Added MMFS support to the Master builds

src/model.c

@@ -17,6 +17,10 @@
 #include "z80.h"
 #include "6502.h"
 
+#ifdef INCLUDE_MMFS
+#include "mmc/mmc.h"
+#endif
+
 #define CFG_SECT_LEN 20
 
 fdc_type_t fdc_type;
@@ -265,6 +269,9 @@ void model_init()
     m6502_init();
 #ifndef NO_USE_TUBE
     tube_init();
+#endif
+#ifdef INCLUDE_MMFS
+    mmc_init();
 #endif
     cmos_load(models[curmodel]);
 }

src/pico/CMakeLists.txt

@@ -214,6 +214,20 @@ target_compile_definitions(pico_common INTERFACE
         #            DEBUG_SCANLINES
         )
 
+
+# ENABLE THIS TO INCLUDE MMFS SUPPORT ON THE RP2040 (currently Master Only)
+#
+# This adds a version of MMFS as ROM 8, and tweaks the config to use this
+# as the default filing system.
+#
+# Note: On the VGA Demo Board, gpio20/21 are used for the default UART,
+# and also for DAT1/2 on the SD Card. However, DAT1/2 are only used
+# if the SD Card is run in 4-bit mode. MMFS only uses 1-bit SPI mode.
+#
+# If you want to be very safe, then there are PCB links that can be cut
+# that isolate DAT1/2 on the SD card.
+set(INCLUDE_MMFS 1)
+
 # >>> ENABLE THIS TO GET USB SUPPORT ON THE RP2040 - however right now this interferes with video (actually it currently causes a panic)
 #set(USE_USB_KEYBOARD 1)
 
@@ -233,6 +247,12 @@ if (PICO_ON_DEVICE)
                 )
     endif ()
 
+    if (INCLUDE_MMFS)
+        target_compile_definitions(spock_common INTERFACE
+                INCLUDE_MMFS
+                )
+    endif ()
+
     if ("${CMAKE_BUILD_TYPE}" STREQUAL "Release")
         target_compile_options(spock_common INTERFACE "-Ofast")
     endif()
@@ -341,6 +361,7 @@ target_sources(spock_common INTERFACE
         ${CMAKE_CURRENT_LIST_DIR}/video/display.c
         ${CMAKE_CURRENT_LIST_DIR}/video/gui_stub.c
         ${CMAKE_CURRENT_LIST_DIR}/video/menu.c
+        ${CMAKE_CURRENT_LIST_DIR}/mmc/mmc.c
 )
 
 target_include_directories(spock_common INTERFACE

src/pico/mmc/mmc.c

@@ -0,0 +1,44 @@
+#include "mmc.h"
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+
+#define PIN_CLK  PICO_SD_CLK_PIN
+#define PIN_MOSI PICO_SD_CMD_PIN
+#define PIN_MISO PICO_SD_DAT0_PIN
+#define PIN_CS   22
+
+static volatile uint8_t port = 0;
+
+void mmc_init() {
+   gpio_init(PIN_CS);
+   gpio_put(PIN_CS, 0);  // Always selected
+   gpio_set_dir(PIN_CS, GPIO_OUT);
+
+   gpio_init(PIN_CLK);
+   gpio_put(PIN_CLK, 1);
+   gpio_set_dir(PIN_CLK, GPIO_OUT);
+   gpio_set_pulls(PIN_CLK, false, true);
+
+   gpio_init(PIN_MOSI);
+   gpio_put(PIN_MOSI, 1);
+   gpio_set_dir(PIN_MOSI, GPIO_OUT);
+   gpio_set_pulls(PIN_MOSI, true, false);
+
+   gpio_init(PIN_MISO);
+   gpio_set_dir(PIN_MISO, GPIO_IN);
+   gpio_set_pulls(PIN_MISO, true, false); // This pullup is crucial!
+}
+
+uint8_t mmc_read(uint16_t addr) {
+   if (gpio_get(PIN_MISO)) {
+      return port | 0x80;
+   } else {
+      return port & 0x7f;
+   }
+}
+
+void mmc_write(uint16_t addr, uint8_t val) {
+   port = val;
+   gpio_put(PIN_CLK,  port & 2);
+   gpio_put(PIN_MOSI, port & 1);
+}

src/pico/mmc/mmc.h

@@ -0,0 +1,10 @@
+#ifndef _MMC_H
+#define _MMC_H
+
+#include <inttypes.h>
+
+void mmc_init();
+uint8_t mmc_read(uint16_t addr);
+void mmc_write(uint16_t addr, uint8_t val);
+
+#endif

src/pico/roms/cmos.bin.inc

@@ -1,6 +1,14 @@
 static unsigned char cmos[] = {
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x02,
-  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc9, 0xff, 0xff, 0x12, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+// If MMFS is included, then use it as the default filesystem
+#ifdef INCLUDE_MMFS
+  0xc8,
+#else
+  0xc9,
+#endif
+                                                  0xff, 0xff, 0x12, 0x00,
   0x17, 0xca, 0x1e, 0x05, 0x00, 0x35, 0xa6, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

src/pico/roms/master_roms.txt

@@ -11,3 +11,4 @@
 !path ../../../roms
 
 mos320 = os/mos320.rom
+mmfs = mmfs/bitbang_fedc/MAMMFS.rom

src/pico/stub_allegro5/al_stub.cpp

@@ -286,6 +286,9 @@ struct {
         {"cmos", "cmos"},
         {"tube", "none"},
         {"romsetup", "master"},
+#ifdef INCLUDE_MMFS
+        { "rom08", "mmfs" },
+#endif
 //        { "rom08", "vdfs" },
 //        {"disc0", GAME_ROOT "/bs-badappl.dsd"},
 //        {"disc0", GAME_ROOT "/bs-wave-runner-v1-1.ssd"},

src/thumb_cpu/src/cpu_mem.c

@@ -34,6 +34,10 @@
 #include "hw_event_queue.h"
 #include "hardware/gpio.h"
 
+#ifdef INCLUDE_MMFS
+#include "mmc/mmc.h"
+#endif
+
 CU_REGISTER_DEBUG_PINS(hw_event, hw_reading, hw_writing)
 //CU_SELECT_DEBUG_PINS(hw_event)
 //CU_SELECT_DEBUG_PINS(hw_reading)
@@ -547,6 +551,10 @@ uint8_t hw_read(uint16_t addr) {
             case 0x90/8:
             case 0x98/8:
                 return non_master_fdc_read(addr);
+#ifdef INCLUDE_MMFS
+            case 0xdc/8:
+                return mmc_read(addr);
+#endif
 #endif
 #ifndef NO_USE_ADC
                 [0xc0/4] = master_only_adc_read,
@@ -797,6 +805,9 @@ static void (*sheila_write_funcs[])(uint16_t addr, uint8_t val) = {
         [0xd8/4] = master_only_adc_write,
         [0xdc/4] = master_only_adc_write,
 #endif
+#ifdef INCLUDE_MMFS
+        [0xdc/4] = mmc_write,
+#endif
 #ifndef NO_USE_TUBE
         [0xe0/4] = tube_host_write,
         [0xe4/4] = tube_host_write,