From 3c3a49195f248192fae90b13a939c38cd7b5d1c1 Mon Sep 17 00:00:00 2001
From: Will Stafford <willstafford@me.com>
Date: Tue, 16 Apr 2024 16:32:19 -0400
Subject: [PATCH 1/2] Add mgba save compatibility option.

---
 README.md                    |  3 +++
 include/arm11/config.h       |  1 +
 source/arm11/config.c        |  5 +++-
 source/arm11/open_agb_firm.c | 46 ++++++++++++++++++++++++++++++++++--
 4 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 4f7b4ca..3224123 100644
--- a/README.md
+++ b/README.md
@@ -159,6 +159,9 @@ Options for advanced users. No pun intended.
   * `11`, `13`: Flash 1m
   * `14`: SRAM 256k
   * `15`: None
+  
+`bool mgbaSaveCompat` - Look for and place romName.sav and romName.ini in the ROM directory for compatibility with mbga save behavior.
+* Default: `false`
 
 ## Patches
 open_agb_firm supports automatically applying IPS and UPS patches. To use a patch, rename the patch file to match the ROM file name (without the extension).
diff --git a/include/arm11/config.h b/include/arm11/config.h
index e1d5c6a..ffa07dc 100644
--- a/include/arm11/config.h
+++ b/include/arm11/config.h
@@ -52,6 +52,7 @@ typedef struct
 	// [advanced]
 	bool saveOverride;
 	u16 defaultSave;
+	bool mgbaSaveCompat;
 } OafConfig;
 //static_assert(sizeof(OafConfig) == 76, "nope");
 
diff --git a/source/arm11/config.c b/source/arm11/config.c
index c54e431..ea0135d 100644
--- a/source/arm11/config.c
+++ b/source/arm11/config.c
@@ -43,7 +43,8 @@
                         "volume=127\n\n"          \
                         "[advanced]\n"            \
                         "saveOverride=false\n"    \
-                        "defaultSave=14"
+                        "defaultSave=14\n"        \
+						"mgbaSaveCompat=false"
 
 
 
@@ -142,6 +143,8 @@ static int cfgIniCallback(void* user, const char* section, const char* name, con
 			config->saveOverride = (strcmp(value, "false") == 0 ? false : true);
 		if(strcmp(name, "defaultSave") == 0)
 			config->defaultSave = (u16)strtoul(value, NULL, 10);
+		if(strcmp(name, "mgbaSaveCompat") == 0)
+			config->mgbaSaveCompat = (strcmp(value, "false") == 0 ? false : true);
 	}
 	else return 0; // Error.
 
diff --git a/source/arm11/open_agb_firm.c b/source/arm11/open_agb_firm.c
index 02b3e45..bc872dc 100644
--- a/source/arm11/open_agb_firm.c
+++ b/source/arm11/open_agb_firm.c
@@ -89,7 +89,8 @@ static OafConfig g_oafConfig =
 
 	// [advanced]
 	false, // saveOverride
-	14     // defaultSave
+	14,    // defaultSave
+	false,  // mgbaSaveCompat
 };
 static KHandle g_frameReadyEvent = 0;
 
@@ -362,6 +363,27 @@ static Result showFileBrowser(char romAndSavePath[512])
 	return res;
 }
 
+static int getBasePathEnd(char path[512])
+{
+	// Returns the index of the final "/"
+	// Returns -1 on error or not found.
+	int retval = -1;
+	for (int i = 0; i < 512; i++)
+	{
+		char curChar = path[i];
+		if (curChar == '\0')
+		{
+			break;
+		}
+
+		if (curChar == '/')
+		{
+			retval = i;
+		}
+	}
+	return retval;
+}
+
 static void rom2GameCfgPath(char romPath[512])
 {
 	// Extract the file name and change the extension.
@@ -370,11 +392,31 @@ static void rom2GameCfgPath(char romPath[512])
 	safeStrcpy(tmpIniFileName, strrchr(romPath, '/') + 1, 256 - 2);
 	strcpy(tmpIniFileName + strlen(tmpIniFileName) - 4, ".ini");
 
+	// Support swapping ini/save to be in rom directory
+	char newSaveDir[512];
+	strcpy(newSaveDir, OAF_SAVE_DIR "/");
+
+	if (g_oafConfig.mgbaSaveCompat)
+	{
+		// Get rom basepath end
+		int baseEndIdx = getBasePathEnd(romPath);
+
+		// Safety check, baseEndIdx < 511 and > 0
+		// On error or OoB, it will revert to original behavior
+		if (baseEndIdx < 511 && baseEndIdx > 0)
+		{
+			// Replace the character after the trailing slash with null term
+			safeStrcpy(newSaveDir, romPath, 512);
+			newSaveDir[baseEndIdx + 1] = '\0';
+		}
+	}
+
 	// Construct the new path.
-	strcpy(romPath, OAF_SAVE_DIR "/");
+	strcpy(romPath, newSaveDir);
 	strcat(romPath, tmpIniFileName);
 }
 
+
 static void gameCfg2SavePath(char cfgPath[512], const u8 saveSlot)
 {
 	if(saveSlot > 9)

From 89ea45016c114706aab322c660056c1be68aad2d Mon Sep 17 00:00:00 2001
From: Will Stafford <willstafford@me.com>
Date: Tue, 16 Apr 2024 16:45:04 -0400
Subject: [PATCH 2/2] Fix typo in readme and spaces/tabs

---
 README.md             | 2 +-
 source/arm11/config.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 3224123..a76e750 100644
--- a/README.md
+++ b/README.md
@@ -160,7 +160,7 @@ Options for advanced users. No pun intended.
   * `14`: SRAM 256k
   * `15`: None
   
-`bool mgbaSaveCompat` - Look for and place romName.sav and romName.ini in the ROM directory for compatibility with mbga save behavior.
+`bool mgbaSaveCompat` - Look for and place romName.sav and romName.ini in the ROM directory for compatibility with mGBA save behavior.
 * Default: `false`
 
 ## Patches
diff --git a/source/arm11/config.c b/source/arm11/config.c
index ea0135d..b888739 100644
--- a/source/arm11/config.c
+++ b/source/arm11/config.c
@@ -44,7 +44,7 @@
                         "[advanced]\n"            \
                         "saveOverride=false\n"    \
                         "defaultSave=14\n"        \
-						"mgbaSaveCompat=false"
+                        "mgbaSaveCompat=false"