X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=testpico%2Fsega_gcc.s;h=1e0116aeb58dc0e5fd0dca45b4d7be84c0e26da8;hb=HEAD;hp=d4fdc58351adc238146d75d88093608a1ad482e1;hpb=234c45567cc77a4eca9cddca7daaacab27cab767;p=megadrive.git

diff --git a/testpico/sega_gcc.s b/testpico/sega_gcc.s
index d4fdc58..4abb418 100644
--- a/testpico/sega_gcc.s
+++ b/testpico/sega_gcc.s
@@ -16,16 +16,19 @@ exc_tab:
     .ascii "J               "
     .long  0x000000,0x3fffff
     .long  0xff0000,0xffffff
-    .ascii "RA"; .byte 0xf8,0x20                     /* 1b0 */
-    .long  0x200001,0x20ffff                         /* 1b4 */
-    .ascii "    "                                    /* 1bc */
-    .ascii "                        "                /* 1c0 */
-    .ascii "                        "
-    .ascii "JUE             "                        /* 1f0 */
+    .ascii "RA"; .byte 0xf8,0x20                      /* 1b0 */
+    .long  0x200001,0x20ffff                          /* 1b4 */
+    .ascii "    "                                     /* 1bc */
+    .ascii "        "                                 /* 1c0 */
+    .ascii "src: https://github.com/notaz/megadrive/" /* 1c8 */
+    .ascii "JUE             "                         /* 1f0 */
+
+# 32X reset vector (880200)
+    bra     RST32X
 
 # mystery landing area for reset with 32X on and RV=1
 # 2c8 - 304 in multiples of 4
-.rept 0x1c0/2
+.rept 0x1bc/2
     illegal
 .endr
 
@@ -109,20 +112,22 @@ exc_tab:
     .word 0x5100,0x3340,0x0006,0x303C,0x8000,0x6004,0x44FC,0x0001
 
 RST:
-    move.w  #0x2600, %sr
-
-    move.b (0xA10001), %d0
-    andi.b #0x0F, %d0
-    beq.s 0f
-    move.l  #0x53454741, (0xA14000) /* 'SEGA' */
+    andi.b  #0x0F, (0xA10001)       /* 24 */
+    bne.s   0f                      /* 10 */
+    move.w  #0x8104, (0xc00004)
+    bra     1f
 0:
-    tst.w   (0xc00004).l
+    move.l  #0x53454741, (0xA14000) /* 28 'SEGA' */
+1:
+    move.w  (0xc00008), %d0         /* 16 */
+    move.w  %d0, -(%sp)
+    subq.l  #2, %sp
+    move    %sp, %usp
 
-    moveq   #0, %d0
-    movea.l %d0, %a7
-    move    %a7, %usp
+    move.w  #0x2600, %sr
 
     /* clear .bss */
+    moveq.l #0, %d0
     lea     __bss_start, %a0
     lea     __end, %a1
 0:
@@ -139,12 +144,29 @@ RST:
 #VBL:
 #    rte
 
+RST32X:
+    lea     ram_rv_switch, %a0
+    movea.l #0xff0100, %a1
+    lea     ram_rv_switch_end, %a2
+0:
+    move.l  (%a0)+, (%a1)+
+    cmp.l   %a2, %a0
+    blt.s   0b
+    jmp     (0xff0100).l
+
+ram_rv_switch:
+    move.l  (0x880004).l, %a0
+    bset    #0, (0xa15107).l  /* RV=1 */
+    nop                       /* just in case */
+    jmp     (%a0)
+ram_rv_switch_end:
+
 pre_exception:
     move.w  #0x2700, %sr
     movem.l %d0-%d7/%a0-%a7,-(%sp)
-    add.w   #2, 0x3e(%sp)
+    add.w   #2, 0x3e(%sp)   /* ecxnum */
     move.l  %sp, %d0
-    move.l  %d0,-(%sp)  /* arg0 */
+    move.l  %d0,-(%sp)      /* arg0 */
     jsr     exception
 0:
     bra     0b
@@ -152,7 +174,7 @@ pre_exception:
 .macro exc_stub num
 exc\num:
     move.w #0x\num, -(%sp)
-    jmp pre_exception
+    bra pre_exception
 .endm
 
 exc_stub 02