Merge pull request #3504 from Cacodemon345/dec_tulip

Port DECchip 21143 "Tulip" NIC emulation from QEMU

src/include/86box/net_eeprom_nmc93cxx.h

@@ -0,0 +1,20 @@
+struct nmc93cxx_eeprom_t;
+typedef struct nmc93cxx_eeprom_t nmc93cxx_eeprom_t;
+
+typedef struct nmc93cxx_eeprom_params_t
+{
+    uint16_t nwords;
+    char* filename;
+    uint16_t* default_content;
+} nmc93cxx_eeprom_params_t;
+
+/* Read from the EEPROM. */
+uint16_t nmc93cxx_eeprom_read(nmc93cxx_eeprom_t *eeprom);
+
+/* Write to the EEPROM. */
+void nmc93cxx_eeprom_write(nmc93cxx_eeprom_t *eeprom, int eecs, int eesk, int eedi);
+
+/* Get EEPROM data array. */
+uint16_t *nmc93cxx_eeprom_data(nmc93cxx_eeprom_t *eeprom);
+
+extern const device_t nmc93cxx_device;

src/include/86box/net_tulip.h

@@ -0,0 +1 @@
+extern const device_t dec_tulip_device;

src/network/CMakeLists.txt

@@ -14,7 +14,8 @@
 #
 set(net_sources)
 list(APPEND net_sources network.c net_pcap.c net_slirp.c net_dp8390.c net_3c501.c
-    net_3c503.c net_ne2000.c net_pcnet.c net_wd8003.c net_plip.c net_event.c net_null.c)
+    net_3c503.c net_ne2000.c net_pcnet.c net_wd8003.c net_plip.c net_event.c net_null.c
+    net_eeprom_nmc93cxx.c net_tulip.c)
 
 find_package(PkgConfig REQUIRED)
 pkg_check_modules(SLIRP REQUIRED IMPORTED_TARGET slirp)

src/network/net_eeprom_nmc93cxx.c

@@ -0,0 +1,273 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Emulation of National Semiconductors NMC93Cxx EEPROMs.
+ *
+ *
+ * Authors: Cacodemon345
+ *
+ *          Copyright 2023 Cacodemon345
+ */
+
+/* Ported over from QEMU */
+
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <86box/86box.h>
+#include <86box/device.h>
+#include <86box/timer.h>
+#include <86box/nvr.h>
+#include <86box/net_eeprom_nmc93cxx.h>
+
+struct nmc93cxx_eeprom_t {
+    uint8_t  tick;
+    uint8_t  address;
+    uint8_t  command;
+    uint8_t  writable;
+
+    uint8_t eecs;
+    uint8_t eesk;
+    uint8_t eedo;
+
+    uint8_t  addrbits;
+    uint16_t size;
+    uint16_t data;
+    char filename[1024];
+    uint16_t contents[];
+};
+
+typedef struct nmc93cxx_eeprom_t nmc93cxx_eeprom_t;
+
+#define logout pclog
+
+static const char *opstring[] = {
+  "extended", "write", "read", "erase"
+};
+
+static void *
+nmc93cxx_eeprom_init_params(const device_t *info, void* params)
+{
+    uint16_t nwords = 64;
+    uint8_t addrbits = 6;
+    uint8_t filldefault = 1;
+    nmc93cxx_eeprom_params_t* params_details = (nmc93cxx_eeprom_params_t*)params;
+    nmc93cxx_eeprom_t* eeprom = NULL;
+    if (!params)
+        return NULL;
+
+    nwords = params_details->nwords;
+
+    switch (nwords) {
+    case 16:
+    case 64:
+        addrbits = 6;
+        break;
+    case 128:
+    case 256:
+        addrbits = 8;
+        break;
+    default:
+        nwords = 64;
+        addrbits = 6;
+        break;
+    }
+    eeprom = calloc(1, sizeof(nmc93cxx_eeprom_t) + ((nwords + 1) * 2));
+    if (!eeprom)
+        return NULL;
+    eeprom->size = nwords;
+    eeprom->addrbits = addrbits;
+    /* Output DO is tristate, read results in 1. */
+    eeprom->eedo = 1;
+
+    if (params_details->filename)
+    {
+        FILE* file = nvr_fopen(params_details->filename, "rb");
+        strncpy(eeprom->filename, params_details->filename, 1024);
+        if (file) {
+            filldefault = !fread(eeprom->contents, sizeof(uint16_t), nwords, file);
+            fclose(file);
+        }
+    }
+
+    if (filldefault)
+    {
+        memcpy(eeprom->contents, params_details->default_content, nwords * sizeof(uint16_t));
+    }
+
+    return eeprom;
+}
+
+void nmc93cxx_eeprom_write(nmc93cxx_eeprom_t *eeprom, int eecs, int eesk, int eedi)
+{
+    uint8_t tick = eeprom->tick;
+    uint8_t eedo = eeprom->eedo;
+    uint16_t address = eeprom->address;
+    uint8_t command = eeprom->command;
+
+    logout("CS=%u SK=%u DI=%u DO=%u, tick = %u\n",
+           eecs, eesk, eedi, eedo, tick);
+
+    if (!eeprom->eecs && eecs) {
+        /* Start chip select cycle. */
+        logout("Cycle start, waiting for 1st start bit (0)\n");
+        tick = 0;
+        command = 0x0;
+        address = 0x0;
+    } else if (eeprom->eecs && !eecs) {
+        /* End chip select cycle. This triggers write / erase. */
+        if (eeprom->writable) {
+            uint8_t subcommand = address >> (eeprom->addrbits - 2);
+            if (command == 0 && subcommand == 2) {
+                /* Erase all. */
+                for (address = 0; address < eeprom->size; address++) {
+                    eeprom->contents[address] = 0xffff;
+                }
+            } else if (command == 3) {
+                /* Erase word. */
+                eeprom->contents[address] = 0xffff;
+            } else if (tick >= 2 + 2 + eeprom->addrbits + 16) {
+                if (command == 1) {
+                    /* Write word. */
+                    eeprom->contents[address] &= eeprom->data;
+                } else if (command == 0 && subcommand == 1) {
+                    /* Write all. */
+                    for (address = 0; address < eeprom->size; address++) {
+                        eeprom->contents[address] &= eeprom->data;
+                    }
+                }
+            }
+        }
+        /* Output DO is tristate, read results in 1. */
+        eedo = 1;
+    } else if (eecs && !eeprom->eesk && eesk) {
+        /* Raising edge of clock shifts data in. */
+        if (tick == 0) {
+            /* Wait for 1st start bit. */
+            if (eedi == 0) {
+                logout("Got correct 1st start bit, waiting for 2nd start bit (1)\n");
+                tick++;
+            } else {
+                logout("wrong 1st start bit (is 1, should be 0)\n");
+                tick = 2;
+                //~ assert(!"wrong start bit");
+            }
+        } else if (tick == 1) {
+            /* Wait for 2nd start bit. */
+            if (eedi != 0) {
+                logout("Got correct 2nd start bit, getting command + address\n");
+                tick++;
+            } else {
+                logout("1st start bit is longer than needed\n");
+            }
+        } else if (tick < 2 + 2) {
+            /* Got 2 start bits, transfer 2 opcode bits. */
+            tick++;
+            command <<= 1;
+            if (eedi) {
+                command += 1;
+            }
+        } else if (tick < 2 + 2 + eeprom->addrbits) {
+            /* Got 2 start bits and 2 opcode bits, transfer all address bits. */
+            tick++;
+            address = ((address << 1) | eedi);
+            if (tick == 2 + 2 + eeprom->addrbits) {
+                logout("%s command, address = 0x%02x (value 0x%04x)\n",
+                       opstring[command], address, eeprom->contents[address]);
+                if (command == 2) {
+                    eedo = 0;
+                }
+                address = address % eeprom->size;
+                if (command == 0) {
+                    /* Command code in upper 2 bits of address. */
+                    switch (address >> (eeprom->addrbits - 2)) {
+                    case 0:
+                        logout("write disable command\n");
+                        eeprom->writable = 0;
+                        break;
+                    case 1:
+                        logout("write all command\n");
+                        break;
+                    case 2:
+                        logout("erase all command\n");
+                        break;
+                    case 3:
+                        logout("write enable command\n");
+                        eeprom->writable = 1;
+                        break;
+                    }
+                } else {
+                    /* Read, write or erase word. */
+                    eeprom->data = eeprom->contents[address];
+                }
+            }
+        } else if (tick < 2 + 2 + eeprom->addrbits + 16) {
+            /* Transfer 16 data bits. */
+            tick++;
+            if (command == 2) {
+                /* Read word. */
+                eedo = ((eeprom->data & 0x8000) != 0);
+            }
+            eeprom->data <<= 1;
+            eeprom->data += eedi;
+        } else {
+            logout("additional unneeded tick, not processed\n");
+        }
+    }
+    /* Save status of EEPROM. */
+    eeprom->tick = tick;
+    eeprom->eecs = eecs;
+    eeprom->eesk = eesk;
+    eeprom->eedo = eedo;
+    eeprom->address = address;
+    eeprom->command = command;
+}
+
+uint16_t nmc93cxx_eeprom_read(nmc93cxx_eeprom_t *eeprom)
+{
+    /* Return status of pin DO (0 or 1). */
+    return eeprom->eedo;
+}
+
+
+static void
+nmc93cxx_eeprom_close(void *priv)
+{
+    nmc93cxx_eeprom_t* eeprom = (nmc93cxx_eeprom_t*)priv;
+    FILE* file = nvr_fopen(eeprom->filename, "wb");
+    if (file)
+    {
+        fwrite(eeprom->contents, 2, eeprom->size, file);
+    }
+    fclose(file);
+    free(priv);
+}
+
+uint16_t *nmc93cxx_eeprom_data(nmc93cxx_eeprom_t *eeprom)
+{
+    /* Get EEPROM data array. */
+    return &eeprom->contents[0];
+}
+
+const device_t nmc93cxx_device = {
+    .name          = "National Semiconductor NMC93Cxx",
+    .internal_name = "nmc93cxx",
+    .flags         = DEVICE_EXTPARAMS,
+    .local         = 0,
+    .init_ext      = nmc93cxx_eeprom_init_params,
+    .close         = nmc93cxx_eeprom_close,
+    .reset         = NULL,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};

src/network/network.c

@@ -73,6 +73,7 @@
 #include <86box/net_pcnet.h>
 #include <86box/net_plip.h>
 #include <86box/net_wd8003.h>
+#include <86box/net_tulip.h>
 
 #ifdef _WIN32
 #    define WIN32_LEAN_AND_MEAN
@@ -116,6 +117,7 @@ static const device_t *net_cards[] = {
     &pcnet_am79c970a_device,
     &rtl8029as_device,
     &pcnet_am79c960_vlb_device,
+    &dec_tulip_device,
     NULL
 };