automate "full BIOS boot" based on BIOS checksums

Author: Arisotura

src/Args.h

@@ -135,7 +135,6 @@ struct DSiArgs final : public NDSArgs
     /// Defaults to std::nullopt, which means no SD card.
     std::optional<FATStorage> DSiSDCard;
 
-    bool FullBIOSBoot = false;
     bool DSPHLE = false;
 };
 }

src/DSi.cpp

@@ -116,7 +116,6 @@ DSi::DSi(DSiArgs&& args, void* userdata) noexcept :
     NWRAM_B = JIT.Memory.GetNWRAM_B();
     NWRAM_C = JIT.Memory.GetNWRAM_C();
 
-    SetFullBIOSBoot(args.FullBIOSBoot);
     SetDSPHLE(args.DSPHLE);
 }
 
@@ -130,6 +129,20 @@ DSi::~DSi() noexcept
 
 void DSi::Reset()
 {
+    // determine if we can do a full BIOS boot
+    // if we have incomplete BIOS dumps, we need to manually load boot2 from NAND
+
+    u32 crc_low[2], crc_full[2];
+    crc_low[0] = CRC32(ARM9iBIOS.data(), 0x8000);
+    crc_low[1] = CRC32(ARM7iBIOS.data(), 0x8000);
+    crc_full[0] = CRC32(ARM9iBIOS.data(), 0x10000);
+    crc_full[1] = CRC32(ARM7iBIOS.data(), 0x10000);
+
+    bool bios9full = (crc_low[0] != ARM9iBIOSLowCRC32) || (crc_full[0] == ARM9iBIOSCRC32);
+    bool bios7full = (crc_low[1] != ARM7iBIOSLowCRC32) || (crc_full[1] == ARM7iBIOSCRC32);
+    FullBIOSBoot = bios9full && bios7full;
+    Log(LogLevel::Debug, "DSi: full BIOS boot = %d\n", FullBIOSBoot);
+
     //ARM9.CP15Write(0x910, 0x0D00000A);
     //ARM9.CP15Write(0x911, 0x00000020);
     //ARM9.CP15Write(0x100, ARM9.CP15Read(0x100) | 0x00050000);
@@ -165,6 +178,7 @@ void DSi::Reset()
         SCFG_BIOS = 0x0101;
         ARM7BIOSProt = 0x20;
     }
+
     SCFG_Clock9 = 0x0187; // CHECKME
     SCFG_Clock7 = 0x0187;
     SCFG_EXT[0] = 0x8307F100;
@@ -739,6 +753,7 @@ void DSi::SoftReset()
     {
         SCFG_BIOS = 0x0101;
     }
+
     SCFG_Clock9 = 0x0187; // CHECKME
     SCFG_Clock7 = 0x0187;
     SCFG_EXT[0] = 0x8307F100;

src/DSi.h

@@ -183,12 +183,11 @@ class DSi final : public NDS
     u8 GPIO_IE;
     u8 GPIO_WiFi;
 
-    bool GetFullBIOSBoot() const noexcept { return FullBIOSBoot; }
-    void SetFullBIOSBoot(bool full) noexcept { FullBIOSBoot = full; }
-
     void SetDSPHLE(bool hle);
+
 private:
     bool FullBIOSBoot;
+
     void Set_SCFG_Clock9(u16 val);
     void Set_SCFG_MC(u32 val);
     void DecryptModcryptArea(u32 offset, u32 size, const u8* iv);

src/MemConstants.h

@@ -32,8 +32,17 @@ constexpr u32 ARM7BIOSSize = 0x4000;
 constexpr u32 DSiBIOSSize = 0x10000;
 constexpr u32 ITCMPhysicalSize = 0x8000;
 constexpr u32 DTCMPhysicalSize = 0x4000;
+
 constexpr u32 ARM7BIOSCRC32 = 0x1280f0d5;
 constexpr u32 ARM9BIOSCRC32 = 0x2ab23573;
+
+// CRC's for the low 32K BIOS regions
+constexpr u32 ARM7iBIOSLowCRC32 = 0x5434691D;
+constexpr u32 ARM9iBIOSLowCRC32 = 0x11E7C1EA;
+
+// CRC's for the full BIOS
+constexpr u32 ARM7iBIOSCRC32 = 0x4316CC42;
+constexpr u32 ARM9iBIOSCRC32 = 0xBAE84F6C;
 }
 
 #endif // MELONDS_MEMCONSTANTS_H

src/frontend/qt_sdl/Config.cpp

@@ -316,8 +316,6 @@ LegacyEntry LegacyFile[] =
     {"DSiBatteryLevel",    0, "DSi.Battery.Level", true},
     {"DSiBatteryCharging", 1, "DSi.Battery.Charging", true},
 
-    {"DSiFullBIOSBoot", 1, "DSi.FullBIOSBoot", true},
-
 #ifdef GDBSTUB_ENABLED
     {"GdbEnabled", 1, "Gdb.Enabled", false},
     {"GdbPortARM7", 0, "Gdb.ARM7.Port", true},

src/frontend/qt_sdl/EmuInstance.cpp

@@ -921,15 +921,6 @@ std::unique_ptr<DSiBIOSImage> EmuInstance::loadDSiARM9BIOS() noexcept
         FileRead(bios->data(), bios->size(), 1, f);
         CloseFile(f);
 
-        if (!globalCfg.GetBool("DSi.FullBIOSBoot"))
-        {
-            // herp
-            *(u32*)bios->data() = 0xEAFFFFFE; // overwrites the reset vector
-
-            // TODO!!!!
-            // hax the upper 32K out of the goddamn DSi
-            // done that :)  -pcy
-        }
         Log(Info, "ARM9i BIOS loaded from %s\n", path.c_str());
         return bios;
     }
@@ -948,15 +939,6 @@ std::unique_ptr<DSiBIOSImage> EmuInstance::loadDSiARM7BIOS() noexcept
         FileRead(bios->data(), bios->size(), 1, f);
         CloseFile(f);
 
-        if (!globalCfg.GetBool("DSi.FullBIOSBoot"))
-        {
-            // herp
-            *(u32*)bios->data() = 0xEAFFFFFE; // overwrites the reset vector
-
-            // TODO!!!!
-            // hax the upper 32K out of the goddamn DSi
-            // done that :)  -pcy
-        }
         Log(Info, "ARM7i BIOS loaded from %s\n", path.c_str());
         return bios;
     }
@@ -1348,7 +1330,6 @@ bool EmuInstance::updateConsole() noexcept
                 std::move(arm7ibios),
                 std::move(*nand),
                 std::move(sdcard),
-                globalCfg.GetBool("DSi.FullBIOSBoot"),
                 globalCfg.GetBool("DSi.DSP.HLE")
         };
 
@@ -1389,7 +1370,6 @@ bool EmuInstance::updateConsole() noexcept
             DSi* dsi = (DSi*)nds;
             DSiArgs& _dsiargs = *dsiargs;
 
-            dsi->SetFullBIOSBoot(_dsiargs.FullBIOSBoot);
             dsi->SetDSPHLE(_dsiargs.DSPHLE);
             dsi->ARM7iBIOS = *_dsiargs.ARM7iBIOS;
             dsi->ARM9iBIOS = *_dsiargs.ARM9iBIOS;

src/frontend/qt_sdl/EmuSettingsDialog.cpp

@@ -140,7 +140,6 @@ EmuSettingsDialog::EmuSettingsDialog(QWidget* parent) : QDialog(parent), ui(new
     ui->txtDLDIFolder->setText(cfg.GetQString("DLDI.FolderPath"));
     on_cbDLDIEnable_toggled();
 
-    ui->cbDSiFullBIOSBoot->setChecked(cfg.GetBool("DSi.FullBIOSBoot"));
     ui->cbDSPHLE->setChecked(cfg.GetBool("DSi.DSP.HLE"));
 
     ui->cbDSiSDEnable->setChecked(cfg.GetBool("DSi.SD.Enable"));
@@ -275,7 +274,6 @@ void EmuSettingsDialog::done(int r)
             cfg.SetQString("DSi.FirmwarePath", ui->txtDSiFirmwarePath->text());
             cfg.SetQString("DSi.NANDPath", ui->txtDSiNANDPath->text());
 
-            cfg.SetBool("DSi.FullBIOSBoot", ui->cbDSiFullBIOSBoot->isChecked());
             cfg.SetBool("DSi.DSP.HLE", ui->cbDSPHLE->isChecked());
 
             cfg.SetBool("DSi.SD.Enable", ui->cbDSiSDEnable->isChecked());