Implement the FLASH save type

README.md

@@ -18,6 +18,7 @@ Although still in early stages, rokuyon should be plug-and-play with any NTSC RO
 * [RCP Documentation](https://dragonminded.com/n64dev/Reality%20Coprocessor.pdf) - Nice reference for a subset of RDP functionality
 * [RDP Triangle Command Guide](https://docs.google.com/document/d/17ddEo61V0suXbSkKP5mY97QxgUnB-QfAjuBIsPiLWko) - Covers everything related to RDP triangles
 * [N64 bilinear filter (3-point)](https://www.shadertoy.com/view/Ws2fWV) - Reference implementation of the N64's texture filter
+* [dgb-n64](https://github.com/Dillonb/n64) - Provides details of the FLASH interface, since it isn't documented
 * Hardware tests - I'll probably be testing things myself as I go along
 
 ### Other Links

src/desktop/save_dialog.cpp

@@ -25,14 +25,16 @@ enum SaveEvent
  SELECT_0 = 1,
  SELECT_1,
  SELECT_2,
- SELECT_3
+ SELECT_3,
+ SELECT_4
 };
 
 wxBEGIN_EVENT_TABLE(SaveDialog, wxDialog)
 EVT_RADIOBUTTON(SELECT_0, SaveDialog::select0)
 EVT_RADIOBUTTON(SELECT_1, SaveDialog::select1)
 EVT_RADIOBUTTON(SELECT_2, SaveDialog::select2)
 EVT_RADIOBUTTON(SELECT_3, SaveDialog::select3)
+EVT_RADIOBUTTON(SELECT_4, SaveDialog::select4)
 EVT_BUTTON(wxID_OK, SaveDialog::confirm)
 wxEND_EVENT_TABLE()
 
@@ -41,10 +43,11 @@ uint32_t SaveDialog::selectToSize(uint32_t select)
  // Convert a save selection to a size
  switch (select)
  {
- case 1: return 0x8000; // SRAM 32KB
- case 2: return 0x0200; // EEPROM 0.5KB
- case 3: return 0x0800; // EEPROM 8KB
- default: return 0x0000; // None
+ case 1: return 0x00200; // EEPROM 0.5KB
+ case 2: return 0x00800; // EEPROM 8KB
+ case 3: return 0x08000; // SRAM 32KB
+ case 4: return 0x20000; // FLASH 128KB
+ default: return 0x00000; // None
  }
 }
 
@@ -53,10 +56,11 @@ uint32_t SaveDialog::sizeToSelect(uint32_t size)
  // Convert a save size to a selection
  switch (size)
  {
- case 0x8000: return 1; // SRAM 32KB
- case 0x0200: return 2; // EEPROM 0.5KB
- case 0x0800: return 3; // EEPROM 8KB
- default: return 0; // None
+ case 0x00200: return 1; // EEPROM 0.5KB
+ case 0x00800: return 2; // EEPROM 8KB
+ case 0x08000: return 3; // SRAM 32KB
+ case 0x20000: return 4; // FLASH 128KB
+ default: return 0; // None
  }
 }
 
@@ -71,13 +75,15 @@ SaveDialog::SaveDialog(std::string &lastPath): lastPath(lastPath),
  // Create left and right columns for the radio buttons
  wxBoxSizer *leftRadio = new wxBoxSizer(wxVERTICAL);
  wxBoxSizer *rightRadio = new wxBoxSizer(wxVERTICAL);
- wxRadioButton *buttons[4];
+ wxRadioButton *buttons[5];
 
  // Set up radio buttons for the save types
  leftRadio->Add(buttons[0] = new wxRadioButton(this, SELECT_0, "None"), 1);
- leftRadio->Add(buttons[1] = new wxRadioButton(this, SELECT_1, "SRAM 32KB"), 1);
- rightRadio->Add(buttons[2] = new wxRadioButton(this, SELECT_2, "EEPROM 0.5KB"), 1);
- rightRadio->Add(buttons[3] = new wxRadioButton(this, SELECT_3, "EEPROM 2KB"), 1);
+ leftRadio->Add(buttons[1] = new wxRadioButton(this, SELECT_1, "EEPROM 0.5KB"), 1);
+ leftRadio->Add(buttons[2] = new wxRadioButton(this, SELECT_2, "EEPROM 2KB"), 1);
+ rightRadio->Add(buttons[3] = new wxRadioButton(this, SELECT_3, "SRAM 32KB"), 1);
+ rightRadio->Add(buttons[4] = new wxRadioButton(this, SELECT_4, "FLASH 128KB"), 1);
+ rightRadio->Add(new wxStaticText(this, wxID_ANY, ""), 1);
 
  // Select the current save type by default
  selection = sizeToSelect(Core::saveSize);
@@ -134,6 +140,12 @@ void SaveDialog::select3(wxCommandEvent &event)
  selection = 3;
 }
 
+void SaveDialog::select4(wxCommandEvent &event)
+{
+ // Select save type 4
+ selection = 4;
+}
+
 void SaveDialog::confirm(wxCommandEvent &event)
 {
  // Ask for confirmation before doing anything because accidents could be bad!

src/desktop/save_dialog.h

@@ -39,6 +39,7 @@ class SaveDialog: public wxDialog
  void select1(wxCommandEvent &event);
  void select2(wxCommandEvent &event);
  void select3(wxCommandEvent &event);
+ void select4(wxCommandEvent &event);
  void confirm(wxCommandEvent &event);
 
  wxDECLARE_EVENT_TABLE();

src/memory.cpp

@@ -34,6 +34,15 @@
 #include "si.h"
 #include "vi.h"
 
+enum FlashState
+{
+ FLASH_NONE = 0,
+ FLASH_STATUS,
+ FLASH_READ,
+ FLASH_WRITE,
+ FLASH_ERASE
+};
+
 struct TLBEntry
 {
  uint32_t entryLo0;
@@ -47,13 +56,24 @@ namespace Memory
  uint8_t rdram[0x400000]; // 4MB RDRAM
  uint8_t rspMem[0x2000]; // 4KB RSP DMEM + 4KB RSP IMEM
  TLBEntry entries[32];
+
+ uint8_t writeBuf[0x80];
+ uint32_t writeOfs;
+ uint32_t eraseOfs;
+ FlashState state;
+
+ void writeFlash(uint32_t value);
 }
 
 void Memory::reset()
 {
- // Clear RDRAM and RSP DMEM/IMEM
- memset(rdram,  0, sizeof(rdram));
+ // Reset memory to its initial state
+ memset(rdram, 0, sizeof(rdram));
  memset(rspMem, 0, sizeof(rspMem));
+ memset(writeBuf, 0, sizeof(writeBuf));
+ writeOfs = 0;
+ eraseOfs = 0;
+ state = FLASH_NONE;
 
  // Map TLB entries to inaccessible locations
  for (int i = 0; i < 32; i++)
@@ -142,6 +162,11 @@ template <typename T> T Memory::read(uint32_t address)
  // Get a pointer to data in cart SRAM, if it exists
  data = &Core::save[pAddr & 0x7FFF];
  }
+ else if (pAddr >= 0x8000000 && pAddr < 0x8020000 && state == FLASH_READ)
+ {
+ // Get a pointer to data in cart FLASH, if it's readable
+ data = &Core::save[address & 0x1FFFF];
+ }
  else if (pAddr >= 0x10000000 && pAddr < 0x10000000 + std::min(Core::romSize, 0xFC00000U))
  {
  // Get a pointer to data in cart ROM
@@ -281,6 +306,11 @@ template <typename T> void Memory::write(uint32_t address, T value)
  Core::writeSave((pAddr + i) & 0x7FFF, value >> ((sizeof(T) - 1 - i) * 8));
  return;
  }
+ else if (pAddr >= 0x8000000 && pAddr < 0x8000080 && state == FLASH_WRITE)
+ {
+ // Get a pointer to data in the FLASH write buffer, if it's writable
+ data = &writeBuf[address & 0x7F];
+ }
  else if (pAddr >= 0x1FC007C0 && pAddr < 0x1FC00800)
  {
  // Get a pointer to data in PIF ROM/RAM
@@ -314,6 +344,11 @@ template <typename T> void Memory::write(uint32_t address, T value)
  // Write a value to an RDP register
  return RDP::write((pAddr & 0x1F) >> 2, value);
  }
+ else if (pAddr == 0x8010000 && Core::saveSize == 0x20000)
+ {
+ // Write a value to the FLASH register
+ return writeFlash(value);
+ }
  else
  {
  // Write a value to a group of registers
@@ -337,3 +372,64 @@ template <typename T> void Memory::write(uint32_t address, T value)
 
  LOG_WARN("Unknown memory write: 0x%X\n", address);
 }
+
+void Memory::writeFlash(uint32_t value)
+{
+ // Handle a FLASH register write based on the command byte
+ switch (uint8_t command = value >> 24)
+ {
+ case 0xD2: // Execute
+ switch (state)
+ {
+ case FLASH_WRITE:
+ // Copy the write buffer to a save block
+ for (int i = 0; i < 0x80; i++)
+ Core::writeSave(writeOfs + i, writeBuf[i]);
+ return;
+
+ case FLASH_ERASE:
+ // Reset the contents of a save block
+ for (int i = 0; i < 0x80; i++)
+ Core::writeSave(eraseOfs + i, 0xFF);
+ return;
+
+ default:
+ LOG_WARN("Executing FLASH in invalid state: %d\n", state);
+ return;
+ }
+
+ case 0xE1: // Status
+ // Change the FLASH state to status
+ state = FLASH_STATUS;
+ return;
+
+ case 0xF0: // Read
+ // Change the FLASH state to read
+ state = FLASH_READ;
+ return;
+
+ case 0xB4: // Write
+ // Change the FLASH state to write
+ state = FLASH_WRITE;
+ return;
+
+ case 0x78: // Erase
+ // Change the FLASH state to erase
+ state = FLASH_ERASE;
+ return;
+
+ case 0x4B: // Erase Offset
+ // Set the address of the save block to erase
+ eraseOfs = (value & 0xFFFF) << 7;
+ return;
+
+ case 0xA5: // Write Offset
+ // Set the address of the save block to write
+ writeOfs = (value & 0xFFFF) << 7;
+ return;
+
+ default:
+ LOG_CRIT("Unknown FLASH command: 0x%02X\n", command);
+ return;
+ }
+}

src/rsp_cp2.cpp

@@ -22,6 +22,7 @@
 
 #include "rsp_cp2.h"
 #include "log.h"
+#include "rsp.h"
 
 namespace RSP_CP2
 {

src/switch/main.cpp

@@ -219,15 +219,17 @@ bool saveTypeMenu()
  ListItem("None"),
  ListItem("EEPROM 0.5KB"),
  ListItem("EEPROM 2KB"),
- ListItem("SRAM 32KB")
+ ListItem("SRAM 32KB"),
+ ListItem("FLASH 128KB")
  };
 
  // Select the current save type by default
  switch (Core::saveSize)
  {
- case 0x0200: index = 1; break; // EEPROM 0.5KB
- case 0x0800: index = 2; break; // EEPROM 8KB
- case 0x8000: index = 3; break; // SRAM 32KB
+ case 0x00200: index = 1; break; // EEPROM 0.5KB
+ case 0x00800: index = 2; break; // EEPROM 8KB
+ case 0x08000: index = 3; break; // SRAM 32KB
+ case 0x20000: index = 4; break; // FLASH 128KB
  }
 
  // Create the save type menu
@@ -245,10 +247,11 @@ bool saveTypeMenu()
  // On confirmation, change the save type
  switch (index)
  {
- case 0: Core::resizeSave(0x0000); break; // None
- case 1: Core::resizeSave(0x0200); break; // EEPROM 0.5KB
- case 2: Core::resizeSave(0x0800); break; // EEPROM 8KB
- case 3: Core::resizeSave(0x8000); break; // SRAM 32KB
+ case 0: Core::resizeSave(0x00000); break; // None
+ case 1: Core::resizeSave(0x00200); break; // EEPROM 0.5KB
+ case 2: Core::resizeSave(0x00800); break; // EEPROM 8KB
+ case 3: Core::resizeSave(0x08000); break; // SRAM 32KB
+ case 4: Core::resizeSave(0x20000); break; // FLASH 128KB
  }
 
  // Restart the emulator