ClassiCube/misc/32x/m68k_crt0.s
2024-09-10 18:00:31 +10:00

99 lines
4.3 KiB
ArmAsm

| SEGA 32X support code for the 68000
| by Chilly Willy
| First part of rom header
.text
| Initial exception vectors. When the console is first turned on, it is
| in MegaDrive mode. All vectors just point to the code to start up the
| Mars adapter. After the adapter is enabled, none of these vectors will
| appear as the adapter uses its own vector table to route exceptions to
| the jump table. 0x3F0 is where the 68000 starts at for the 32X.
.long 0x01000000,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
.long 0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0,0x000003F0
| Standard MegaDrive ROM header at 0x100
.ascii "SEGA 32X Example" /* SEGA must be the first four chars for TMSS */
.ascii "(C)2024 "
.ascii "ClassiCube 32X " /* export name */
.ascii " "
.ascii " "
.ascii "ClassiCube 32X " /* domestic (Japanese) name */
.ascii " "
.ascii " "
.ascii "GM MK-0000 -00"
.word 0x0000 /* checksum - not needed */
.ascii "J6 "
.long 0x00000000,0x0007FFFF /* ROM start, end */
.long 0x00FF0000,0x00FFFFFF /* RAM start, end */
.ifdef HAS_SAVE_RAM
.ascii "RA" /* External RAM */
.byte 0xF8 /* don't clear + odd bytes */
.byte 0x20 /* SRAM */
.long 0x00200001,0x0020FFFF /* SRAM start, end */
.else
.ascii " " /* no SRAM */
.endif
.ascii " "
.ascii " "
.ifdef MYTH_HOMEBREW
.ascii "MYTH3900" /* memo indicates Myth native executable */
.else
.ascii " " /* memo */
.endif
.ascii " "
.ascii " "
.ascii "F " /* enable any hardware configuration */
| Mars exception vector jump table at 0x200
jmp 0x880800.l /* reset = hot start */
jsr 0x880806.l /* EX_BusError */
jsr 0x880806.l /* EX_AddrError */
jsr 0x880806.l /* EX_IllInstr */
jsr 0x880806.l /* EX_DivByZero */
jsr 0x880806.l /* EX_CHK */
jsr 0x880806.l /* EX_TrapV */
jsr 0x880806.l /* EX_Priviledge */
jsr 0x880806.l /* EX_Trace */
jsr 0x880806.l /* EX_LineA */
jsr 0x880806.l /* EX_LineF */
.space 72 /* reserved */
jsr 0x880806.l /* EX_Spurious */
jsr 0x880806.l /* EX_Level1 */
jsr 0x880806.l /* EX_Level2 */
jsr 0x880806.l /* EX_Level3 */
jmp 0x88080C.l /* EX_Level4 HBlank */
jsr 0x880806.l /* EX_Level5 */
jmp 0x880812.l /* EX_Level6 VBlank */
jsr 0x880806.l /* EX_Level7 */
jsr 0x880806.l /* EX_Trap0 */
jsr 0x880806.l /* EX_Trap1 */
jsr 0x880806.l /* EX_Trap2 */
jsr 0x880806.l /* EX_Trap3 */
jsr 0x880806.l /* EX_Trap4 */
jsr 0x880806.l /* EX_Trap5 */
jsr 0x880806.l /* EX_Trap6 */
jsr 0x880806.l /* EX_Trap7 */
jsr 0x880806.l /* EX_Trap8 */
jsr 0x880806.l /* EX_Trap9 */
jsr 0x880806.l /* EX_TrapA */
jsr 0x880806.l /* EX_TrapB */
jsr 0x880806.l /* EX_TrapC */
jsr 0x880806.l /* EX_TrapD */
jsr 0x880806.l /* EX_TrapE */
jsr 0x880806.l /* EX_TrapF */
.space 166 /* reserved */