SpritesMind.Net

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; The RAM-resident Game Raccoon executable image is installed
; at the front of RAM.
RACCOON_RAM_RESIDENT_DESTINATION = RAM_START

        org $200
; We're going to put the binaries blob at $200 so we can calculate all the offsets
; and lengths in advance. 'main' will be pushed down into the ROM by the binaries
; archive, but that is of no consequence since the Mega Drive cart header is
; generated from the 'main' symbol.

        incbin  "included_binaries.bin"

        align   2
; Entry point when cart is booted.
main:
        ; Initialise Mega Drive:
        ; We want to satisfy the TMSS check as soon as possible.
        interrupts_disable
        move.b  (MM_VERSION_REGISTER+1),d0       ; Load the low byte from the version register.
        and.b   #$0F,d0
        beq     tmss_satisfy_tmss_unnecessary
        move.l  #"SEGA",(MM_TMSS_REGISTER)       ; Satisy TMSS on version != zero consoles by writing SEGA longword to its register.
tmss_satisfy_tmss_unnecessary:                   ; Branch here if we're on a version zero console that does not require TMSS compliance.
        
        ; Past this point, the console is entirely at our command.
        ; I'm going to copy the Game Raccoon Executable Area
        ; into RAM $FF0000...
        lea     raccoon_ram_resident_rom_included_block_start,a0
        lea     RACCOON_RAM_RESIDENT_DESTINATION,a1
        move.w  #(RACCOON_RAM_RESIDENT_ROM_INCLUDED_BLOCK_LENGTH_LONGS-1),d0
copy_next_long:        
        move.l  (a0)+,(a1)+
        dbf     d0,copy_next_long

        jmp     RACCOON_RAM_RESIDENT_DESTINATION
        
        ; Include the RAM-resident portion of the code contiguous in ROM,
        ; but with instructions based at the corresponding position in RAM.
        align   2        

raccoon_ram_resident_rom_included_block_start:        
        ; This file must always be a multiple of 4 large.
        ; (All the variables it messes with expect to begin on a long aligned address in RAM.)
        ; I want to ensure that in the assembly of raccoonramresident.68k.asm.
        incbin  "raccoonramresident.bin"
raccoon_ram_resident_rom_included_block_end = *

RACCOON_RAM_RESIDENT_ROM_INCLUDED_BLOCK_LENGTH_BYTES = raccoon_ram_resident_rom_included_block_end-raccoon_ram_resident_rom_included_block_start
RACCOON_RAM_RESIDENT_ROM_INCLUDED_BLOCK_LENGTH_LONGS = (RACCOON_RAM_RESIDENT_ROM_INCLUDED_BLOCK_LENGTH_BYTES/4)

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void sd_op_delay() __attribute__ ((section (".data")));
void sd_op_delay()
{
    short i;

    for (i=0; i<16; i++)
    {
        asm("nop\n");
    }
}