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#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include "sms.h"
#include "blastem.h"
#include "render.h"
#include "util.h"
#include "debug.h"
static void *memory_io_write(uint32_t location, void *vcontext, uint8_t value)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
if (location & 1) {
sms->io.ports[0].control = ~(value << 5 & 0x60);
sms->io.ports[1].control = ~(value << 3 & 0x60);
io_data_write(sms->io.ports, value << 1, z80->current_cycle);
io_data_write(sms->io.ports + 1, value >> 1, z80->current_cycle);
} else {
//TODO: memory control write
}
return vcontext;
}
static uint8_t hv_read(uint32_t location, void *vcontext)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
vdp_run_context(sms->vdp, z80->current_cycle);
uint16_t hv = vdp_hv_counter_read(sms->vdp);
if (location & 1) {
return hv;
} else {
return hv >> 8;
}
}
static void *sms_psg_write(uint32_t location, void *vcontext, uint8_t value)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
psg_run(sms->psg, z80->current_cycle);
psg_write(sms->psg, value);
return vcontext;
}
static void update_interrupts(sms_context *sms)
{
uint32_t vint = vdp_next_vint(sms->vdp);
uint32_t hint = vdp_next_hint(sms->vdp);
sms->z80->int_pulse_start = vint < hint ? vint : hint;
}
static uint8_t vdp_read(uint32_t location, void *vcontext)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
vdp_run_context(sms->vdp, z80->current_cycle);
if (location & 1) {
uint8_t ret = vdp_control_port_read(sms->vdp);
sms->vdp->flags2 &= ~(FLAG2_VINT_PENDING|FLAG2_HINT_PENDING);
update_interrupts(sms);
return ret;
} else {
return vdp_data_port_read(sms->vdp);
}
}
static void *vdp_write(uint32_t location, void *vcontext, uint8_t value)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
vdp_run_context(sms->vdp, z80->current_cycle);
if (location & 1) {
vdp_control_port_write_pbc(sms->vdp, value);
update_interrupts(sms);
} else {
vdp_data_port_write_pbc(sms->vdp, value);
}
return vcontext;
}
static uint8_t io_read(uint32_t location, void *vcontext)
{
z80_context *z80 = vcontext;
sms_context *sms = z80->system;
if (location == 0xC0 || location == 0xDC) {
uint8_t port_a = io_data_read(sms->io.ports, z80->current_cycle);
uint8_t port_b = io_data_read(sms->io.ports, z80->current_cycle);
return (port_a & 0x3F) | (port_b << 6);
}
if (location == 0xC1 || location == 0xDD) {
uint8_t port_a = io_data_read(sms->io.ports, z80->current_cycle);
uint8_t port_b = io_data_read(sms->io.ports, z80->current_cycle);
return (port_a & 0x40) | (port_b >> 2 & 0xF) | (port_b << 1 & 0x80) | 0x10;
}
return 0xFF;
}
static memmap_chunk io_map[] = {
{0x00, 0x40, 0xFF, 0, 0, 0, NULL, NULL, NULL, NULL, memory_io_write},
{0x40, 0x80, 0xFF, 0, 0, 0, NULL, NULL, NULL, hv_read, sms_psg_write},
{0x80, 0xC0, 0xFF, 0, 0, 0, NULL, NULL, NULL, vdp_read, vdp_write},
{0xC0, 0x100,0xFF, 0, 0, 0, NULL, NULL, NULL, io_read, NULL}
};
static void set_speed_percent(system_header * system, uint32_t percent)
{
sms_context *context = (sms_context *)system;
uint32_t old_clock = context->master_clock;
context->master_clock = ((uint64_t)context->normal_clock * (uint64_t)percent) / 100;
psg_adjust_master_clock(context->psg, context->master_clock);
}
static void run_sms(system_header *system)
{
render_disable_ym();
sms_context *sms = (sms_context *)system;
uint32_t target_cycle = sms->z80->current_cycle + 3420*262;
while (!sms->should_return)
{
if (system->enter_debugger && sms->z80->pc) {
system->enter_debugger = 0;
zdebugger(sms->z80, sms->z80->pc);
}
z80_run(sms->z80, target_cycle);
target_cycle = sms->z80->current_cycle;
vdp_run_context(sms->vdp, target_cycle);
psg_run(sms->psg, target_cycle);
target_cycle += 3420*262;
if (target_cycle > 0x10000000) {
uint32_t adjust = sms->z80->current_cycle - 3420*262*2;
io_adjust_cycles(sms->io.ports, sms->z80->current_cycle, adjust);
io_adjust_cycles(sms->io.ports+1, sms->z80->current_cycle, adjust);
z80_adjust_cycles(sms->z80, adjust);
vdp_adjust_cycles(sms->vdp, adjust);
sms->psg->cycles -= adjust;
target_cycle -= adjust;
}
}
sms->should_return = 0;
render_enable_ym();
}
static void start_sms(system_header *system, char *statefile)
{
sms_context *sms = (sms_context *)system;
set_keybindings(&sms->io);
if (system->enter_debugger) {
system->enter_debugger = 0;
zinsert_breakpoint(sms->z80, 0, (uint8_t *)zdebugger);
}
z80_assert_reset(sms->z80, 0);
z80_clear_reset(sms->z80, 128*15);
run_sms(system);
}
static void free_sms(system_header *system)
{
sms_context *sms = (sms_context *)system;
vdp_free(sms->vdp);
z80_options_free(sms->z80->options);
free(sms->z80);
psg_free(sms->psg);
free(sms);
}
static uint16_t get_open_bus_value(system_header *system)
{
return 0xFFFF;
}
static void request_exit(system_header *system)
{
sms_context *sms = (sms_context *)system;
sms->should_return = 1;
}
static void inc_debug_mode(system_header *system)
{
sms_context *sms = (sms_context *)system;
sms->vdp->debug++;
if (sms->vdp->debug == 7) {
sms->vdp->debug = 0;
}
}
static void inc_debug_pal(system_header *system)
{
sms_context *sms = (sms_context *)system;
sms->vdp->debug_pal++;
if (sms->vdp->debug_pal == 4) {
sms->vdp->debug_pal = 0;
}
}
sms_context *alloc_configure_sms(void *rom, uint32_t rom_size, void *extra_rom, uint32_t extra_rom_size, uint32_t opts, uint8_t force_region, rom_info *info_out)
{
memset(info_out, 0, sizeof(*info_out));
sms_context *sms = calloc(1, sizeof(sms_context));
rom_size = nearest_pow2(rom_size);
uint32_t mask = rom_size >= 0xC000 ? 0xFFFF : rom_size-1;
memmap_chunk memory_map[] = {
{0x0000, 0xC000, rom_size-1, 0, 0, MMAP_READ, rom, NULL, NULL, NULL, NULL},
{0xC000, 0x10000, sizeof(sms->ram)-1, 0, 0, MMAP_READ|MMAP_WRITE|MMAP_CODE, sms->ram, NULL, NULL, NULL, NULL}
};
info_out->map = malloc(sizeof(memory_map));
memcpy(info_out->map, memory_map, sizeof(memory_map));
z80_options *zopts = malloc(sizeof(z80_options));
init_z80_opts(zopts, info_out->map, 2, io_map, 4, 15, 0xFF);
sms->z80 = init_z80_context(zopts);
sms->z80->system = sms;
char * lowpass_cutoff_str = tern_find_path(config, "audio\0lowpass_cutoff\0").ptrval;
uint32_t lowpass_cutoff = lowpass_cutoff_str ? atoi(lowpass_cutoff_str) : 3390;
//TODO: Detect region and pick master clock based off of that
sms->normal_clock = sms->master_clock = 53693175;
sms->psg = malloc(sizeof(psg_context));
psg_init(sms->psg, render_sample_rate(), sms->master_clock, 15*16, render_audio_buffer(), lowpass_cutoff);
sms->vdp = malloc(sizeof(vdp_context));
init_vdp_context(sms->vdp, 0);
sms->vdp->system = &sms->header;
info_out->save_type = SAVE_NONE;
info_out->name = strdup("Master System Game");
setup_io_devices(config, info_out, &sms->io);
sms->header.set_speed_percent = set_speed_percent;
sms->header.start_context = start_sms;
sms->header.resume_context = run_sms;
//TODO: Fill in NULL values
sms->header.load_save = NULL;
sms->header.persist_save = NULL;
sms->header.free_context = free_sms;
sms->header.get_open_bus_value = get_open_bus_value;
sms->header.request_exit = request_exit;
sms->header.inc_debug_mode = inc_debug_mode;
sms->header.inc_debug_pal = inc_debug_pal;
return sms;
}
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