ESCC: connect NULL and STDIO backends.

devices/serial/chario.cpp

@@ -0,0 +1,145 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-22 divingkatae and maximum
+                      (theweirdo)     spatium
+
+(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
+
+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 3 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, see <https://www.gnu.org/licenses/>.
+*/
+
+/** Character I/O backend implementations. */
+
+#include <devices/serial/chario.h>
+#include <loguru.hpp>
+
+#include <cinttypes>
+#include <memory>
+
+bool CharIoNull::rcv_char_available()
+{
+    return false;
+}
+
+int CharIoNull::xmit_char(uint8_t c)
+{
+    return 0;
+}
+
+int CharIoNull::rcv_char(uint8_t *c)
+{
+    *c = 0xFF;
+    return 0;
+}
+
+//======================== STDIO character I/O backend ========================
+#ifndef _WIN32
+
+#include<signal.h>
+#include <stdio.h>
+#include <termios.h>
+#include <unistd.h>
+
+struct sigaction    old_act, new_act;
+struct termios      orig_termios;
+
+void mysig_handler(int signum)
+{
+    // restore original terminal state
+    tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
+
+    // restore original signal handler for SIGINT
+    signal(SIGINT, old_act.sa_handler);
+
+    LOG_F(INFO, "Old terminal state restored, SIG#=%d", signum);
+
+    // re-post signal
+    raise(signum);
+}
+
+int CharIoStdin::rcv_enable()
+{
+    if (this->stdio_inited)
+        return 0;
+
+    // save original terminal state
+    tcgetattr(STDIN_FILENO, &orig_termios);
+
+    struct termios new_termios = orig_termios;
+
+    new_termios.c_cflag &= ~(CSIZE | PARENB);
+    new_termios.c_cflag |= CS8;
+    new_termios.c_lflag &= ~(ECHO | ICANON);
+    new_termios.c_iflag &= ~(ICRNL);
+
+    tcsetattr(STDIN_FILENO, TCSANOW, &new_termios);
+
+    // save original signal handler for SIGINT
+    //struct sigaction new_act;
+    memset(&new_act, 0, sizeof(new_act));
+    new_act.sa_handler = mysig_handler;
+    sigaction(SIGINT, &new_act, &old_act);
+
+    // redirect SIGINT to new handler
+    //signal(SIGINT, mysig_handler);
+
+    this->stdio_inited = true;
+
+    return 0;
+}
+
+void CharIoStdin::rcv_disable()
+{
+    if (!this->stdio_inited)
+        return;
+
+    // restore original terminal state
+    tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
+
+    // restore original signal handler for SIGINT
+    signal(SIGINT, old_act.sa_handler);
+
+    this->stdio_inited = false;
+}
+
+bool CharIoStdin::rcv_char_available()
+{
+    fd_set readfds;
+    FD_ZERO(&readfds);
+    FD_SET(STDIN_FILENO, &readfds);
+    fd_set savefds = readfds;
+
+    struct timeval timeout;
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 0;
+
+    int chr;
+
+    int sel_rv = select(1, &readfds, NULL, NULL, &timeout);
+    return sel_rv > 0;
+}
+
+int CharIoStdin::xmit_char(uint8_t c)
+{
+    write(STDOUT_FILENO, &c, 1);
+    return 0;
+}
+
+int CharIoStdin::rcv_char(uint8_t *c)
+{
+    read(STDIN_FILENO, c, 1);
+    return 0;
+}
+
+#endif // _WIN32

devices/serial/chario.h

@@ -0,0 +1,78 @@
+/*
+DingusPPC - The Experimental PowerPC Macintosh emulator
+Copyright (C) 2018-22 divingkatae and maximum
+                      (theweirdo)     spatium
+
+(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
+
+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 3 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, see <https://www.gnu.org/licenses/>.
+*/
+
+/** Character I/O definitions. */
+
+#ifndef CHAR_IO_H
+#define CHAR_IO_H
+
+#include <cinttypes>
+
+#ifndef _WIN32
+#include <termios.h>
+#endif
+
+enum {
+    CHARIO_BE_NULL  = 0, // NULL backend: swallows everything, receives nothing
+    CHARIO_BE_STDIO = 1, // STDIO backend: uses STDIN for input and STDOUT for output
+};
+
+/** Interface for character I/O backends. */
+class CharIoBackEnd {
+public:
+    CharIoBackEnd() = default;
+    virtual ~CharIoBackEnd() = default;
+
+    virtual int rcv_enable() { return 0; };
+    virtual void rcv_disable() {};
+    virtual bool rcv_char_available() = 0;
+    virtual int xmit_char(uint8_t c) = 0;
+    virtual int rcv_char(uint8_t *c) = 0;
+};
+
+/** Null character I/O backend. */
+class CharIoNull : public CharIoBackEnd {
+public:
+    CharIoNull()  = default;
+    ~CharIoNull() = default;
+
+    bool rcv_char_available();
+    int xmit_char(uint8_t c);
+    int rcv_char(uint8_t *c);
+};
+
+/** Stdin character I/O backend. */
+class CharIoStdin : public CharIoBackEnd  {
+public:
+    CharIoStdin() { this->stdio_inited = false; };
+    ~CharIoStdin() = default;
+
+    int rcv_enable();
+    void rcv_disable();
+    bool rcv_char_available();
+    int xmit_char(uint8_t c);
+    int rcv_char(uint8_t *c);
+
+private:
+    bool    stdio_inited;
+};
+
+#endif // CHAR_IO_H

devices/serial/escc.cpp

@@ -21,11 +21,14 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 /** @file Enhanced Serial Communications Controller (ESCC) emulation. */
 
-#include "escc.h"
+#include <devices/serial/chario.h>
+#include <devices/serial/escc.h>
 #include <loguru.hpp>
+#include <machines/machineproperties.h>
 
 #include <cinttypes>
 #include <memory>
+#include <string>
 
 /** Remap the compatible addressing scheme to MacRISC one. */
 const uint8_t compat_to_macrisc[6] = {
@@ -36,9 +39,17 @@ const uint8_t compat_to_macrisc[6] = {
 
 EsccController::EsccController()
 {
+    // allocate channels
     this->ch_a = std::unique_ptr<EsccChannel> (new EsccChannel("A"));
     this->ch_b = std::unique_ptr<EsccChannel> (new EsccChannel("B"));
 
+    // attach backends
+    std::string backend_name = GET_STR_PROP("serial_backend");
+
+    this->ch_a->attach_backend(
+        (backend_name == "stdio") ? CHARIO_BE_STDIO : CHARIO_BE_NULL);
+    this->ch_b->attach_backend(CHARIO_BE_NULL);
+
     this->reg_ptr = 0;
 }
 
@@ -144,9 +155,25 @@ void EsccController::write_internal(EsccChannel *ch, uint8_t value)
 }
 
 // ======================== ESCC Channel methods ==============================
+void EsccChannel::attach_backend(int id)
+{
+    switch(id) {
+    case CHARIO_BE_NULL:
+        this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoNull);
+        break;
+    case CHARIO_BE_STDIO:
+        this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoStdin);
+        break;
+    default:
+        LOG_F(ERROR, "ESCC: unknown backend ID %d, using NULL instead", id);
+        this->chario = std::unique_ptr<CharIoBackEnd> (new CharIoNull);
+    }
+}
 
 void EsccChannel::reset(bool hw_reset)
 {
+    this->chario->rcv_disable();
+
     this->write_regs[1] &= 0x24;
     this->write_regs[3] &= 0xFE;
     this->write_regs[4] |= 0x04;
@@ -184,15 +211,22 @@ void EsccChannel::write_reg(int reg_num, uint8_t value)
 {
     switch (reg_num) {
     case 3:
-        if (value & 0x11) {
-            if ((this->write_regs[3] ^ value) & 0x10) {
-                this->write_regs[3] |= 0x10;
-                this->read_regs[0] |= 0x10; // set SYNC_HUNT flag
-                LOG_F(9, "ESCC: Hunt mode entered.");
-            }
+        if ((this->write_regs[3] ^ value) & 0x10) {
+            this->write_regs[3] |= 0x10;
+            this->read_regs[0] |= 0x10; // set SYNC_HUNT flag
+            LOG_F(9, "ESCC: Hunt mode entered.");
+        }
+        if ((this->write_regs[3] ^ value) & 1) {
             if (value & 1) {
                 this->write_regs[3] |= 0x1;
+                this->chario->rcv_enable();
                 LOG_F(9, "ESCC: receiver enabled.");
+            } else {
+                this->write_regs[3] ^= 0x1;
+                this->chario->rcv_disable();
+                LOG_F(9, "ESCC: receiver disabled.");
+                this->write_regs[3] |= 0x10; // enter HUNT mode
+                this->read_regs[0] |= 0x10; // set SYNC_HUNT flag
             }
         }
         this->write_regs[3] = (this->write_regs[3] & 0x11) | (value & 0xEE);
@@ -205,6 +239,8 @@ void EsccChannel::write_reg(int reg_num, uint8_t value)
         break;
     case 14:
         switch (value >> 5) {
+        case DPLL_NULL_CMD:
+            break;
         case DPLL_ENTER_SRC_MODE:
             this->dpll_active = 1;
             this->read_regs[10] &= 0x3F;
@@ -245,16 +281,28 @@ void EsccChannel::write_reg(int reg_num, uint8_t value)
 
 uint8_t EsccChannel::read_reg(int reg_num)
 {
+    if (!reg_num) {
+        if (this->chario->rcv_char_available()) {
+            this->read_regs[0] |= 1;
+        }
+    }
     return this->read_regs[reg_num];
 }
 
 void EsccChannel::send_byte(uint8_t value)
 {
-    // Put one byte into the Data FIFO
+    // TODO: put one byte into the Data FIFO
+
+    this->chario->xmit_char(value);
 }
 
 uint8_t EsccChannel::receive_byte()
 {
-    // Remove one byte from the Receive FIFO
-    return 0xFF;
+    // TODO: remove one byte from the Receive FIFO
+
+    uint8_t c;
+
+    this->chario->rcv_char(&c);
+    this->read_regs[0] &= ~1;
+    return c;
 }

devices/serial/escc.h

@@ -24,6 +24,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #ifndef ESCC_H
 #define ESCC_H
 
+#include <devices/serial/chario.h>
+
 #include <cinttypes>
 #include <memory>
 #include <string>
@@ -71,6 +73,7 @@ enum {
 
 /** DPLL commands in WR14. */
 enum {
+    DPLL_NULL_CMD           = 0,
     DPLL_ENTER_SRC_MODE     = 1,
     DPLL_RST_MISSING_CLK    = 2,
     DPLL_DISABLE            = 3,
@@ -91,6 +94,7 @@ public:
     EsccChannel(std::string name) { this->name = name; };
     ~EsccChannel() = default;
 
+    void attach_backend(int id);
     void reset(bool hw_reset);
     uint8_t read_reg(int reg_num);
     void write_reg(int reg_num, uint8_t value);
@@ -107,6 +111,8 @@ private:
     uint8_t         dpll_clock_src;
     uint8_t         brg_active;
     uint8_t         brg_clock_src;
+
+    std::unique_ptr<CharIoBackEnd>  chario;
 };
 
 /** ESCC Controller class. */

machines/machinefactory.cpp

@@ -1,6 +1,6 @@
 /*
 DingusPPC - The Experimental PowerPC Macintosh emulator
-Copyright (C) 2018-21 divingkatae and maximum
+Copyright (C) 2018-22 divingkatae and maximum
                       (theweirdo)     spatium
 
 (Contact divingkatae#1017 or powermax#2286 on Discord for more info)
@@ -69,6 +69,8 @@ static const map<uint32_t, std::tuple<string, const char*>> rom_identity = {
 
 static const vector<string> WriteToggle = {"ON", "on", "OFF", "off"};
 
+static const vector<string> CharIoBackends = {"null", "stdio"};
+
 static const PropMap CatalystSettings = {
     {"rambank1_size",
         new IntProperty(16, vector<uint32_t>({4, 8, 16, 32, 64, 128}))},
@@ -84,6 +86,7 @@ static const PropMap CatalystSettings = {
         new StrProperty("")},
     {"fdd_img",
         new StrProperty("")},
+    {"serial_backend", new StrProperty("null", CharIoBackends)},
 };
 
 static const PropMap GossamerSettings = {
@@ -100,6 +103,7 @@ static const PropMap GossamerSettings = {
     {"fdd_img",
         new StrProperty("")},
     {"fdd_wr_prot", new StrProperty("OFF", WriteToggle)},
+    {"serial_backend", new StrProperty("null", CharIoBackends)},
 };
 
 /** Monitors supported by the PDM on-board video. */
@@ -121,6 +125,7 @@ static const PropMap PDMSettings = {
         new StrProperty("")},
     {"fdd_wr_prot",
         new StrProperty("OFF", WriteToggle)},
+    {"serial_backend", new StrProperty("null", CharIoBackends)},
 };
 
 static const map<string, string> PropHelp = {
@@ -132,6 +137,7 @@ static const map<string, string> PropHelp = {
     {"fdd_img",         "specifies path to floppy disk image"},
     {"fdd_wr_prot",     "toggles floppy disks write protection"},
     {"mon_id",          "specifies which monitor to emulate"},
+    {"serial_backend",  "specifies the backend for the serial port"},
 };
 
 static const map<string, tuple<PropMap, function<int(string&)>, string>> machines = {