// dc_hw.c - Hardware found on the ARM7/AICA side of the Dreamcast #include "ao.h" #include "dc_hw.h" #include "aica.h" #define DK_CORE (1) #if DK_CORE #include "arm7.h" #else #include "arm7core.h" #endif uint8 dc_ram[8*1024*1024]; static void aica_irq(int irq) { if (irq > 0) { #if DK_CORE ARM7_SetFIQ(TRUE); #else set_irq_line(ARM7_FIRQ_LINE, 1); #endif } else { #if DK_CORE ARM7_SetFIQ(FALSE); #else set_irq_line(ARM7_FIRQ_LINE, 0); #endif } } #define MIXER_PAN_LEFT 1 #define MIXER_PAN_RIGHT 2 #define MIXER(level,pan) ((level & 0xff) | ((pan & 0x03) << 8)) #define YM3012_VOL(LVol,LPan,RVol,RPan) (MIXER(LVol,LPan)|(MIXER(RVol,RPan) << 16)) static struct AICAinterface aica_interface = { 1, { dc_ram, }, { YM3012_VOL(100, MIXER_PAN_LEFT, 100, MIXER_PAN_RIGHT) }, { aica_irq, }, }; uint8 dc_read8(int addr) { if (addr < 0x800000) { return dc_ram[addr]; } if ((addr >= 0x800000) && (addr <= 0x807fff)) { int foo = AICA_0_r((addr-0x800000)/2, 0); if (addr & 1) { return foo>>8; } else { return foo & 0xff; } } printf("R8 @ %x\n", addr); return -1; } uint16 dc_read16(int addr) { if (addr < 0x800000) { return dc_ram[addr] | (dc_ram[addr+1]<<8); } if ((addr >= 0x800000) && (addr <= 0x807fff)) { return AICA_0_r((addr-0x800000)/2, 0); } printf("R16 @ %x\n", addr); return -1; } uint32 dc_read32(int addr) { if (addr < 0x800000) { return dc_ram[addr] | (dc_ram[addr+1]<<8) | (dc_ram[addr+2]<<16) | (dc_ram[addr+3]<<24); } if ((addr >= 0x800000) && (addr <= 0x807fff)) { addr &= 0x7fff; return AICA_0_r(addr/2, 0) & 0xffff; } // printf("R32 @ %x\n", addr); return 0; } void dc_write8(int addr, uint8 data) { if (addr < 0x800000) { dc_ram[addr] = data; return; } if ((addr >= 0x800000) && (addr <= 0x807fff)) { addr -= 0x800000; if ((addr & 1)) AICA_0_w(addr>>1, data<<8, 0x00ff); else AICA_0_w(addr>>1, data, 0xff00); return; } printf("W8 %x @ %x\n", data, addr); } void dc_write16(int addr, uint16 data) { if (addr < 0x800000) { dc_ram[addr] = data&0xff; dc_ram[addr+1] = (data>>8) & 0xff; return; } if ((addr >= 0x800000) && (addr <= 0x807fff)) { AICA_0_w((addr-0x800000)/2, data, 0); return; } printf("W16 %x @ %x\n", data, addr); } void dc_write32(int addr, uint32 data) { if (addr < 0x800000) { dc_ram[addr] = data&0xff; dc_ram[addr+1] = (data>>8) & 0xff; dc_ram[addr+2] = (data>>16) & 0xff; dc_ram[addr+3] = (data>>24) & 0xff; return; } if ((addr >= 0x800000) && (addr <= 0x807fff)) { addr -= 0x800000; AICA_0_w((addr>>1), data&0xffff, 0x0000); AICA_0_w((addr>>1)+1, data>>16, 0x0000); return; } printf("W32 %x @ %x\n", data, addr); } void dc_hw_init(void) { aica_interface.region[0] = dc_ram; aica_start(&aica_interface); }