Refactor the core's handling of firmware and BIOS images to rely less on the file system (#1826)

* Introduce firmware-related structs

* Fix some indents

* Move the generated firmware identifier to a constant

* Document the WifiAccessPoint constructors

* Add some constants

* Remove a stray comment

* Implement Firmware::UserData

* Add Firmware::Mask

* Document Firmware::Buffer

* Add a Firmware constructor that uses a FileHandle

* Set the default username in UserData

* Update the UserData checksum

* Forgot to include Platform.h

* Remove some redundant assignments in the default Firmware constructor

* const-ify CRC16

* Replace the plain Firmware buffer with a Firmware object

- Remove some functions that were reimplemented in the Firmware constructors

* Fix some crashes due to undefined behavior

* Fix the user data initialization

- Initialize both user data objects to default
- Set both user data objects to the same touch screen calibration

* Follow the DS logic in determining which user data section is current

* Remove an unneeded include

* Remove another unneeded include

* Initialize FirmwareMask in Firmware::Firmware

* Use the DEFAULT_SSID constant

* Add SPI_Firmware::InstallFirmware and SPI_Firmware::RemoveFirmware

* Move a logging call to after the file is written

* Add a SaveManager for the firmware

* Touch up the SPI_Firmware::Firmware declaration

* Move all firmware loading and customization to the frontend

* Call Platform::WriteFirmware when it's time to write the firmware back to disk

* Fix some missing stuff

* Remove the Get* functions from SPI_Firmware in favor of GetFirmware()

* Implement SPI_Firmware::DeInit in terms of RemoveFirmware

* Add Firmware::UpdateChecksums

* Fix an incorrect length

* Update all checksums in the firmware after setting touch screen calibration data

* Use the Firmware object's Position methods

* Remove register fields from the Firmware object

* Install the firmware before seeing if direct boot is necessary

* Install the firmware before calling NDS::Reset in LoadROM

* Slight cleanup in ROMManager

* Fix the default access point name

* Shorten the various getters in Firmware

* Add qualifiers for certain uses of firmware types

- GCC can get picky if -fpermissive isn't defined

* Add an InstallFirmware overload that takes a unique_ptr

* Log when firmware is added or removed

* Don't clear the firmware in SPI_Firmware::Init

- The original code didn't, it just set the pointer to nullptr

* Fix a typo

* Write back the full firmware if it's not generated

* Move the FreeBIOS to an external file

* Load wfcsettings.bin into the correct part of the generated firmware blob

* Load BIOS files in the frontend, not in the core

* Fix logging the firmware ID

* Add some utility functions

* Mark Firmware's constructors as explicit

* Remove obsolete ConfigEntry values

* Include <locale> explicitly in ROMManager

* Fix up some includes

* Add Firmware::IsBootable()

* Add a newline to a log entry

- Whoops

* Log the number of bytes written out in SaveManager

* Mark FirmwareHeader's constructor as explicit

* Clean up GenerateDefaultFirmware and LoadFirmwareFromFile

- Now they return a pair instead of two by-ref values

* Refactor SaveManager a little bit

- Manage its buffers as unique_ptrs to mitigate leaks
- Reallocate the internal buffer if SetPath is asked to reload the file (and the new length is different)

* Remove some stray parens

* Fix some firmware-related bugs I introduced

- Firmware settings are now properly saved to disk (beforehand I misunderstood when the firmware blob was written)
- Firmware is no longer overwritten by contents of wfcsettings.bin

* Slight cleanup

src/frontend/qt_sdl/SaveManager.cpp

@@ -58,11 +58,11 @@ SaveManager::~SaveManager()
         FlushSecondaryBuffer();
     }
 
-    if (SecondaryBuffer) delete[] SecondaryBuffer;
+    SecondaryBuffer = nullptr;
 
     delete SecondaryBufferLock;
 
-    if (Buffer) delete[] Buffer;
+    Buffer = nullptr;
 }
 
 std::string SaveManager::GetPath()
@@ -75,11 +75,17 @@ void SaveManager::SetPath(const std::string& path, bool reload)
     Path = path;
 
     if (reload)
-    {
-        FileHandle* f = Platform::OpenFile(Path, FileMode::Read);
-        if (f)
+    { // If we should load whatever file is at the new path...
+
+        if (FileHandle* f = Platform::OpenFile(Path, FileMode::Read))
         {
-            FileRead(Buffer, 1, Length, f);
+            if (u32 length = Platform::FileLength(f); length != Length)
+            { // If the new file is a different size, we need to re-allocate the buffer.
+                Length = length;
+                Buffer = std::make_unique<u8[]>(Length);
+            }
+
+            FileRead(Buffer.get(), 1, Length, f);
             CloseFile(f);
         }
     }
@@ -91,12 +97,10 @@ void SaveManager::RequestFlush(const u8* savedata, u32 savelen, u32 writeoffset,
 {
     if (Length != savelen)
     {
-        if (Buffer) delete[] Buffer;
-
         Length = savelen;
-        Buffer = new u8[Length];
+        Buffer = std::make_unique<u8[]>(Length);
 
-        memcpy(Buffer, savedata, Length);
+        memcpy(Buffer.get(), savedata, Length);
     }
     else
     {
@@ -127,13 +131,11 @@ void SaveManager::CheckFlush()
 
     if (SecondaryBufferLength != Length)
     {
-        if (SecondaryBuffer) delete[] SecondaryBuffer;
-
         SecondaryBufferLength = Length;
-        SecondaryBuffer = new u8[SecondaryBufferLength];
+        SecondaryBuffer = std::make_unique<u8[]>(SecondaryBufferLength);
     }
 
-    memcpy(SecondaryBuffer, Buffer, Length);
+    memcpy(SecondaryBuffer.get(), Buffer.get(), Length);
 
     FlushRequested = false;
     FlushVersion++;
@@ -172,15 +174,15 @@ void SaveManager::FlushSecondaryBuffer(u8* dst, u32 dstLength)
     SecondaryBufferLock->lock();
     if (dst)
     {
-        memcpy(dst, SecondaryBuffer, SecondaryBufferLength);
+        memcpy(dst, SecondaryBuffer.get(), SecondaryBufferLength);
     }
     else
     {
         FileHandle* f = Platform::OpenFile(Path, FileMode::Write);
         if (f)
         {
-            Log(LogLevel::Info, "SaveManager: Written\n");
-            FileWrite(SecondaryBuffer, SecondaryBufferLength, 1, f);
+            FileWrite(SecondaryBuffer.get(), SecondaryBufferLength, 1, f);
+            Log(LogLevel::Info, "SaveManager: Wrote %u bytes to %s\n", SecondaryBufferLength, Path.c_str());
             CloseFile(f);
         }
     }