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gpsp/main.c

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/* gameplaySP
*
* Copyright (C) 2006 Exophase <exophase@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "common.h"
#include <ctype.h>
timer_type timer[4];
const u32 global_cycles_per_instruction = 1;
u32 cpu_ticks = 0;
u32 execute_cycles = 960;
s32 video_count = 960;
u32 last_frame = 0;
u32 flush_ram_count = 0;
u32 gbc_update_count = 0;
u32 oam_update_count = 0;
char main_path[512];
char save_path[512];
void trigger_ext_event(void);
static unsigned update_timers(irq_type *irq_raised, unsigned completed_cycles)
{
unsigned i, ret = 0;
for (i = 0; i < 4; i++)
{
if(timer[i].status == TIMER_INACTIVE)
continue;
if(timer[i].status != TIMER_CASCADE)
{
timer[i].count -= completed_cycles;
/* io_registers accessors range: REG_TM0D, REG_TM1D, REG_TM2D, REG_TM3D */
write_ioreg(REG_TM0D + (i * 2), -(timer[i].count > timer[i].prescale));
}
if(timer[i].count > 0)
continue;
/* irq_raised value range: IRQ_TIMER0, IRQ_TIMER1, IRQ_TIMER2, IRQ_TIMER3 */
if(timer[i].irq)
*irq_raised |= (8 << i);
if((i != 3) && (timer[i + 1].status == TIMER_CASCADE))
{
timer[i + 1].count--;
write_ioreg(REG_TM0D + (i + 1) * 2, -timer[i+1].count);
}
if(i < 2)
{
if(timer[i].direct_sound_channels & 0x01)
ret += sound_timer(timer[i].frequency_step, 0);
if(timer[i].direct_sound_channels & 0x02)
ret += sound_timer(timer[i].frequency_step, 1);
}
timer[i].count += (timer[i].reload << timer[i].prescale);
}
return ret;
}
void init_main(void)
{
u32 i;
for(i = 0; i < 4; i++)
{
dma[i].start_type = DMA_INACTIVE;
dma[i].direct_sound_channel = DMA_NO_DIRECT_SOUND;
timer[i].status = TIMER_INACTIVE;
timer[i].reload = 0x10000;
}
timer[0].direct_sound_channels = TIMER_DS_CHANNEL_BOTH;
timer[1].direct_sound_channels = TIMER_DS_CHANNEL_NONE;
cpu_ticks = 0;
execute_cycles = 960;
video_count = 960;
#ifdef HAVE_DYNAREC
init_emitter(gamepak_must_swap());
init_caches();
#endif
}
u32 function_cc update_gba(int remaining_cycles)
{
irq_type irq_raised = IRQ_NONE;
int dma_cycles;
trace_update_gba(remaining_cycles);
remaining_cycles = MAX(remaining_cycles, -64);
do
{
unsigned i;
// Number of cycles we ask to run - cycles that we did not execute
// (remaining_cycles can be negative and should be close to zero)
unsigned completed_cycles = execute_cycles - remaining_cycles;
cpu_ticks += completed_cycles;
remaining_cycles = 0;
reg[CHANGED_PC_STATUS] = 0;
reg[COMPLETED_FRAME] = 0;
if(gbc_sound_update)
{
gbc_update_count++;
update_gbc_sound(cpu_ticks);
gbc_sound_update = 0;
}
// Timers can trigger DMA (usually sound) and consume cycles
dma_cycles = update_timers(&irq_raised, completed_cycles);
video_count -= completed_cycles;
if(video_count <= 0)
{
u32 vcount = read_ioreg(REG_VCOUNT);
u32 dispstat = read_ioreg(REG_DISPSTAT);
if((dispstat & 0x02) == 0)
{
// Transition from hrefresh to hblank
video_count += (272);
dispstat |= 0x02;
if((dispstat & 0x01) == 0)
{
u32 i;
if(reg[OAM_UPDATED])
oam_update_count++;
update_scanline();
// If in visible area also fire HDMA
for(i = 0; i < 4; i++)
{
if(dma[i].start_type == DMA_START_HBLANK)
dma_transfer(i, &dma_cycles);
}
}
if(dispstat & 0x10)
irq_raised |= IRQ_HBLANK;
}
else
{
// Transition from hblank to next line
video_count += 960;
dispstat &= ~0x02;
vcount++;
if(vcount == 160)
{
// Transition from vrefresh to vblank
u32 i;
dispstat |= 0x01;
if(dispstat & 0x8)
{
irq_raised |= IRQ_VBLANK;
}
video_reload_counters();
for(i = 0; i < 4; i++)
{
if(dma[i].start_type == DMA_START_VBLANK)
dma_transfer(i, &dma_cycles);
}
}
else
if(vcount == 228)
{
// Transition from vblank to next screen
dispstat &= ~0x01;
/* printf("frame update (%x), %d instructions total, %d RAM flushes\n",
reg[REG_PC], instruction_count - last_frame, flush_ram_count);
last_frame = instruction_count;
*/
/* printf("%d gbc audio updates\n", gbc_update_count);
printf("%d oam updates\n", oam_update_count); */
gbc_update_count = 0;
oam_update_count = 0;
flush_ram_count = 0;
update_gbc_sound(cpu_ticks);
gbc_sound_update = 0;
/* If there's no cheat hook, run on vblank! */
if (cheat_master_hook == ~0U)
process_cheats();
vcount = 0;
// We completed a frame, tell the dynarec to exit to the main thread
reg[COMPLETED_FRAME] = 1;
}
if(vcount == (dispstat >> 8))
{
// vcount trigger
dispstat |= 0x04;
if(dispstat & 0x20)
{
irq_raised |= IRQ_VCOUNT;
}
}
else
dispstat &= ~0x04;
write_ioreg(REG_VCOUNT, vcount);
}
write_ioreg(REG_DISPSTAT, dispstat);
}
// Flag any V/H blank interrupts.
if (irq_raised)
flag_interrupt(irq_raised);
// Raise any pending interrupts. This changes the CPU mode.
check_and_raise_interrupts();
execute_cycles = MAX(video_count, 0);
for (i = 0; i < 4; i++)
{
if(timer[i].status != TIMER_PRESCALE)
continue;
if(timer[i].count < execute_cycles)
execute_cycles = timer[i].count;
}
} while(reg[CPU_HALT_STATE] != CPU_ACTIVE && !reg[COMPLETED_FRAME]);
// We voluntarily limit this. It is not accurate but it would be much harder.
dma_cycles = MIN(64, dma_cycles);
dma_cycles = MIN(execute_cycles, dma_cycles);
return execute_cycles - dma_cycles;
}
void reset_gba(void)
{
init_memory();
init_main();
init_cpu();
reset_sound();
}
#ifdef TRACE_REGISTERS
void print_regs(void)
{
printf("R0=%08x R1=%08x R2=%08x R3=%08x "
"R4=%08x R5=%08x R6=%08x R7=%08x "
"R8=%08x R9=%08x R10=%08x R11=%08x "
"R12=%08x R13=%08x R14=%08x\n",
reg[0], reg[1], reg[2], reg[3],
reg[4], reg[5], reg[6], reg[7],
reg[8], reg[9], reg[10], reg[11],
reg[12], reg[13], reg[14]);
}
#endif
bool main_read_savestate(const u8 *src)
{
int i;
const u8 *p1 = bson_find_key(src, "emu");
const u8 *p2 = bson_find_key(src, "timers");
if (!p1 || !p2)
return false;
if (!(bson_read_int32(p1, "cpu-ticks", &cpu_ticks) &&
bson_read_int32(p1, "exec-cycles", &execute_cycles) &&
bson_read_int32(p1, "video-count", (u32*)&video_count)))
return false;
for (i = 0; i < 4; i++)
{
char tname[2] = {'0' + i, 0};
const u8 *p = bson_find_key(p2, tname);
if (!(
bson_read_int32(p, "count", (u32*)&timer[i].count) &&
bson_read_int32(p, "reload", &timer[i].reload) &&
bson_read_int32(p, "prescale", &timer[i].prescale) &&
bson_read_int32(p, "freq-step", &timer[i].frequency_step) &&
bson_read_int32(p, "dsc", &timer[i].direct_sound_channels) &&
bson_read_int32(p, "irq", &timer[i].irq) &&
bson_read_int32(p, "status", &timer[i].status)))
return false;
}
return true;
}
unsigned main_write_savestate(u8* dst)
{
int i;
u8 *wbptr, *wbptr2, *startp = dst;
bson_start_document(dst, "emu", wbptr);
bson_write_int32(dst, "cpu-ticks", cpu_ticks);
bson_write_int32(dst, "exec-cycles", execute_cycles);
bson_write_int32(dst, "video-count", video_count);
bson_finish_document(dst, wbptr);
bson_start_document(dst, "timers", wbptr);
for (i = 0; i < 4; i++)
{
char tname[2] = {'0' + i, 0};
bson_start_document(dst, tname, wbptr2);
bson_write_int32(dst, "count", timer[i].count);
bson_write_int32(dst, "reload", timer[i].reload);
bson_write_int32(dst, "prescale", timer[i].prescale);
bson_write_int32(dst, "freq-step", timer[i].frequency_step);
bson_write_int32(dst, "dsc", timer[i].direct_sound_channels);
bson_write_int32(dst, "irq", timer[i].irq);
bson_write_int32(dst, "status", timer[i].status);
bson_finish_document(dst, wbptr2);
}
bson_finish_document(dst, wbptr);
return (unsigned int)(dst - startp);
}
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