Merge pull request #1 from pret/master

Update fork to match main fork.

1 files changed, 297 insertions, 261 deletions

diff --git a/src/save.c b/src/save.c
index 1f527bbc0..570210fb0 100644
--- a/src/save.c
+++ b/src/save.c
@@ -1,59 +1,86 @@
 #include "global.h"
-#include "save.h"
-#include "asm.h"
 #include "gba/gba.h"
+#include "gba/flash_internal.h"
+#include "save.h"
 #include "load_save.h"
 #include "rom4.h"
-#include "gba/flash_internal.h"
-
-extern struct SaveSection unk_2000000;
+#include "save_failed_screen.h"
+
+#define GETVALIDSTATUSBITFIELD ((1 << ARRAY_COUNT(gSaveSectionLocations)) - 1)
+#define GETCHUNKSIZE(chunk, n) ((sizeof(chunk) - (0xF80 * (n - 1))) >= 0xF80 ? 0xF80 : (sizeof(chunk) - (0xF80 * (n - 1))))
+#define GETBLOCKOFFSET(n) (0xF80 * (n - 1))
+#define TOTALNUMSECTORS ((ARRAY_COUNT(gSaveSectionLocations) * 2) + (ARRAY_COUNT(gHallOfFameSaveSectionLocations) * 2)) // there are 2 slots, so double each array count and get the sum.
+
+extern u32 gLastSaveSectorStatus; // used but in an unferenced function, so unused
+extern u16 gLastWrittenSector;
+extern u32 gLastSaveCounter;
+extern u16 gLastKnownGoodSector;
+extern u32 gDamagedSaveSectors;
+extern u32 gSaveCounter;
+extern struct SaveSection unk_2000000; // slow save RAM
+extern struct SaveSection *gFastSaveSection; // the pointer is in fast IWRAM but may sometimes point to the slower EWRAM.
+extern u16 gUnknown_03005EB4;
+extern u16 gSaveFileStatus;
+extern u32 gGameContinueCallback;
 
-extern u32 gUnknown_02039284;
+extern struct PokemonStorage gPokemonStorage;
+extern struct HallOfFame gHallOfFame;
 
-extern u32 gUnknown_3004820;
+const struct SaveSectionLocation gSaveSectionLocations[] =
+{
+    {((u8 *) &gSaveBlock2) + GETBLOCKOFFSET(1), GETCHUNKSIZE(gSaveBlock2, 1)},
+    {((u8 *) &gSaveBlock1) + GETBLOCKOFFSET(1), GETCHUNKSIZE(gSaveBlock1, 1)},
+    {((u8 *) &gSaveBlock1) + GETBLOCKOFFSET(2), GETCHUNKSIZE(gSaveBlock1, 2)},
+    {((u8 *) &gSaveBlock1) + GETBLOCKOFFSET(3), GETCHUNKSIZE(gSaveBlock1, 3)},
+    {((u8 *) &gSaveBlock1) + GETBLOCKOFFSET(4), GETCHUNKSIZE(gSaveBlock1, 4)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(1), GETCHUNKSIZE(gPokemonStorage, 1)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(2), GETCHUNKSIZE(gPokemonStorage, 2)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(3), GETCHUNKSIZE(gPokemonStorage, 3)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(4), GETCHUNKSIZE(gPokemonStorage, 4)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(5), GETCHUNKSIZE(gPokemonStorage, 5)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(6), GETCHUNKSIZE(gPokemonStorage, 6)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(7), GETCHUNKSIZE(gPokemonStorage, 7)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(8), GETCHUNKSIZE(gPokemonStorage, 8)},
+    {((u8 *) &gPokemonStorage) + GETBLOCKOFFSET(9), GETCHUNKSIZE(gPokemonStorage, 9)}
+};
 
-extern u16 gUnknown_03005E9C;
-extern u32 gUnknown_03005EA0;
-extern u16 gUnknown_03005EA4;
-extern u32 gUnknown_03005EA8;
-extern u32 gUnknown_03005EAC;
-extern struct SaveSection *gUnknown_03005EB0;
-extern u16 gUnknown_03005EB4;
-extern u16 gSaveFileStatus;
-extern u32 gUnknown_03005EBC;
+const struct SaveSectionLocation gHallOfFameSaveSectionLocations[] =
+{
+    {((u8 *) &gHallOfFame) + GETBLOCKOFFSET(1), GETCHUNKSIZE(struct HallOfFame, 1)}, // gHallOfFame is not a proper sym, so the struct must be used.
+    {((u8 *) &gHallOfFame) + GETBLOCKOFFSET(2), GETCHUNKSIZE(struct HallOfFame, 2)}
+};
 
-extern struct SaveSectionLocation gSaveSectionLocations[];
-extern struct SaveSectionLocation gHallOfFameSaveSectionLocations[];
-extern u8 gUnknown_08401E24[];
+const u8 gFlashSectors[] = { 0x1E, 0x1F };
 
 void ClearSaveData(void)
 {
     u16 i;
-    for (i = 0; i < 32; i++)
+
+    for (i = 0; i < NUM_SECTORS; i++)
         EraseFlashSector(i);
 }
 
-void sub_81251B8(void)
+void ResetSaveCounters(void)
 {
-    gUnknown_03005EAC = 0;
-    gUnknown_03005E9C = 0;
-    gUnknown_03005EA8 = 0;
+    gSaveCounter = 0;
+    gLastWrittenSector = 0;
+    gDamagedSaveSectors = 0;
 }
 
-bool32 sub_81251D4(u8 op, u8 bit)
+bool32 SetDamagedSectorBits(u8 op, u8 bit)
 {
     bool32 retVal = FALSE;
 
     switch (op)
     {
-    case 0:
-        gUnknown_03005EA8 |= 1 << bit;
+    case ENABLE:
+        gDamagedSaveSectors |= (1 << bit);
         break;
-    case 1:
-        gUnknown_03005EA8 &= ~(1 << bit);
+    case DISABLE:
+        gDamagedSaveSectors &= ~(1 << bit);
         break;
-    case 2:
-        if (gUnknown_03005EA8 & (1 << bit))
+    case CHECK: // unused
+        if (gDamagedSaveSectors & (1 << bit))
             retVal = TRUE;
         break;
     }
@@ -61,67 +88,70 @@ bool32 sub_81251D4(u8 op, u8 bit)
     return retVal;
 }
 
-u8 save_write_to_flash(u16 a1, struct SaveSectionLocation *a2)
+u8 save_write_to_flash(u16 a1, const struct SaveSectionLocation *location)
 {
     u32 retVal;
     u16 i;
 
-    gUnknown_03005EB0 = &unk_2000000;
+    gFastSaveSection = &unk_2000000;
 
-    if (a1 != 0xFFFF)
+    if (a1 != 0xFFFF) // for link
     {
-        retVal = sub_81252D8(a1, a2);
+        retVal = HandleWriteSector(a1, location);
     }
     else
     {
-        gUnknown_03005EA4 = gUnknown_03005E9C;
-        gUnknown_03005EA0 = gUnknown_03005EAC;
-        gUnknown_03005E9C++;
-        gUnknown_03005E9C = gUnknown_03005E9C % 14;
-        gUnknown_03005EAC++;
+        gLastKnownGoodSector = gLastWrittenSector; // backup the current written sector before attempting to write.
+        gLastSaveCounter = gSaveCounter;
+        gLastWrittenSector++;
+        gLastWrittenSector = gLastWrittenSector % ARRAY_COUNT(gSaveSectionLocations);
+        gSaveCounter++;
         retVal = 1;
-        for (i = 0; i < 14; i++)
-            sub_81252D8(i, a2);
-        if (gUnknown_03005EA8)
+
+        for (i = 0; i < ARRAY_COUNT(gSaveSectionLocations); i++)
+            HandleWriteSector(i, location);
+
+        if (gDamagedSaveSectors != 0) // skip the damaged sector.
         {
             retVal = 0xFF;
-            gUnknown_03005E9C = gUnknown_03005EA4;
-            gUnknown_03005EAC = gUnknown_03005EA0;
+            gLastWrittenSector = gLastKnownGoodSector;
+            gSaveCounter = gLastSaveCounter;
         }
     }
 
     return retVal;
 }
 
-u8 sub_81252D8(u16 a1, struct SaveSectionLocation *a2)
+u8 HandleWriteSector(u16 a1, const struct SaveSectionLocation *location)
 {
     u16 i;
     u16 sector;
     u8 *data;
     u16 size;
 
-    sector = a1 + gUnknown_03005E9C;
-    sector %= 14;
-    sector += 14 * (gUnknown_03005EAC % 2);
+    sector = a1 + gLastWrittenSector;
+    sector %= ARRAY_COUNT(gSaveSectionLocations);
+    sector += ARRAY_COUNT(gSaveSectionLocations) * (gSaveCounter % 2);
 
-    data = a2[a1].data;
-    size = a2[a1].size;
+    data = location[a1].data;
+    size = location[a1].size;
 
+    // clear save section.
     for (i = 0; i < sizeof(struct SaveSection); i++)
-        ((char *)gUnknown_03005EB0)[i] = 0;
+        ((char *)gFastSaveSection)[i] = 0;
 
-    gUnknown_03005EB0->id = a1;
-    gUnknown_03005EB0->unknown = 0x8012025;
-    gUnknown_03005EB0->counter = gUnknown_03005EAC;
+    gFastSaveSection->id = a1;
+    gFastSaveSection->security = UNKNOWN_CHECK_VALUE;
+    gFastSaveSection->counter = gSaveCounter;
 
     for (i = 0; i < size; i++)
-        gUnknown_03005EB0->data[i] = data[i];
+        gFastSaveSection->data[i] = data[i];
 
-    gUnknown_03005EB0->checksum = sub_8125C10(data, size);
-    return sub_8125440(sector, gUnknown_03005EB0->data);
+    gFastSaveSection->checksum = CalculateChecksum(data, size);
+    return TryWriteSector(sector, gFastSaveSection->data);
 }
 
-u8 sub_81253C8(u8 sector, u8 *data, u16 size)
+u8 HandleWriteSectorNBytes(u8 sector, u8 *data, u16 size)
 {
     u16 i;
     struct SaveSection *section = &unk_2000000;
@@ -129,66 +159,66 @@ u8 sub_81253C8(u8 sector, u8 *data, u16 size)
     for (i = 0; i < sizeof(struct SaveSection); i++)
         ((char *)section)[i] = 0;
 
-    section->unknown = 0x8012025;
+    section->security = UNKNOWN_CHECK_VALUE;
 
     for (i = 0; i < size; i++)
         section->data[i] = data[i];
 
-    section->id = sub_8125C10(data, size); // id instead of checksum?
-    return sub_8125440(sector, section->data);
+    section->id = CalculateChecksum(data, size); // though this appears to be incorrect, it might be some sector checksum instead of a whole save checksum and only appears to be relevent to HOF data, if used.
+    return TryWriteSector(sector, section->data);
 }
 
-u8 sub_8125440(u8 sector, u8 *data)
+u8 TryWriteSector(u8 sector, u8 *data)
 {
-    if (ProgramFlashSectorAndVerify(sector, data))
+    if (ProgramFlashSectorAndVerify(sector, data) != 0) // is damaged?
     {
-        sub_81251D4(0, sector);
+        SetDamagedSectorBits(ENABLE, sector); // set damaged sector bits.
         return 0xFF;
     }
     else
     {
-        sub_81251D4(1, sector);
+        SetDamagedSectorBits(DISABLE, sector); // unset damaged sector bits. it's safe now.
         return 1;
     }
 }
 
-u32 sub_812546C(struct SaveSectionLocation *a1)
+u32 RestoreSaveBackupVarsAndIncrement(const struct SaveSectionLocation *location) // location is unused
 {
-    gUnknown_03005EB0 = &unk_2000000;
-    gUnknown_03005EA4 = gUnknown_03005E9C;
-    gUnknown_03005EA0 = gUnknown_03005EAC;
-    gUnknown_03005E9C++;
-    gUnknown_03005E9C = gUnknown_03005E9C % 14;
-    gUnknown_03005EAC++;
+    gFastSaveSection = &unk_2000000;
+    gLastKnownGoodSector = gLastWrittenSector;
+    gLastSaveCounter = gSaveCounter;
+    gLastWrittenSector++;
+    gLastWrittenSector = gLastWrittenSector % ARRAY_COUNT(gSaveSectionLocations);
+    gSaveCounter++;
     gUnknown_03005EB4 = 0;
-    gUnknown_03005EA8 = 0;
+    gDamagedSaveSectors = 0;
     return 0;
 }
 
-u32 sub_81254C8(struct SaveSectionLocation *a1)
+u32 RestoreSaveBackupVars(const struct SaveSectionLocation *location) // only ever called once, and gSaveBlock2 is passed to this function. location is unused
 {
-    gUnknown_03005EB0 = &unk_2000000;
-    gUnknown_03005EA4 = gUnknown_03005E9C;
-    gUnknown_03005EA0 = gUnknown_03005EAC;
+    gFastSaveSection = &unk_2000000;
+    gLastKnownGoodSector = gLastWrittenSector;
+    gLastSaveCounter = gSaveCounter;
     gUnknown_03005EB4 = 0;
-    gUnknown_03005EA8 = 0;
+    gDamagedSaveSectors = 0;
     return 0;
 }
 
-u8 sub_812550C(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_812550C(u16 a1, const struct SaveSectionLocation *location)
 {
     u8 retVal;
 
     if (gUnknown_03005EB4 < a1 - 1)
     {
         retVal = 1;
-        sub_81252D8(gUnknown_03005EB4, a2);
+        HandleWriteSector(gUnknown_03005EB4, location);
         gUnknown_03005EB4++;
-        if (gUnknown_03005EA8)
+        if (gDamagedSaveSectors)
         {
             retVal = 0xFF;
-            gUnknown_03005E9C = gUnknown_03005EA4;
-            gUnknown_03005EAC = gUnknown_03005EA0;
+            gLastWrittenSector = gLastKnownGoodSector;
+            gSaveCounter = gLastSaveCounter;
         }
     }
     else
@@ -199,20 +229,22 @@ u8 sub_812550C(u16 a1, struct SaveSectionLocation *a2)
     return retVal;
 }
 
-u8 sub_812556C(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_812556C(u16 a1, const struct SaveSectionLocation *location)
 {
     u8 retVal = 1;
-    sub_81255B8(a1 - 1, a2);
-    if (gUnknown_03005EA8)
+
+    sub_81255B8(a1 - 1, location);
+
+    if (gDamagedSaveSectors)
     {
         retVal = 0xFF;
-        gUnknown_03005E9C = gUnknown_03005EA4;
-        gUnknown_03005EAC = gUnknown_03005EA0;
+        gLastWrittenSector = gLastKnownGoodSector;
+        gSaveCounter = gLastSaveCounter;
     }
     return retVal;
 }
 
-u8 sub_81255B8(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_81255B8(u16 a1, const struct SaveSectionLocation *location)
 {
     u16 i;
     u16 sector;
@@ -220,32 +252,35 @@ u8 sub_81255B8(u16 a1, struct SaveSectionLocation *a2)
     u16 size;
     u8 status;
 
-    sector = a1 + gUnknown_03005E9C;
-    sector %= 14;
-    sector += 14 * (gUnknown_03005EAC % 2);
+    sector = a1 + gLastWrittenSector;
+    sector %= ARRAY_COUNT(gSaveSectionLocations);
+    sector += ARRAY_COUNT(gSaveSectionLocations) * (gSaveCounter % 2);
 
-    data = a2[a1].data;
-    size = a2[a1].size;
+    data = location[a1].data;
+    size = location[a1].size;
 
+    // clear temp save section.
     for (i = 0; i < sizeof(struct SaveSection); i++)
-        ((char *)gUnknown_03005EB0)[i] = 0;
+        ((char *)gFastSaveSection)[i] = 0;
 
-    gUnknown_03005EB0->id = a1;
-    gUnknown_03005EB0->unknown = 0x8012025;
-    gUnknown_03005EB0->counter = gUnknown_03005EAC;
+    gFastSaveSection->id = a1;
+    gFastSaveSection->security = UNKNOWN_CHECK_VALUE;
+    gFastSaveSection->counter = gSaveCounter;
 
+    // set temp section's data.
     for (i = 0; i < size; i++)
-        gUnknown_03005EB0->data[i] = data[i];
+        gFastSaveSection->data[i] = data[i];
 
-    gUnknown_03005EB0->checksum = sub_8125C10(data, size);
+    // calculate checksum.
+    gFastSaveSection->checksum = CalculateChecksum(data, size);
 
     EraseFlashSector(sector);
 
     status = 1;
 
-    for (i = 0; i < 0xFF8; i++)
+    for (i = 0; i < sizeof(struct UnkSaveSection); i++)
     {
-        if (ProgramFlashByte(sector, i, ((u8 *)gUnknown_03005EB0)[i]))
+        if (ProgramFlashByte(sector, i, ((u8 *)gFastSaveSection)[i]))
         {
             status = 0xFF;
             break;
@@ -254,7 +289,7 @@ u8 sub_81255B8(u16 a1, struct SaveSectionLocation *a2)
 
     if (status == 0xFF)
     {
-        sub_81251D4(0, sector);
+        SetDamagedSectorBits(ENABLE, sector);
         return 0xFF;
     }
     else
@@ -263,7 +298,7 @@ u8 sub_81255B8(u16 a1, struct SaveSectionLocation *a2)
 
         for (i = 0; i < 7; i++)
         {
-            if (ProgramFlashByte(sector, 0xFF9 + i, ((u8 *)gUnknown_03005EB0)[0xFF9 + i]))
+            if (ProgramFlashByte(sector, 0xFF9 + i, ((u8 *)gFastSaveSection)[0xFF9 + i]))
             {
                 status = 0xFF;
                 break;
@@ -272,227 +307,228 @@ u8 sub_81255B8(u16 a1, struct SaveSectionLocation *a2)
 
         if (status == 0xFF)
         {
-            sub_81251D4(0, sector);
+            SetDamagedSectorBits(ENABLE, sector);
             return 0xFF;
         }
         else
         {
-            sub_81251D4(1, sector);
+            SetDamagedSectorBits(DISABLE, sector);
             return 1;
         }
     }
 }
 
-u8 sub_8125758(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_8125758(u16 a1, const struct SaveSectionLocation *location)
 {
     u16 sector;
 
-    sector = a1 + gUnknown_03005E9C - 1;
-    sector %= 14;
-    sector += 14 * (gUnknown_03005EAC % 2);
+    sector = a1 + gLastWrittenSector - 1;
+    sector %= ARRAY_COUNT(gSaveSectionLocations);
+    sector += ARRAY_COUNT(gSaveSectionLocations) * (gSaveCounter % 2);
 
-    if (ProgramFlashByte(sector, 0xFF8, ((u8 *)gUnknown_03005EB0)[0xFF8]))
+    if (ProgramFlashByte(sector, sizeof(struct UnkSaveSection), ((u8 *)gFastSaveSection)[sizeof(struct UnkSaveSection)]))
     {
-        sub_81251D4(0, sector);
-        gUnknown_03005E9C = gUnknown_03005EA4;
-        gUnknown_03005EAC = gUnknown_03005EA0;
+        // sector is damaged, so enable the bit in gDamagedSaveSectors and restore the last written sector and save counter.
+        SetDamagedSectorBits(ENABLE, sector);
+        gLastWrittenSector = gLastKnownGoodSector;
+        gSaveCounter = gLastSaveCounter;
         return 0xFF;
     }
     else
     {
-        sub_81251D4(1u, sector);
+        SetDamagedSectorBits(DISABLE, sector);
         return 1;
     }
 }
 
-u8 sub_81257F0(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_81257F0(u16 a1, const struct SaveSectionLocation *location)
 {
     u16 sector;
 
-    sector = a1 + gUnknown_03005E9C - 1;
-    sector %= 14;
-    sector += 14 * (gUnknown_03005EAC % 2);
+    sector = a1 + gLastWrittenSector - 1;
+    sector %= ARRAY_COUNT(gSaveSectionLocations);
+    sector += ARRAY_COUNT(gSaveSectionLocations) * (gSaveCounter % 2);
 
-    if (ProgramFlashByte(sector, 0xFF8, 0x25))
+    if (ProgramFlashByte(sector, sizeof(struct UnkSaveSection), 0x25))
     {
-        sub_81251D4(0, sector);
-        gUnknown_03005E9C = gUnknown_03005EA4;
-        gUnknown_03005EAC = gUnknown_03005EA0;
+        // sector is damaged, so enable the bit in gDamagedSaveSectors and restore the last written sector and save counter.
+        SetDamagedSectorBits(ENABLE, sector);
+        gLastWrittenSector = gLastKnownGoodSector;
+        gSaveCounter = gLastSaveCounter;
         return 0xFF;
     }
     else
     {
-        sub_81251D4(1u, sector);
+        SetDamagedSectorBits(DISABLE, sector);
         return 1;
     }
 }
 
-u8 sub_812587C(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_812587C(u16 a1, const struct SaveSectionLocation *location)
 {
     u8 retVal;
-    gUnknown_03005EB0 = &unk_2000000;
+    gFastSaveSection = &unk_2000000;
     if (a1 != 0xFFFF)
     {
         retVal = 0xFF;
     }
     else
     {
-        retVal = sub_8125974(a2);
-        sub_81258BC(0xFFFF, a2);
+        retVal = GetSaveValidStatus(location);
+        sub_81258BC(0xFFFF, location);
     }
 
     return retVal;
 }
 
-u8 sub_81258BC(u16 a1, struct SaveSectionLocation *a2)
+u8 sub_81258BC(u16 a1, const struct SaveSectionLocation *location)
 {
     u16 i;
     u16 checksum;
-    u16 v3 = 14 * (gUnknown_03005EAC % 2);
+    u16 v3 = ARRAY_COUNT(gSaveSectionLocations) * (gSaveCounter % 2);
     u16 id;
 
-    for (i = 0; i < 14; i++)
+    for (i = 0; i < ARRAY_COUNT(gSaveSectionLocations); i++)
     {
-        sub_8125BF8(i + v3, gUnknown_03005EB0);
-        id = gUnknown_03005EB0->id;
+        DoReadFlashWholeSection(i + v3, gFastSaveSection);
+        id = gFastSaveSection->id;
         if (id == 0)
-            gUnknown_03005E9C = i;
-        checksum = sub_8125C10(gUnknown_03005EB0->data, a2[id].size);
-        if (gUnknown_03005EB0->unknown == 0x8012025
-         && gUnknown_03005EB0->checksum == checksum)
+            gLastWrittenSector = i;
+        checksum = CalculateChecksum(gFastSaveSection->data, location[id].size);
+        if (gFastSaveSection->security == UNKNOWN_CHECK_VALUE
+         && gFastSaveSection->checksum == checksum)
         {
             u16 j;
-            for (j = 0; j < a2[id].size; j++)
-                ((u8 *)a2[id].data)[j] = gUnknown_03005EB0->data[j];
+            for (j = 0; j < location[id].size; j++)
+                ((u8 *)location[id].data)[j] = gFastSaveSection->data[j];
         }
     }
 
     return 1;
 }
 
-u8 sub_8125974(struct SaveSectionLocation *a1)
+u8 GetSaveValidStatus(const struct SaveSectionLocation *location)
 {
     u16 i;
     u16 checksum;
-    u32 v2 = 0;
-    u32 v3 = 0;
-    u32 v4;
-    bool8 v5;
-    u8 v14;
-    u8 v10;
-
-    v4 = 0;
-    v5 = FALSE;
-
-    for (i = 0; i < 14; i++)
-    {
-        sub_8125BF8(i, gUnknown_03005EB0);
-        if (gUnknown_03005EB0->unknown == 0x8012025)
+    u32 saveSlot1Counter = 0;
+    u32 saveSlot2Counter = 0;
+    u32 slotCheckField = 0;
+    bool8 securityPassed = FALSE;
+    u8 saveSlot1Status;
+    u8 saveSlot2Status;
+
+    // check save slot 1.
+    for (i = 0; i < ARRAY_COUNT(gSaveSectionLocations); i++)
+    {
+        DoReadFlashWholeSection(i, gFastSaveSection);
+        if (gFastSaveSection->security == UNKNOWN_CHECK_VALUE)
         {
-            v5 = TRUE;
-            checksum = sub_8125C10(gUnknown_03005EB0->data, a1[gUnknown_03005EB0->id].size);
-            if (gUnknown_03005EB0->checksum == checksum)
+            securityPassed = TRUE;
+            checksum = CalculateChecksum(gFastSaveSection->data, location[gFastSaveSection->id].size);
+            if (gFastSaveSection->checksum == checksum)
             {
-                v2 = gUnknown_03005EB0->counter;
-                v4 |= 1 << gUnknown_03005EB0->id;
+                saveSlot1Counter = gFastSaveSection->counter;
+                slotCheckField |= 1 << gFastSaveSection->id;
             }
         }
     }
 
-    if (v5)
+    if (securityPassed)
     {
-        if (v4 == 0x3FFF)
-            v14 = 1;
+        if (slotCheckField == GETVALIDSTATUSBITFIELD)
+            saveSlot1Status = 1;
         else
-            v14 = 255;
+            saveSlot1Status = 255;
     }
     else
     {
-        v14 = 0;
+        saveSlot1Status = 0;
     }
 
-    v4 = 0;
-    v5 = FALSE;
+    slotCheckField = 0;
+    securityPassed = FALSE;
 
-    for (i = 0; i < 14; i++)
+    // check save slot 2.
+    for (i = 0; i < ARRAY_COUNT(gSaveSectionLocations); i++)
     {
-        sub_8125BF8(i + 14, gUnknown_03005EB0);
-        if (gUnknown_03005EB0->unknown == 0x8012025)
+        DoReadFlashWholeSection(i + ARRAY_COUNT(gSaveSectionLocations), gFastSaveSection);
+        if (gFastSaveSection->security == UNKNOWN_CHECK_VALUE)
         {
-            v5 = TRUE;
-            checksum = sub_8125C10(gUnknown_03005EB0->data, a1[gUnknown_03005EB0->id].size);
-            if (gUnknown_03005EB0->checksum == checksum)
+            securityPassed = TRUE;
+            checksum = CalculateChecksum(gFastSaveSection->data, location[gFastSaveSection->id].size);
+            if (gFastSaveSection->checksum == checksum)
             {
-                v3 = gUnknown_03005EB0->counter;
-                v4 |= 1 << gUnknown_03005EB0->id;
+                saveSlot2Counter = gFastSaveSection->counter;
+                slotCheckField |= 1 << gFastSaveSection->id;
             }
         }
     }
 
-    if (v5)
+    if (securityPassed)
     {
-        if (v4 == 0x3FFF)
-            v10 = 1;
+        if (slotCheckField == GETVALIDSTATUSBITFIELD)
+            saveSlot2Status = 1;
         else
-            v10 = 255;
+            saveSlot2Status = 255;
     }
     else
     {
-        v10 = 0;
+        saveSlot2Status = 0;
     }
 
-    if (v14 == 1 && v10 == 1)
+    if (saveSlot1Status == 1 && saveSlot2Status == 1)
     {
-        if ((v2 == -1 && v3 == 0) || (v2 == 0 && v3 == -1))
+        if ((saveSlot1Counter == -1 && saveSlot2Counter == 0) || (saveSlot1Counter == 0 && saveSlot2Counter == -1))
         {
-            if ((unsigned)(v2 + 1) < (unsigned)(v3 + 1))
+            if ((unsigned)(saveSlot1Counter + 1) < (unsigned)(saveSlot2Counter + 1))
             {
-                gUnknown_03005EAC = v3;
+                gSaveCounter = saveSlot2Counter;
             }
             else
             {
-                gUnknown_03005EAC = v2;
+                gSaveCounter = saveSlot1Counter;
             }
         }
         else
         {
-            if (v2 < v3)
+            if (saveSlot1Counter < saveSlot2Counter)
             {
-                gUnknown_03005EAC = v3;
+                gSaveCounter = saveSlot2Counter;
             }
             else
             {
-                gUnknown_03005EAC = v2;
+                gSaveCounter = saveSlot1Counter;
             }
         }
         return 1;
     }
 
-    if (v14 == 1)
+    if (saveSlot1Status == 1)
     {
-        gUnknown_03005EAC = v2;
-        if (v10 == 255)
+        gSaveCounter = saveSlot1Counter;
+        if (saveSlot2Status == 255)
             return 255;
         return 1;
     }
 
-    if (v10 == 1)
+    if (saveSlot2Status == 1)
     {
-        gUnknown_03005EAC = v3;
-        if (v14 == 255)
+        gSaveCounter = saveSlot2Counter;
+        if (saveSlot1Status == 255)
             return 255;
         return 1;
     }
 
-    if (v14 == 0 && v10 == 0)
+    if (saveSlot1Status == 0 && saveSlot2Status == 0)
     {
-        gUnknown_03005EAC = 0;
-        gUnknown_03005E9C = 0;
+        gSaveCounter = 0;
+        gLastWrittenSector = 0;
         return 0;
     }
 
-    gUnknown_03005EAC = 0;
-    gUnknown_03005E9C = 0;
+    gSaveCounter = 0;
+    gLastWrittenSector = 0;
     return 2;
 }
 
@@ -500,10 +536,10 @@ u8 sub_8125B88(u8 a1, u8 *data, u16 size)
 {
     u16 i;
     struct SaveSection *section = &unk_2000000;
-    sub_8125BF8(a1, section);
-    if (section->unknown == 0x8012025)
+    DoReadFlashWholeSection(a1, section);
+    if (section->security == UNKNOWN_CHECK_VALUE)
     {
-        u16 checksum = sub_8125C10(section->data, size);
+        u16 checksum = CalculateChecksum(section->data, size);
         if (section->id == checksum)
         {
             for (i = 0; i < size; i++)
@@ -521,13 +557,13 @@ u8 sub_8125B88(u8 a1, u8 *data, u16 size)
     }
 }
 
-u8 sub_8125BF8(u8 sector, struct SaveSection *section)
+u8 DoReadFlashWholeSection(u8 sector, struct SaveSection *section)
 {
-    ReadFlash(sector, 0, section->data, 0x1000);
+    ReadFlash(sector, 0, section->data, sizeof(struct SaveSection));
     return 1;
 }
 
-u16 sub_8125C10(void *data, u16 size)
+u16 CalculateChecksum(void *data, u16 size)
 {
     u16 i;
     u32 checksum = 0;
@@ -538,39 +574,39 @@ u16 sub_8125C10(void *data, u16 size)
     return ((checksum >> 16) + checksum);
 }
 
-u8 sub_8125C3C(u8 a1)
+u8 HandleSavingData(u8 saveType)
 {
     u8 i;
-    switch (a1)
+    switch (saveType)
     {
-    case 5:
-        for (i = 28; i < 32; i++)
+    case HOF_DELETE_SAVE: // deletes HOF before overwriting HOF completely. unused
+        for (i = (ARRAY_COUNT(gSaveSectionLocations) * 2 + 0); i < TOTALNUMSECTORS; i++)
             EraseFlashSector(i);
-    case 3:
-        if (sub_8053108(10) < 999)
-            sav12_xor_increment(10);
-        for (i = 0; i < 2; i++)
-            sub_81253C8(28 + i, gHallOfFameSaveSectionLocations[i].data, gHallOfFameSaveSectionLocations[i].size);
+    case HOF_SAVE: // hall of fame.
+        if (GetGameStat(10) < 999)
+            IncrementGameStat(10);
+        for (i = 0; i < ARRAY_COUNT(gHallOfFameSaveSectionLocations); i++)
+            HandleWriteSectorNBytes((ARRAY_COUNT(gSaveSectionLocations) * 2 + 0) + i, gHallOfFameSaveSectionLocations[i].data, gHallOfFameSaveSectionLocations[i].size);
         SaveSerializedGame();
         save_write_to_flash(0xFFFF, gSaveSectionLocations);
         break;
-    case 0:
+    case NORMAL_SAVE: // normal save. also called by overwriting your own save.
     default:
         SaveSerializedGame();
         save_write_to_flash(0xFFFF, gSaveSectionLocations);
         break;
-    case 1:
+    case LINK_SAVE: // link save. updates only gSaveBlock1 and gSaveBlock2.
         SaveSerializedGame();
         for (i = 0; i < 5; i++)
             save_write_to_flash(i, gSaveSectionLocations);
         break;
-    case 2:
+    case EREADER_SAVE: // used in mossdeep "game corner" before/after battling old man e-reader trainer
         SaveSerializedGame();
         save_write_to_flash(0, gSaveSectionLocations);
         break;
-    case 4:
-        for (i = 28; i < 32; i++)
-            EraseFlashSector(i);
+    case DIFFERENT_FILE_SAVE: // there is a different file, so erase the file and overwrite it completely.
+        for (i = (ARRAY_COUNT(gSaveSectionLocations) * 2 + 0); i < TOTALNUMSECTORS; i++)
+            EraseFlashSector(i); // erase HOF.
         SaveSerializedGame();
         save_write_to_flash(0xFFFF, gSaveSectionLocations);
         break;
@@ -578,60 +614,60 @@ u8 sub_8125C3C(u8 a1)
     return 0;
 }
 
-u8 sub_8125D44(u8 a1)
+u8 TrySavingData(u8 saveType) // TrySave
 {
-    if (gUnknown_3004820 != 1)
+    if (gFlashMemoryPresent != TRUE)
         return 0xFF;
-    sub_8125C3C(a1);
-    if (!gUnknown_03005EA8)
+    HandleSavingData(saveType);
+    if (!gDamagedSaveSectors)
         return 1;
-    fullscreen_save_activate(a1);
+    DoSaveFailedScreen(saveType);
     return 0xFF;
 }
 
-u8 sub_8125D80(void)
+u8 sub_8125D80(void) // trade.s save
 {
-    if (gUnknown_3004820 != 1)
+    if (gFlashMemoryPresent != TRUE)
         return 1;
     SaveSerializedGame();
-    sub_812546C(gSaveSectionLocations);
+    RestoreSaveBackupVarsAndIncrement(gSaveSectionLocations);
     return 0;
 }
 
-bool8 sub_8125DA8(void)
+bool8 sub_8125DA8(void) // trade.s save
 {
-    u8 v0 = sub_812550C(14, gSaveSectionLocations);
-    if (gUnknown_03005EA8)
-        fullscreen_save_activate(0);
-    if (v0 == 0xFF)
+    u8 retVal = sub_812550C(ARRAY_COUNT(gSaveSectionLocations), gSaveSectionLocations);
+    if (gDamagedSaveSectors)
+        DoSaveFailedScreen(0);
+    if (retVal == 0xFF)
         return 1;
     else
         return 0;
 }
 
-u8 sub_8125DDC(void)
+u8 sub_8125DDC(void) // trade.s save
 {
-    sub_812556C(14, gSaveSectionLocations);
-    if (gUnknown_03005EA8)
-        fullscreen_save_activate(0);
+    sub_812556C(ARRAY_COUNT(gSaveSectionLocations), gSaveSectionLocations);
+    if (gDamagedSaveSectors)
+        DoSaveFailedScreen(0);
     return 0;
 }
 
-u8 sub_8125E04(void)
+u8 sub_8125E04(void) // trade.s save
 {
-    sub_8125758(14, gSaveSectionLocations);
-    if (gUnknown_03005EA8)
-        fullscreen_save_activate(0);
+    sub_8125758(ARRAY_COUNT(gSaveSectionLocations), gSaveSectionLocations);
+    if (gDamagedSaveSectors)
+        DoSaveFailedScreen(0);
     return 0;
 }
 
 u8 sub_8125E2C(void)
 {
-    if (gUnknown_3004820 != 1)
+    if (gFlashMemoryPresent != TRUE)
         return 1;
 
     SaveSerializedGame();
-    sub_81254C8(gSaveSectionLocations);
+    RestoreSaveBackupVars(gSaveSectionLocations);
     sub_812556C(gUnknown_03005EB4 + 1, gSaveSectionLocations);
     return 0;
 }
@@ -650,8 +686,8 @@ u8 sub_8125E6C(void)
         sub_81257F0(val, gSaveSectionLocations);
         retVal = 1;
     }
-    if (gUnknown_03005EA8)
-        fullscreen_save_activate(1);
+    if (gDamagedSaveSectors)
+        DoSaveFailedScreen(1);
     return retVal;
 }
 
@@ -659,7 +695,7 @@ u8 sub_8125EC8(u8 a1)
 {
     u8 result;
 
-    if (gUnknown_3004820 != 1)
+    if (gFlashMemoryPresent != TRUE)
     {
         gSaveFileStatus = 4;
         return 0xFF;
@@ -672,12 +708,12 @@ u8 sub_8125EC8(u8 a1)
         result = sub_812587C(0xFFFF, gSaveSectionLocations);
         LoadSerializedGame();
         gSaveFileStatus = result;
-        gUnknown_03005EBC = 0;
+        gGameContinueCallback = 0;
         break;
     case 3:
-        result = sub_8125B88(28, gHallOfFameSaveSectionLocations[0].data, gHallOfFameSaveSectionLocations[0].size);
+        result = sub_8125B88((ARRAY_COUNT(gSaveSectionLocations) * 2 + 0), gHallOfFameSaveSectionLocations[0].data, gHallOfFameSaveSectionLocations[0].size);
         if (result == 1)
-            result = sub_8125B88(29, gHallOfFameSaveSectionLocations[1].data, gHallOfFameSaveSectionLocations[1].size);
+            result = sub_8125B88((ARRAY_COUNT(gSaveSectionLocations) * 2 + 1), gHallOfFameSaveSectionLocations[1].data, gHallOfFameSaveSectionLocations[1].size);
         break;
     }
 
@@ -689,12 +725,12 @@ bool8 unref_sub_8125F4C(struct UnkSaveSection *a1)
     u16 i;
     char *raw = (char *)a1;
 
-    for (i = 0; i < 0x1000; i++)
+    for (i = 0; i < sizeof(struct SaveSection); i++)
         raw[i] = 0;
 
-    ReadFlash(gUnknown_08401E24[0], 0, a1->data, 4096);
+    ReadFlash(gFlashSectors[0], 0, a1->data, 4096);
 
-    if (a1->unknown != 0x8012025)
+    if (a1->security != UNKNOWN_CHECK_VALUE)
         return FALSE;
 
     return TRUE;
@@ -703,10 +739,10 @@ bool8 unref_sub_8125F4C(struct UnkSaveSection *a1)
 u8 unref_sub_8125FA0(void)
 {
     u16 i;
-    u8 v0 = sub_8125D44(0);
+    u8 v0 = TrySavingData(0);
 
     for (i = 0; i < 2; i++)
-        EraseFlashSector(gUnknown_08401E24[i]);
+        EraseFlashSector(gFlashSectors[i]);
 
     if (v0 == 255)
     {
@@ -728,25 +764,25 @@ u8 unref_sub_8125FF0(u8 *data, u16 size)
     u16 i;
     struct UnkSaveSection *section = (struct UnkSaveSection *)&unk_2000000;
 
-    for (i = 0; i < 0x1000; i++)
+    for (i = 0; i < sizeof(struct SaveSection); i++)
         ((char *)section)[i] = 0;
 
-    section->unknown = 0x8012025;
+    section->security = UNKNOWN_CHECK_VALUE;
 
     for (i = 0; i < size; i++)
         section->data[i] = data[i];
 
-    gUnknown_02039284 = ProgramFlashSectorAndVerifyNBytes(gUnknown_08401E24[0], (u8 *)section, 0x1000);
+    gLastSaveSectorStatus = ProgramFlashSectorAndVerifyNBytes(gFlashSectors[0], (u8 *)section, sizeof(struct SaveSection));
 
-    if (gUnknown_02039284)
-        return 255;
+    if (gLastSaveSectorStatus)
+        return 0xFF;
     else
         return 1;
 }
 
 u8 unref_sub_8126068(u8 sector, u8 *data, u32 size)
 {
-    if (ProgramFlashSectorAndVerify(sector, data, size))
+    if (ProgramFlashSectorAndVerify(sector, data))
         return 255;
     else
         return 1;
@@ -754,6 +790,6 @@ u8 unref_sub_8126068(u8 sector, u8 *data, u32 size)
 
 u8 unref_sub_8126080(u8 sector, u8 *data)
 {
-    ReadFlash(sector, 0, data, 0x1000);
+    ReadFlash(sector, 0, data, sizeof(struct SaveSection));
     return 1;
 }