commit 34ae22b6a56e37d6c7c33c33146eb7556255267c Author: DIvan2000 Date: Mon Sep 22 18:58:42 2025 +0400 initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..89f9ac0 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +out/ diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..3ee6bc4 --- /dev/null +++ b/Makefile @@ -0,0 +1,11 @@ +GDK ?= /opt/SGDK +SRC = src +OUT = out + +all: + $(MAKE) -f $(GDK)/makefile_wine.gen GDK=$(GDK) WINE=wine \ + SRC=$(SRC) OUT=$(OUT) + +clean: + $(MAKE) -f $(GDK)/makefile_wine.gen clean GDK=$(GDK) WINE=wine \ + SRC=$(SRC) OUT=$(OUT) diff --git a/README.md b/README.md new file mode 100644 index 0000000..e69de29 diff --git a/src/boot/rom_head.c b/src/boot/rom_head.c new file mode 100644 index 0000000..50f0b0b --- /dev/null +++ b/src/boot/rom_head.c @@ -0,0 +1,33 @@ +#include "genesis.h" + +__attribute__((externally_visible)) +const ROMHeader rom_header = { +#if (ENABLE_BANK_SWITCH != 0) + "SEGA SSF ", +#elif (MODULE_MEGAWIFI != 0) + "SEGA MEGAWIFI ", +#else + "SEGA MEGA DRIVE ", +#endif + "(C)SGDK 2024 ", + "SAMPLE PROGRAM ", + "SAMPLE PROGRAM ", + "GM 00000000-00", + 0x000, + "JD ", + 0x00000000, +#if (ENABLE_BANK_SWITCH != 0) + 0x003FFFFF, +#else + 0x000FFFFF, +#endif + 0xE0FF0000, + 0xE0FFFFFF, + "RA", + 0xF820, + 0x00200000, + 0x0020FFFF, + " ", + "DEMONSTRATION PROGRAM ", + "JUE " +}; diff --git a/src/boot/sega.s b/src/boot/sega.s new file mode 100644 index 0000000..097c35a --- /dev/null +++ b/src/boot/sega.s @@ -0,0 +1,367 @@ +#include "task_cst.h" + +.section .text.keepboot + +*------------------------------------------------------- +* +* Sega startup code for the GNU Assembler +* Translated from: +* Sega startup code for the Sozobon C compiler +* Written by Paul W. Lee +* Modified by Charles Coty +* Modified by Stephane Dallongeville +* +*------------------------------------------------------- + + .globl rom_header + + .org 0x00000000 + +_Start_Of_Rom: +_Vecteurs_68K: + dc.l __stack /* Stack address */ + dc.l _Entry_Point /* Program start address */ + dc.l _Bus_Error + dc.l _Address_Error + dc.l _Illegal_Instruction + dc.l _Zero_Divide + dc.l _Chk_Instruction + dc.l _Trapv_Instruction + dc.l _Privilege_Violation + dc.l _Trace + dc.l _Line_1010_Emulation + dc.l _Line_1111_Emulation + dc.l _Error_Exception, _Error_Exception, _Error_Exception, _Error_Exception + dc.l _Error_Exception, _Error_Exception, _Error_Exception, _Error_Exception + dc.l _Error_Exception, _Error_Exception, _Error_Exception, _Error_Exception + dc.l _Error_Exception + dc.l _INT + dc.l _EXTINT + dc.l _INT + dc.l hintCaller + dc.l _INT + dc.l _VINT + dc.l _INT + dc.l _trap_0 /* Resume supervisor task */ + dc.l _INT,_INT,_INT,_INT,_INT,_INT,_INT + dc.l _INT,_INT,_INT,_INT,_INT,_INT,_INT,_INT + dc.l _INT,_INT,_INT,_INT,_INT,_INT,_INT,_INT + dc.l _INT,_INT,_INT,_INT,_INT,_INT,_INT,_INT + +rom_header: + .incbin "out/rom_head.bin", 0, 0x100 + +_Entry_Point: +* disable interrupts + move #0x2700,%sr + +* Configure a USER_STACK_LENGTH bytes user stack at bottom, and system stack on top of it + move %sp, %usp + sub #USER_STACK_LENGTH, %sp + +* Halt Z80 (need to be done as soon as possible on reset) + move.l #0xA11100,%a0 /* Z80_HALT_PORT */ + move.w #0x0100,%d0 + move.w %d0,(%a0) /* HALT Z80 */ + move.w %d0,0x0100(%a0) /* END RESET Z80 */ + + tst.l 0xa10008 + bne.s SkipInit + + tst.w 0xa1000c + bne.s SkipInit + +* Check Version Number + move.b -0x10ff(%a0),%d0 + andi.b #0x0f,%d0 + beq.s NoTMSS + +* Sega Security Code (SEGA) + move.l #0x53454741,0x2f00(%a0) + +NoTMSS: + jmp _start_entry + +SkipInit: + jmp _reset_entry + + +*------------------------------------------------ +* +* interrupt functions +* +*------------------------------------------------ + +_INT: + movem.l %d0-%d1/%a0-%a1,-(%sp) + move.l intCB, %a0 + jsr (%a0) + movem.l (%sp)+,%d0-%d1/%a0-%a1 + rte + +_EXTINT: + movem.l %d0-%d1/%a0-%a1,-(%sp) + move.l eintCB, %a0 + jsr (%a0) + movem.l (%sp)+,%d0-%d1/%a0-%a1 + rte + +_VINT: + btst #5, (%sp) /* Skip context switch if not in user task */ + bne.s no_user_task + + tst.w task_lock + bne.s 1f + move.w #0, -(%sp) /* TSK_superPend() will return 0 */ + bra.s unlock /* If lock == 0, supervisor task is not locked */ + +1: + bcs.s no_user_task /* If lock < 0, super is locked with infinite wait */ + subq.w #1, task_lock /* Locked with wait, subtract 1 to the frame count */ + bne.s no_user_task /* And do not unlock if we did not reach 0 */ + move.w #1, -(%sp) /* TSK_superPend() will return 1 */ + +unlock: + /* Save bg task registers (excepting a7, that is stored in usp) */ + move.l %a0, task_regs + lea (task_regs + UTSK_REGS_LEN), %a0 + movem.l %d0-%d7/%a1-%a6, -(%a0) + + move.w (%sp)+, %d0 /* Load return value previously pushed to stack */ + + move.w (%sp)+, task_sr /* Pop user task sr and pc, and save them, */ + move.l (%sp)+, task_pc /* so they can be restored later. */ + movem.l (%sp)+, %d2-%d7/%a2-%a6 /* Restore non clobberable registers */ + +no_user_task: + /* At this point, we always have in the stack the SR and PC of the task */ + /* we want to jump after processing the interrupt, that might be the */ + /* point where we came from (if there is no context switch) or the */ + /* supervisor task (if we unlocked it). */ + + movem.l %d0-%d1/%a0-%a1,-(%sp) + ori.w #0x0001, intTrace /* in V-Int */ + addq.l #1, vtimer /* increment frame counter (more a vint counter) */ + btst #3, VBlankProcess+1 /* PROCESS_XGM_TASK ? (use VBlankProcess+1 as btst is a byte operation) */ + beq.s no_xgm_task + + jsr XGM_doVBlankProcess /* do XGM vblank task */ + +no_xgm_task: + btst #1, VBlankProcess+1 /* PROCESS_BITMAP_TASK ? (use VBlankProcess+1 as btst is a byte operation) */ + beq.s no_bmp_task + + jsr BMP_doVBlankProcess /* do BMP vblank task */ + +no_bmp_task: + move.l vintCB, %a0 /* load user callback */ + jsr (%a0) /* call user callback */ + andi.w #0xFFFE, intTrace /* out V-Int */ + movem.l (%sp)+,%d0-%d1/%a0-%a1 + rte + +*------------------------------------------------ +* +* Copyright (c) 1988 by Sozobon, Limited. Author: Johann Ruegg +* +* Permission is granted to anyone to use this software for any purpose +* on any computer system, and to redistribute it freely, with the +* following restrictions: +* 1) No charge may be made other than reasonable charges for reproduction. +* 2) Modified versions must be clearly marked as such. +* 3) The authors are not responsible for any harmful consequences +* of using this software, even if they result from defects in it. +* +*------------------------------------------------ + +ldiv: + move.l 4(%a7),%d0 + bpl ld1 + neg.l %d0 +ld1: + move.l 8(%a7),%d1 + bpl ld2 + neg.l %d1 + eor.b #0x80,4(%a7) +ld2: + bsr i_ldiv /* d0 = d0/d1 */ + tst.b 4(%a7) + bpl ld3 + neg.l %d0 +ld3: + rts + +lmul: + move.l 4(%a7),%d0 + bpl lm1 + neg.l %d0 +lm1: + move.l 8(%a7),%d1 + bpl lm2 + neg.l %d1 + eor.b #0x80,4(%a7) +lm2: + bsr i_lmul /* d0 = d0*d1 */ + tst.b 4(%a7) + bpl lm3 + neg.l %d0 +lm3: + rts + +lrem: + move.l 4(%a7),%d0 + bpl lr1 + neg.l %d0 +lr1: + move.l 8(%a7),%d1 + bpl lr2 + neg.l %d1 +lr2: + bsr i_ldiv /* d1 = d0%d1 */ + move.l %d1,%d0 + tst.b 4(%a7) + bpl lr3 + neg.l %d0 +lr3: + rts + +ldivu: + move.l 4(%a7),%d0 + move.l 8(%a7),%d1 + bsr i_ldiv + rts + +lmulu: + move.l 4(%a7),%d0 + move.l 8(%a7),%d1 + bsr i_lmul + rts + +lremu: + move.l 4(%a7),%d0 + move.l 8(%a7),%d1 + bsr i_ldiv + move.l %d1,%d0 + rts +* +* A in d0, B in d1, return A*B in d0 +* +i_lmul: + move.l %d3,%a2 /* save d3 */ + move.w %d1,%d2 + mulu %d0,%d2 /* d2 = Al * Bl */ + + move.l %d1,%d3 + swap %d3 + mulu %d0,%d3 /* d3 = Al * Bh */ + + swap %d0 + mulu %d1,%d0 /* d0 = Ah * Bl */ + + add.l %d3,%d0 /* d0 = (Ah*Bl + Al*Bh) */ + swap %d0 + clr.w %d0 /* d0 = (Ah*Bl + Al*Bh) << 16 */ + + add.l %d2,%d0 /* d0 = A*B */ + move.l %a2,%d3 /* restore d3 */ + rts +* +*A in d0, B in d1, return A/B in d0, A%B in d1 +* +i_ldiv: + tst.l %d1 + bne nz1 + +* divide by zero +* divu #0,%d0 /* cause trap */ + move.l #0x80000000,%d0 + move.l %d0,%d1 + rts +nz1: + move.l %d3,%a2 /* save d3 */ + cmp.l %d1,%d0 + bhi norm + beq is1 +* AB and B is not 0 +norm: + cmp.l #1,%d1 + bne not1 +* B==1, so ret A, rem 0 + clr.l %d1 + move.l %a2,%d3 /* restore d3 */ + rts +* check for A short (implies B short also) +not1: + cmp.l #0xffff,%d0 + bhi slow +* A short and B short -- use 'divu' + divu %d1,%d0 /* d0 = REM:ANS */ + swap %d0 /* d0 = ANS:REM */ + clr.l %d1 + move.w %d0,%d1 /* d1 = REM */ + clr.w %d0 + swap %d0 + move.l %a2,%d3 /* restore d3 */ + rts +* check for B short +slow: + cmp.l #0xffff,%d1 + bhi slower +* A long and B short -- use special stuff from gnu + move.l %d0,%d2 + clr.w %d2 + swap %d2 + divu %d1,%d2 /* d2 = REM:ANS of Ahi/B */ + clr.l %d3 + move.w %d2,%d3 /* d3 = Ahi/B */ + swap %d3 + + move.w %d0,%d2 /* d2 = REM << 16 + Alo */ + divu %d1,%d2 /* d2 = REM:ANS of stuff/B */ + + move.l %d2,%d1 + clr.w %d1 + swap %d1 /* d1 = REM */ + + clr.l %d0 + move.w %d2,%d0 + add.l %d3,%d0 /* d0 = ANS */ + move.l %a2,%d3 /* restore d3 */ + rts +* A>B, B > 1 +slower: + move.l #1,%d2 + clr.l %d3 +moreadj: + cmp.l %d0,%d1 + bhs adj + add.l %d2,%d2 + add.l %d1,%d1 + bpl moreadj +* we shifted B until its >A or sign bit set +* we shifted #1 (d2) along with it +adj: + cmp.l %d0,%d1 + bhi ltuns + or.l %d2,%d3 + sub.l %d1,%d0 +ltuns: + lsr.l #1,%d1 + lsr.l #1,%d2 + bne adj +* d3=answer, d0=rem + move.l %d0,%d1 + move.l %d3,%d0 + move.l %a2,%d3 /* restore d3 */ + rts diff --git a/src/gfx/pointer.png b/src/gfx/pointer.png new file mode 100644 index 0000000..5f46f22 Binary files /dev/null and b/src/gfx/pointer.png differ diff --git a/src/main.c b/src/main.c new file mode 100644 index 0000000..5d9423d --- /dev/null +++ b/src/main.c @@ -0,0 +1,68 @@ +#include "genesis.h" + +#define MOUSE_PORT ((volatile u8*)0xA10003) +#define Z80_HALT *((volatile u16*)0xA11100) + +#define MOUSE_DELAY 32 + +static inline void delay() { + for(int i=0;i