From: notaz Date: Tue, 7 Apr 2009 22:43:19 +0000 (+0000) Subject: cleanup init code X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?p=megadrive.git;a=commitdiff_plain;h=4fce116e2906a6913d394c106721e701e11c1781 cleanup init code --- diff --git a/hexed/sega_gcc.s b/hexed/sega_gcc.s index 441d74c..99ecd31 100644 --- a/hexed/sega_gcc.s +++ b/hexed/sega_gcc.s @@ -1,13 +1,3 @@ -*------------------------------------------------------- -* -* Sega startup code for the GNU Assembler -* Translated from: -* Sega startup code for the Sozobon C compiler -* Written by Paul W. Lee -* Modified from Charles Coty's code -* -*------------------------------------------------------- - dc.l 0x0,0x200 dc.l INT,INT,INT,INT,INT,INT,INT dc.l INT,INT,INT,INT,INT,INT,INT,INT @@ -29,174 +19,30 @@ .ascii " " .ascii " " .ascii "JUE " -*debugee: -* bra debugee - tst.l 0xa10008 - bne SkipJoyDetect - tst.w 0xa1000c -SkipJoyDetect: + + tst.l 0xa10008 bne SkipSetup - lea Table,%a5 - movem.w (%a5)+,%d5-%d7 - movem.l (%a5)+,%a0-%a4 -* Check Version Number - move.b -0x10ff(%a1),%d0 - andi.b #0x0f,%d0 - beq WrongVersion -* Sega Security Code (SEGA) - move.l #0x53454741,0x2f00(%a1) +* Check Version Number + move.b (0xa10000),%d0 + andi.b #0x0f,%d0 + beq WrongVersion +* Sega Security Code (SEGA) + move.l #0x53454741,(0xa14000) WrongVersion: - move.w (%a4),%d0 - moveq #0x00,%d0 - movea.l %d0,%a6 - move %a6,%usp -* Set VDP registers - moveq #0x17,%d1 -FillLoop: - move.b (%a5)+,%d5 - move.w %d5,(%a4) - add.w %d7,%d5 - dbra %d1,FillLoop - move.l (%a5)+,(%a4) - move.w %d0,(%a3) - move.w %d7,(%a1) - move.w %d7,(%a2) -L0250: - btst %d0,(%a1) - bne L0250 -* Put initial values into a00000 - moveq #0x25,%d2 -Filla: - move.b (%a5)+,(%a0)+ - dbra %d2,Filla - move.w %d0,(%a2) - move.w %d0,(%a1) - move.w %d7,(%a2) -L0262: - move.l %d0,-(%a6) - dbra %d6,L0262 - move.l (%a5)+,(%a4) - move.l (%a5)+,(%a4) -* Put initial values into c00000 - moveq #0x1f,%d3 -Filc0: - move.l %d0,(%a3) - dbra %d3,Filc0 - move.l (%a5)+,(%a4) -* Put initial values into c00000 - moveq #0x13,%d4 -Fillc1: - move.l %d0,(%a3) - dbra %d4,Fillc1 -* Put initial values into c00011 - moveq #0x03,%d5 -Fillc2: - move.b (%a5)+,0x0011(%a3) - dbra %d5,Fillc2 - move.w %d0,(%a2) - movem.l (%a6),%d0-%d7/%a0-%a6 - move #0x2700,%sr + moveq #0,%d0 + movea.l %d0,%a7 + move %a7,%usp SkipSetup: - bra Continue -Table: - dc.w 0x8000, 0x3fff, 0x0100, 0x00a0, 0x0000, 0x00a1, 0x1100, 0x00a1 - dc.w 0x1200, 0x00c0, 0x0000, 0x00c0, 0x0004, 0x0414, 0x302c, 0x0754 - dc.w 0x0000, 0x0000, 0x0000, 0x812b, 0x0001, 0x0100, 0x00ff, 0xff00 - dc.w 0x0080, 0x4000, 0x0080, 0xaf01, 0xd91f, 0x1127, 0x0021, 0x2600 - dc.w 0xf977, 0xedb0, 0xdde1, 0xfde1, 0xed47, 0xed4f, 0xd1e1, 0xf108 - dc.w 0xd9c1, 0xd1e1, 0xf1f9, 0xf3ed, 0x5636, 0xe9e9, 0x8104, 0x8f01 - dc.w 0xc000, 0x0000, 0x4000, 0x0010, 0x9fbf, 0xdfff - -Continue: - tst.w 0x00C00004 - -* set stack pointer -* clr.l %a7 - move.w #0,%a7 - -* user mode - move.w #0x2300,%sr - -* clear Genesis RAM - lea 0xff0000,%a0 - moveq #0,%d0 -clrram: move.w #0,(%a0)+ - subq.w #2,%d0 - bne clrram - -*---------------------------------------------------------- -* -* Load driver into the Z80 memory -* -*---------------------------------------------------------- - -* halt the Z80 - move.w #0x100,0xa11100 -* reset it - move.w #0x100,0xa11200 + tst.w 0xC00004 + jmp main - lea Z80Driver,%a0 - lea 0xa00000,%a1 - move.l #Z80DriverEnd,%d0 - move.l #Z80Driver,%d1 - sub.l %d1,%d0 -Z80loop: - move.b (%a0)+,(%a1)+ - subq.w #1,%d0 - bne Z80loop - -* enable the Z80 - move.w #0x0,0xa11100 - -*---------------------------------------------------------- - jmp main - -INT: - rte +* INT: +* rte HBL: - /* addq.l #1,htimer */ rte * VBL: * addq.l #1,(vtimer).l * rte -*---------------------------------------------------------- -* -* Z80 Sound Driver -* -*---------------------------------------------------------- -Z80Driver: - dc.b 0xc3,0x46,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 - dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0xf3,0xed - dc.b 0x56,0x31,0x00,0x20,0x3a,0x39,0x00,0xb7 - dc.b 0xca,0x4c,0x00,0x21,0x3a,0x00,0x11,0x40 - dc.b 0x00,0x01,0x06,0x00,0xed,0xb0,0x3e,0x00 - dc.b 0x32,0x39,0x00,0x3e,0xb4,0x32,0x02,0x40 - dc.b 0x3e,0xc0,0x32,0x03,0x40,0x3e,0x2b,0x32 - dc.b 0x00,0x40,0x3e,0x80,0x32,0x01,0x40,0x3a - dc.b 0x43,0x00,0x4f,0x3a,0x44,0x00,0x47,0x3e - dc.b 0x06,0x3d,0xc2,0x81,0x00,0x21,0x00,0x60 - dc.b 0x3a,0x41,0x00,0x07,0x77,0x3a,0x42,0x00 - dc.b 0x77,0x0f,0x77,0x0f,0x77,0x0f,0x77,0x0f - dc.b 0x77,0x0f,0x77,0x0f,0x77,0x0f,0x77,0x3a - dc.b 0x40,0x00,0x6f,0x3a,0x41,0x00,0xf6,0x80 - dc.b 0x67,0x3e,0x2a,0x32,0x00,0x40,0x7e,0x32 - dc.b 0x01,0x40,0x21,0x40,0x00,0x7e,0xc6,0x01 - dc.b 0x77,0x23,0x7e,0xce,0x00,0x77,0x23,0x7e - dc.b 0xce,0x00,0x77,0x3a,0x39,0x00,0xb7,0xc2 - dc.b 0x4c,0x00,0x0b,0x78,0xb1,0xc2,0x7f,0x00 - dc.b 0x3a,0x45,0x00,0xb7,0xca,0x4c,0x00,0x3d - dc.b 0x3a,0x45,0x00,0x06,0xff,0x0e,0xff,0xc3 - dc.b 0x7f,0x00 -Z80DriverEnd: - -