megadrive_test1

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copied the bgset code from samurai's article to test that my dev setup is actually working
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 30 Jan 2017 16:57:51 +0200
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1 | the following will go into the custom .romhdr section which will be placed at
2 | address 100 of the binary by the linker (see lnkscript).
3 .section .romhdr,"a"
4
5 #ifndef GAMENAME
6 #define GAMENAME "unnamed"
7 #endif
8 #ifndef VERSTR
9 #define VERSTR "00"
10 #endif
11
12 .ascii "SEGA MEGA DRIVE (C)MINDLAPSE2017"
13 hdr_game_dom:
14 .ascii GAMENAME
15 hdr_game_dom_end:
16 .fill 48 - (hdr_game_dom_end - hdr_game_dom),1,32 | pad to 48 bytes with spaces
17 hdr_game_int:
18 .ascii GAMENAME
19 hdr_game_int_end:
20 .fill 48 - (hdr_game_int_end - hdr_game_int),1,32 | pad to 48 bytes with spaces
21 .ascii "GM" | it's a game (who cares what it is?)
22 .ascii "0000000-" | product code
23 .ascii VERSTR | version string
24 .short 0 | checksum
25 .ascii "J " | I/O support (joypad)
26 .long 0 | start address of ROM
27 .long _rom_end | last address of ROM
28 .long 0xff0000 | start address of RAM
29 .long 0xffffff | last address of RAM
30 .long 0 | SRAM enabled(?)
31 .long 0 | ???
32 .long 0 | start address of SRAM
33 .long 0 | last address of SRAM
34 .long 0 | ???
35 .long 0 | ???
36 .fill 40,1,32 | notes (fill with spaces for now TODO)
37 .ascii "JUE " | country codes