
+# in: a1 - data port
+# trash: d1,d2
+send_byte:
+ send_one_byte
+ rts
+
+.macro switch_to_output
+0: /*Lwait_tl_low: PC should switch to rx mode before lowering tl */
+ move.b (a1),d0
+ btst.b #4,d0
+ bne 0b /*Lwait_tl_low*/
+
+ move.b #0x4f,(0xa1000b).l
+ move.b #0x40,(a1)
+.endm
+
+.equ sat_maxsize, (80*8+0x200) /* sprites+max_align */
+
+# make sure cache is invalidated
+# note: VRAM copy doesn't seem to help here
+# note2: cache is updated as data is written
+# in: d0 - vdp reg5, a0 = 0xc00000
+# trash: d1,d2,a2
+invalidate_sprite_cache:
+ move.w #0x8f02,4(a0) /* auto increment 2 */
+ lsl.b #1,d0 /* upper byte of sat address */
+ move.b d0,d1
+ lsr.b #6,d1 /* 15:14 dst addr */
+ and.b #0x3f,d0 /* assemble cmd */
+ lsl.w #8,d0
+ swap d0
+ move.b d1,d0
+ move.l d0,4(a0)
+
+ move.l #0xffe000,a2
+ move.l #sat_maxsize/2-1,d2
+0:
+ move.w (a0),(a2)+
+ dbra d2,0b
+
+ bset #30,d0 /* VRAM write */
+ move.l d0,4(a0)
+
+ move.l #0xffe000,a2
+ move.l #sat_maxsize/2-1,d2
+0:
+ move.w (a2)+,(a0)
+ dbra d2,0b
+ rts
+
+
do_transfer:
lea 0xa10005,a1
bra pcc_transfer_recv /* sent to us */
bra pcc_transfer_send /* recv from us */
bra pcc_jump
+ bra pcc_io
+ bra pcc_loadstate
+ bra pcc_vram_send
bra pcc_test_code
+/* receive data from PC */
pcc_transfer_recv:
bsr recv_ad
move.l d0,a0
bra return
+/* send data to PC */
pcc_transfer_send:
bsr recv_ad
move.l d0,a0
bsr recv_ad
move.l d0,d3
-0: /*Lwait_tl_low:*/
- move.b (a1),d0
- btst.b #4,d0
- bne 0b /*Lwait_tl_low*/
-
- move.b #0x4f,(0xa1000b).l
- move.b #0x40,(a1)
+ switch_to_output
tr_send_loop:
move.b (a0)+,d0
bra return
+/* call specified location */
pcc_jump:
bsr recv_ad
move.l d0,a0
- jmp (a0)
+ jsr (a0)
+ bra return
+
+/* do simple i/o commands */
+pcc_io:
+ moveq.l #0,d4
+ bsr recv_byte
+ move.b d0,d4
+ bsr recv_byte
+ lsl.l #8,d4
+ move.b d0,d4
+pcc_io_loop:
+ move.b #0x40,(0xa1000b).l /* input mode */
+
+ sub.w #1,d4
+ bmi return
+
+ bsr recv_byte
+ move.b d0,d3 /* cmd */
+
+ bsr recv_ad
+ move.l d0,a2 /* addr */
+
+ cmp.b #IOSEQ_W32, d3
+ beq pcc_io_w32
+ cmp.b #IOSEQ_W16, d3
+ beq pcc_io_w16
+ cmp.b #IOSEQ_W8, d3
+ bne pcc_io_rx
+
+pcc_io_w8:
+ bsr recv_byte
+ move.b d0,(a2)
+ bra pcc_io_loop
+
+pcc_io_w16:
+ bsr recv_byte
+ move.b d0,d3
+ bsr recv_byte
+ lsl.w #8,d3
+ move.b d0,d3
+ move.w d3,(a2)
+ bra pcc_io_loop
+
+pcc_io_w32:
+ bsr recv_byte
+ move.b d0,d3
+ bsr recv_byte
+ lsl.w #8,d3
+ move.b d0,d3
+ bsr recv_byte
+ lsl.l #8,d3
+ move.b d0,d3
+ bsr recv_byte
+ lsl.l #8,d3
+ move.b d0,d3
+ move.l d3,(a2)
+ bra pcc_io_loop
+
+pcc_io_rx:
+ switch_to_output
+
+ cmp.b #IOSEQ_R32, d3
+ beq pcc_io_r32
+ cmp.b #IOSEQ_R16, d3
+ beq pcc_io_r16
+ cmp.b #IOSEQ_R8, d3
+ bne return
+
+pcc_io_r8:
+ move.b (a2),d0
+ bsr send_byte
+ bra pcc_io_loop
+
+pcc_io_r16:
+ move.w (a2),d3
+ move.w d3,d0
+ lsr.w #8,d0
+ bsr send_byte
+ move.b d3,d0
+ bsr send_byte
+ bra pcc_io_loop
+
+pcc_io_r32:
+ move.l (a2),d3
+ move.l d3,d0
+ swap d0
+ lsr.l #8,d0
+ bsr send_byte
+ move.l d3,d0
+ swap d0
+ bsr send_byte
+ move.w d3,d0
+ lsr.w #8,d0
+ bsr send_byte
+ move.b d3,d0
+ bsr send_byte
+ bra pcc_io_loop
+
+
+/* PicoDrive savestate load */
+pcc_loadstate:
+ /* write VRAM */
+ move.l #0xc00000,a0
+ move.w #0x8f02,4(a0) /* auto increment 2 */
+
+ move.l #0x40000000,4(a0)
+ move.l #0x10000/2-1,d3
+tr_do_vram_loop:
+ bsr recv_word
+ move.w d0,(a0)
+ dbra d3, tr_do_vram_loop
+
+ /* write cram */
+ move.l #0xc0000000,4(a0)
+ move.l #0x80/2-1,d3
+tr_do_cram_loop:
+ bsr recv_word
+ move.w d0,(a0)
+ dbra d3, tr_do_cram_loop
+
+ /* write vsram */
+ move.l #0x40000010,4(a0)
+ move.l #0x80/2-1,d3
+tr_do_vsram_loop:
+ bsr recv_word
+ move.w d0,(a0)
+ dbra d3, tr_do_vsram_loop
+
+ /* recv and write regs */
+ lea 0xffe000,a3
+ move.l a3,a2
+ moveq.l #0x20-1,d3
+tr_do_vdpreg_recv_loop:
+ bsr recv_byte
+ move.b d0,(a2)+
+ dbra d3, tr_do_vdpreg_recv_loop
+
+ move.l a3,a2
+ moveq.l #0,d3
+tr_do_vdpreg_loop:
+ move.b d3,d1
+ or.b #0x80,d1
+ lsl.w #8,d1
+ move.b (d3,a2),d1
+ move.w d1,4(a0)
+ addq.l #1,d3
+ cmp.b #0x17,d3 /* FIXME: r23 might cause DMA or.. */
+ bne 0f /* ..something and hang VDP.. */
+ add.b #1,d3 /* ..so we skip it */
+0:
+ cmp.b #0x20,d3
+ blt tr_do_vdpreg_loop
+
+ moveq.l #0,d0
+ move.b 5(a3),d0
+ bsr invalidate_sprite_cache
+
+
+0: bra 0b
+
+ bra return
+
+
+pcc_vram_send:
+ /* write VRAM */
+ move.l #0xc00000,a0
+ move.w #0x8f02,4(a0) /* auto increment 2 */
+ move.l #0,4(a0) /* VRAM read, addr 0 */
+ move.l #0x10000/2-1,d4
+
+ switch_to_output
+
+tr_vram_send_loop:
+ move.w (a0),d3
+ move.w d3,d0
+ lsr.w #8,d0
+ bsr send_byte
+ move.b d3,d0
+ bsr send_byte
+ dbra d4,tr_vram_send_loop
+
+ bra return
+
+
+
+/* some random code */
pcc_test_code:
bra return
+
return:
move.b #0,(0xa1000b).l /* all inputs */
move.l #0xffe000,a1
move.l d2,(a1)+
move.l d3,(a1)+
move.l a0,(a1)+
- bra return_to_main
+ rts
+# bra return_to_main
# vim:filetype=asmM68k
notaz.gp2x.de / megadrive.git / blobdiff