clear vram/cram/vsram on init

diff --git a/src/vdp.S b/src/vdp.S
index 1d62565..5727a56 100644 (file)
--- a/src/vdp.S
+++ b/src/vdp.S
@@ -1,12 +1,12 @@
        .text
 
+#define ASM
 #include "hwregs.h"
 
        .globl vdp_init
 vdp_init:
-       | initialize registers
-       move.l #def_reg_tab, %a0
-       clr.w %d1
+       movea.l #def_reg_tab, %a0
+       move.w #0, %d1
 0:     move.w %d1, %d0
        lsl.w #8, %d0
        or.w #0x8000, %d0
@@ -16,17 +16,32 @@ vdp_init:
        cmp.w def_reg_tab_size, %d1
        bne.s 0b
 
-       | clear VRAM
-       clr.l %d0
+       | clear vram
+       movea.l #VDP_DATA_PORT, %a0
+       moveq #0, %d0
        move.l #VDP_VRAM, %d1
        bsr setup_addr
-       clr.w %d0
-       move.w #0xffff, %d1
-0:     move.w %d0, VDP_DATA_PORT
-       dbra.w %d1, 0b
-       
-       rts
+       moveq #0, %d0
+       move.l #0x7fff, %d1     | 64k / 2 - 1
+0:     move.w %d0, (%a0)
+       dbra %d1, 0b
 
+       | clear colormaps
+       move.l #VDP_CRAM, %d1
+       bsr setup_addr
+       moveq #0, %d0
+       move.l #63, %d1         | 4 palettes * 16 col * 2 bytes / 2 - 1
+0:     move.w %d0, (%a0)
+       dbra %d1, 0b
+
+       | clear vscroll
+       move.l #VDP_VSRAM, %d1
+       bsr setup_addr
+       moveq #0, %d0
+       move.l #39, %d1         | 80 bytes / 2 - 1
+0:     move.w %d0, (%a0)
+       dbra %d1, 0b
+       rts
 
        | address in d0, type in d1
 setup_addr:
@@ -40,9 +55,8 @@ setup_addr:
        .globl vdp_setcolor
 vdp_setcolor:
        move.l 4(%sp), %d0      | palette number
-       lsl.l #4, %d0
+       lsl.l #5, %d0
        add.l 8(%sp), %d0       | add index
-       lsl.l #1, %d0
        move.l #VDP_CRAM, %d1
        bsr setup_addr
        move.w 22(%sp), %d0     | blue
@@ -54,12 +68,12 @@ vdp_setcolor:
        move.w %d0, VDP_DATA_PORT
        rts
 
-       .section .rodata
+       .data
 def_reg_tab:
        .byte VDP_M1_INIT                       | 0: mode 1
        .byte VDP_M2_INIT + VDP_M2_DISP         | 1: mode 2
        .byte VDP_NA_ADDR(0xc000)               | 2: scroll A nametable addr.
-       .byte VDP_NW_ADDR(VDP_ADDR_INVAL)       | 3: window nametable addr.
+       .byte 0                                 | 3: window nametable addr.
        .byte VDP_NB_ADDR(0xd000)               | 4: scroll B nametable addr.
        .byte VDP_SPRTAB_ADDR(0xe000)           | 5: sprite table addr.
        .byte 0
@@ -68,7 +82,7 @@ def_reg_tab:
        .byte 0                                 | 10: horiz. interrupt interval
        .byte 0                                 | 11: mode 3
        .byte VDP_M4_H40                        | 12: mode 4
-       .byte 0                                 | 13: hscroll table addr.
+       .byte VDP_HSTAB_ADDR(0xf000)            | 13: hscroll table addr.
        .byte 0
        .byte 2                                 | 15: autoincrement 2 bytes
        .byte VDP_SCR_H64                       | 16: scroll size (64x32)