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-rw-r--r--genesis.c46
-rw-r--r--io.c194
-rw-r--r--io.h16
-rw-r--r--vdp.h2
4 files changed, 232 insertions, 26 deletions
diff --git a/genesis.c b/genesis.c
index 5d50394..a73b6be 100644
--- a/genesis.c
+++ b/genesis.c
@@ -234,13 +234,14 @@ static void adjust_int_cycle(m68k_context * context, vdp_context * v_context)
context->sync_cycle = context->current_cycle + gen->max_cycles;
}
context->int_cycle = CYCLE_NEVER;
- if ((context->status & 0x7) < 6) {
+ uint8_t mask = context->status & 0x7;
+ if (mask < 6) {
uint32_t next_vint = vdp_next_vint(v_context);
if (next_vint != CYCLE_NEVER) {
context->int_cycle = next_vint;
context->int_num = 6;
}
- if ((context->status & 0x7) < 4) {
+ if (mask < 4) {
uint32_t next_hint = vdp_next_hint(v_context);
if (next_hint != CYCLE_NEVER) {
next_hint = next_hint < context->current_cycle ? context->current_cycle : next_hint;
@@ -250,6 +251,21 @@ static void adjust_int_cycle(m68k_context * context, vdp_context * v_context)
}
}
+ if (mask < 2 && (v_context->regs[REG_MODE_3] & BIT_EINT_EN)) {
+ uint32_t next_eint_port0 = io_next_interrupt(gen->io.ports, context->current_cycle);
+ uint32_t next_eint_port1 = io_next_interrupt(gen->io.ports + 1, context->current_cycle);
+ uint32_t next_eint_port2 = io_next_interrupt(gen->io.ports + 2, context->current_cycle);
+ uint32_t next_eint = next_eint_port0 < next_eint_port1
+ ? (next_eint_port0 < next_eint_port2 ? next_eint_port0 : next_eint_port2)
+ : (next_eint_port1 < next_eint_port2 ? next_eint_port1 : next_eint_port2);
+ if (next_eint != CYCLE_NEVER) {
+ next_eint = next_eint < context->current_cycle ? context->current_cycle : next_eint;
+ if (next_eint < context->int_cycle) {
+ context->int_cycle = next_eint;
+ context->int_num = 2;
+ }
+ }
+ }
}
}
if (context->int_cycle > context->current_cycle && context->int_pending == INT_PENDING_SR_CHANGE) {
@@ -379,6 +395,9 @@ m68k_context * sync_components(m68k_context * context, uint32_t address)
sync_z80(z_context, mclks);
sync_sound(gen, mclks);
vdp_run_context(v_context, mclks);
+ io_run(gen->io.ports, mclks);
+ io_run(gen->io.ports + 1, mclks);
+ io_run(gen->io.ports + 2, mclks);
if (mclks >= gen->reset_cycle) {
gen->reset_requested = 1;
context->should_return = 1;
@@ -793,7 +812,7 @@ static m68k_context * io_write(uint32_t location, m68k_context * context, uint8_
io_control_write(gen->io.ports+2, value, context->current_cycle);
break;
case 0x7:
- gen->io.ports[0].serial_out = value;
+ io_tx_write(gen->io.ports, value, context->current_cycle);
break;
case 0x8:
case 0xB:
@@ -801,19 +820,20 @@ static m68k_context * io_write(uint32_t location, m68k_context * context, uint8_
//serial input port is not writeable
break;
case 0x9:
+ io_sctrl_write(gen->io.ports, value, context->current_cycle);
gen->io.ports[0].serial_ctrl = value;
break;
case 0xA:
- gen->io.ports[1].serial_out = value;
+ io_tx_write(gen->io.ports + 1, value, context->current_cycle);
break;
case 0xC:
- gen->io.ports[1].serial_ctrl = value;
+ io_sctrl_write(gen->io.ports + 1, value, context->current_cycle);
break;
case 0xD:
- gen->io.ports[2].serial_out = value;
+ io_tx_write(gen->io.ports + 2, value, context->current_cycle);
break;
case 0xF:
- gen->io.ports[2].serial_ctrl = value;
+ io_sctrl_write(gen->io.ports + 2, value, context->current_cycle);
break;
}
} else {
@@ -949,28 +969,28 @@ static uint8_t io_read(uint32_t location, m68k_context * context)
value = gen->io.ports[0].serial_out;
break;
case 0x8:
- value = gen->io.ports[0].serial_in;
+ value = io_rx_read(gen->io.ports, context->current_cycle);
break;
case 0x9:
- value = gen->io.ports[0].serial_ctrl;
+ value = io_sctrl_read(gen->io.ports, context->current_cycle);
break;
case 0xA:
value = gen->io.ports[1].serial_out;
break;
case 0xB:
- value = gen->io.ports[1].serial_in;
+ value = io_rx_read(gen->io.ports + 1, context->current_cycle);
break;
case 0xC:
- value = gen->io.ports[1].serial_ctrl;
+ value = io_sctrl_read(gen->io.ports, context->current_cycle);
break;
case 0xD:
value = gen->io.ports[2].serial_out;
break;
case 0xE:
- value = gen->io.ports[2].serial_in;
+ value = io_rx_read(gen->io.ports + 1, context->current_cycle);
break;
case 0xF:
- value = gen->io.ports[2].serial_ctrl;
+ value = io_sctrl_read(gen->io.ports, context->current_cycle);
break;
default:
value = get_open_bus_value(&gen->header) >> 8;
diff --git a/io.c b/io.c
index 273c50d..f93eb38 100644
--- a/io.c
+++ b/io.c
@@ -39,7 +39,8 @@ const char * device_type_names[] = {
"EA 4-way Play cable A",
"EA 4-way Play cable B",
"Sega Parallel Transfer Board",
- "Generic Device"
+ "Generic Device",
+ "Generic Serial"
};
#define GAMEPAD_TH0 0
@@ -210,8 +211,20 @@ uint8_t io_has_keyboard(sega_io *io)
return find_keyboard(io) != NULL;
}
+static void set_serial_clock(io_port *port)
+{
+ switch(port->serial_ctrl >> 6)
+ {
+ case 0: port->serial_divider = 11186; break; //4800 bps
+ case 1: port->serial_divider = 22372; break; //2400 bps
+ case 2: port->serial_divider = 44744; break; //1200 bps
+ case 3: port->serial_divider = 178976; break; //300 bps
+ }
+}
+
void process_device(char * device_type, io_port * port)
{
+ set_serial_clock(port);
//assuming that the io_port struct has been zeroed if this is the first time this has been called
if (!device_type)
{
@@ -272,6 +285,12 @@ void process_device(char * device_type, io_port * port)
port->device.stream.data_fd = -1;
port->device.stream.listen_fd = -1;
}
+ } else if(!strcmp(device_type, "serial")) {
+ if (port->device_type != IO_GENERIC_SERIAL) {
+ port->device_type = IO_GENERIC_SERIAL;
+ port->device.stream.data_fd = -1;
+ port->device.stream.listen_fd = -1;
+ }
}
}
@@ -354,7 +373,7 @@ void setup_io_devices(tern_node * config, rom_info *rom, sega_io *io)
}
}
}
- } else if (ports[i].device_type == IO_GENERIC && ports[i].device.stream.data_fd == -1) {
+ } else if (ports[i].device_type == IO_GENERIC || ports[i].device_type == IO_GENERIC_SERIAL && ports[i].device.stream.data_fd == -1) {
char *sock_name = tern_find_path(config, "io\0socket\0", TVAL_PTR).ptrval;
if (!sock_name)
{
@@ -427,7 +446,6 @@ void mouse_check_ready(io_port *port, uint32_t current_cycle)
}
}
-uint32_t last_poll_cycle;
void io_adjust_cycles(io_port * port, uint32_t current_cycle, uint32_t deduction)
{
/*uint8_t control = pad->control | 0x80;
@@ -459,25 +477,80 @@ void io_adjust_cycles(io_port * port, uint32_t current_cycle, uint32_t deduction
}
}
}
- if (last_poll_cycle >= deduction) {
- last_poll_cycle -= deduction;
+ if (port->transmit_end >= deduction) {
+ port->transmit_end -= deduction;
+ } else {
+ port->transmit_end = 0;
+ }
+ if (port->receive_end >= deduction) {
+ port->receive_end -= deduction;
} else {
- last_poll_cycle = 0;
+ port->receive_end = 0;
+ }
+ if (port->last_poll_cycle >= deduction) {
+ port->last_poll_cycle -= deduction;
+ } else {
+ port->last_poll_cycle = 0;
}
}
#ifndef _WIN32
-static void wait_for_connection(io_port * port)
+static void wait_for_connection(io_port *port)
{
if (port->device.stream.data_fd == -1)
{
- debug_message("Waiting for socket connection...");
+ debug_message("Waiting for socket connection...\n");
port->device.stream.data_fd = accept(port->device.stream.listen_fd, NULL, NULL);
fcntl(port->device.stream.data_fd, F_SETFL, O_NONBLOCK | O_RDWR);
}
}
-static void service_pipe(io_port * port)
+static void poll_for_connection(io_port *port)
+{
+ if (port->device.stream.data_fd == -1)
+ {
+ fcntl(port->device.stream.listen_fd, F_SETFL, O_NONBLOCK | O_RDWR);
+ port->device.stream.data_fd = accept(port->device.stream.listen_fd, NULL, NULL);
+ fcntl(port->device.stream.listen_fd, F_SETFL, O_RDWR);
+ if (port->device.stream.data_fd != -1) {
+ fcntl(port->device.stream.data_fd, F_SETFL, O_NONBLOCK | O_RDWR);
+ }
+ }
+}
+
+static void write_serial_byte(io_port *port)
+{
+ fcntl(port->device.stream.data_fd, F_SETFL, O_RDWR);
+ for (int sent = 0; sent != sizeof(port->serial_transmitting);)
+ {
+ sent = send(port->device.stream.data_fd, &port->serial_transmitting, sizeof(port->serial_transmitting), 0);
+ if (sent < 0) {
+ close(port->device.stream.data_fd);
+ port->device.stream.data_fd = -1;
+ wait_for_connection(port);
+ fcntl(port->device.stream.data_fd, F_SETFL, O_RDWR);
+ }
+ }
+ fcntl(port->device.stream.data_fd, F_SETFL, O_NONBLOCK | O_RDWR);
+}
+
+static void read_serial_byte(io_port *port)
+{
+ poll_for_connection(port);
+ if (port->device.stream.data_fd == -1) {
+ return;
+ }
+ int read = recv(port->device.stream.data_fd, &port->serial_receiving, sizeof(port->serial_receiving), 0);
+ if (read < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
+ close(port->device.stream.data_fd);
+ port->device.stream.data_fd = -1;
+ }
+ if (read > 0) {
+ port->receive_end = port->serial_cycle + 10 * port->serial_divider;
+ }
+}
+
+static void service_pipe(io_port *port)
{
uint8_t value;
int numRead = read(port->device.stream.data_fd, &value, sizeof(value));
@@ -576,6 +649,61 @@ enum {
KB_WRITE
};
+enum {
+ SCTRL_BIT_TX_FULL = 1,
+ SCTRL_BIT_RX_READY = 2,
+ SCTRL_BIT_RX_ERROR = 4,
+ SCTRL_BIT_RX_INTEN = 8,
+ SCTRL_BIT_TX_ENABLE = 0x10,
+ SCTRL_BIT_RX_ENABLE = 0x20
+};
+
+void io_run(io_port *port, uint32_t current_cycle)
+{
+ uint32_t new_serial_cycle = ((current_cycle - port->serial_cycle) / port->serial_divider) * port->serial_divider + port->serial_cycle;
+ if (port->transmit_end && port->transmit_end <= new_serial_cycle) {
+ port->transmit_end = 0;
+
+ if (port->serial_ctrl & SCTRL_BIT_TX_ENABLE) {
+ switch (port->device_type)
+ {
+#ifndef _WIN32
+ case IO_GENERIC_SERIAL:
+ write_serial_byte(port);
+ break;
+#endif
+ //TODO: think about how serial mode might interact with non-serial peripherals
+ }
+ }
+ }
+ if (!port->transmit_end && new_serial_cycle != port->serial_cycle && (port->serial_ctrl & SCTRL_BIT_TX_FULL)) {
+ //there's a transmit byte pending and no byte is currently being sent
+ port->serial_transmitting = port->serial_out;
+ port->serial_ctrl &= ~SCTRL_BIT_TX_FULL;
+ //1 start bit, 8 data bits and 1 stop bit
+ port->transmit_end = new_serial_cycle + 10 * port->serial_divider;
+ }
+ port->serial_cycle = new_serial_cycle;
+ if (port->serial_ctrl && SCTRL_BIT_RX_ENABLE) {
+ if (port->receive_end && new_serial_cycle >= port->receive_end) {
+ port->serial_in = port->serial_receiving;
+ port->serial_ctrl |= SCTRL_BIT_RX_READY;
+ port->receive_end = 0;
+ }
+ if (!port->receive_end) {
+ switch(port->device_type)
+ {
+#ifndef _WIN32
+ case IO_GENERIC_SERIAL:
+ read_serial_byte(port);
+ break;
+#endif
+ //TODO: think about how serial mode might interact with non-serial peripherals
+ }
+ }
+ }
+}
+
void io_control_write(io_port *port, uint8_t value, uint32_t current_cycle)
{
uint8_t changes = value ^ port->control;
@@ -723,6 +851,20 @@ void io_data_write(io_port * port, uint8_t value, uint32_t current_cycle)
}
+void io_tx_write(io_port *port, uint8_t value, uint32_t current_cycle)
+{
+ io_run(port, current_cycle);
+ port->serial_out = value;
+ port->serial_ctrl |= SCTRL_BIT_TX_FULL;
+}
+
+void io_sctrl_write(io_port *port, uint8_t value, uint32_t current_cycle)
+{
+ io_run(port, current_cycle);
+ port->serial_ctrl = (port->serial_ctrl & 0x7) | (value & 0xF8);
+ set_serial_clock(port);
+}
+
uint8_t get_scancode_bytes(io_port *port)
{
if (port->device.keyboard.read_pos == 0xFF) {
@@ -766,9 +908,9 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle)
uint8_t th = output & 0x40;
uint8_t input;
uint8_t device_driven;
- if (current_cycle - last_poll_cycle > MIN_POLL_INTERVAL) {
+ if (current_cycle - port->last_poll_cycle > MIN_POLL_INTERVAL) {
process_events();
- last_poll_cycle = current_cycle;
+ port->last_poll_cycle = current_cycle;
}
switch (port->device_type)
{
@@ -1049,6 +1191,36 @@ uint8_t io_data_read(io_port * port, uint32_t current_cycle)
return value;
}
+uint8_t io_rx_read(io_port * port, uint32_t current_cycle)
+{
+ io_run(port, current_cycle);
+ port->serial_ctrl &= ~SCTRL_BIT_RX_READY;
+ return port->serial_in;
+}
+
+uint8_t io_sctrl_read(io_port *port, uint32_t current_cycle)
+{
+ io_run(port, current_cycle);
+ return port->serial_ctrl;
+}
+
+uint32_t io_next_interrupt(io_port *port, uint32_t current_cycle)
+{
+ if (!(port->control & 0x80)) {
+ return CYCLE_NEVER;
+ }
+ if (port->serial_ctrl & SCTRL_BIT_RX_INTEN) {
+ if (port->serial_ctrl & SCTRL_BIT_RX_READY) {
+ return current_cycle;
+ }
+ if ((port->serial_ctrl & SCTRL_BIT_RX_ENABLE) && port->receive_end) {
+ return port->receive_end;
+ }
+ }
+ //TODO: handle external interrupts from TH transitions
+ return CYCLE_NEVER;
+}
+
void io_serialize(io_port *port, serialize_buffer *buf)
{
save_int8(buf, port->output);
diff --git a/io.h b/io.h
index 23affc7..00f1528 100644
--- a/io.h
+++ b/io.h
@@ -24,7 +24,8 @@ enum {
IO_EA_MULTI_A,
IO_EA_MULTI_B,
IO_SEGA_PARALLEL,
- IO_GENERIC
+ IO_GENERIC,
+ IO_GENERIC_SERIAL
};
typedef struct {
@@ -62,8 +63,15 @@ typedef struct {
uint8_t control;
uint8_t input[3];
uint32_t slow_rise_start[8];
+ uint32_t serial_cycle;
+ uint32_t serial_divider;
+ uint32_t last_poll_cycle;
+ uint32_t transmit_end;
+ uint32_t receive_end;
uint8_t serial_out;
+ uint8_t serial_transmitting;
uint8_t serial_in;
+ uint8_t serial_receiving;
uint8_t serial_ctrl;
uint8_t device_type;
} io_port;
@@ -106,9 +114,15 @@ enum {
void setup_io_devices(tern_node * config, rom_info *rom, sega_io *io);
void io_adjust_cycles(io_port * pad, uint32_t current_cycle, uint32_t deduction);
+void io_run(io_port *port, uint32_t current_cycle);
void io_control_write(io_port *port, uint8_t value, uint32_t current_cycle);
void io_data_write(io_port * pad, uint8_t value, uint32_t current_cycle);
+void io_tx_write(io_port *port, uint8_t value, uint32_t current_cycle);
+void io_sctrl_write(io_port *port, uint8_t value, uint32_t current_cycle);
uint8_t io_data_read(io_port * pad, uint32_t current_cycle);
+uint8_t io_rx_read(io_port * port, uint32_t current_cycle);
+uint8_t io_sctrl_read(io_port *port, uint32_t current_cycle);
+uint32_t io_next_interrupt(io_port *port, uint32_t current_cycle);
void io_serialize(io_port *port, serialize_buffer *buf);
void io_deserialize(deserialize_buffer *buf, void *vport);
diff --git a/vdp.h b/vdp.h
index c33b42f..aca1cca 100644
--- a/vdp.h
+++ b/vdp.h
@@ -118,7 +118,7 @@ enum {
#define BIT_SPRITE_SZ 0x02
//Mode reg 3
-#define BIT_EINT_EN 0x10
+#define BIT_EINT_EN 0x08
#define BIT_VSCROLL 0x04
//Mode reg 4
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-19 12:33:11 +0000