From 6a1b0a474ca091f37c862b47abdbe190620363f8 Mon Sep 17 00:00:00 2001
From: fgsfds <derp.primus@gmail.com>
Date: Thu, 14 Sep 2023 21:35:05 +0200
Subject: [PATCH] port: allow specifying path to eeprom file

--eeprom-file file.bin
---
 port/include/fs.h   |  3 +++
 port/src/fs.c       | 16 ++++++++++++++--
 port/src/libultra.c | 30 +++++++++++++++++++++++++++---
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/port/include/fs.h b/port/include/fs.h
index dc299cf57..561c41456 100644
--- a/port/include/fs.h
+++ b/port/include/fs.h
@@ -10,6 +10,9 @@ s32 fsInit(void);
 
 const char *fsFullPath(const char *relPath);
 
+s32 fsPathIsAbsolute(const char *path);
+s32 fsPathIsCwdRelative(const char *path);
+
 void *fsFileLoad(const char *name, u32 *outSize);
 s32 fsFileSize(const char *name);
 
diff --git a/port/src/fs.c b/port/src/fs.c
index 79d284155..fb56a6af9 100644
--- a/port/src/fs.c
+++ b/port/src/fs.c
@@ -18,7 +18,8 @@ static char saveDir[FS_MAXPATH + 1]; // replaces $S
 static char homeDir[FS_MAXPATH + 1]; // replaces $H
 static char exeDir[FS_MAXPATH + 1];  // replaces $E
 
-static s32 fsPathIsWritable(const char *path) {
+static s32 fsPathIsWritable(const char *path)
+{
 #ifdef PLATFORM_WIN32
 	// on windows access() on directories will only check if the directory exists, so
 	char tmp[FS_MAXPATH + 1] = { 0 };
@@ -35,6 +36,17 @@ static s32 fsPathIsWritable(const char *path) {
 #endif
 }
 
+s32 fsPathIsAbsolute(const char *path)
+{
+ return (path[0] == '/' || (isalpha(path[0]) && path[1] == ':'));
+}
+
+s32 fsPathIsCwdRelative(const char *path)
+{
+	// ., .., ./, ../
+	return (path[0] == '.' && (path[1] == '.' || path[1] == '/' || path[1] == '\\' || path[1] == '\0'));
+}
+
 const char *fsFullPath(const char *relPath)
 {
 	static char pathBuf[FS_MAXPATH + 1];
@@ -59,7 +71,7 @@ const char *fsFullPath(const char *relPath)
 		}
 		// couldn't expand anything, return as is
 		return relPath;
-	} else if (!dataDir[0] || relPath[0] == '.' || relPath[0] == '/' || (isalpha(relPath[0]) && relPath[1] == ':')) {
+	} else if (!dataDir[0] || fsPathIsAbsolute(relPath) || fsPathIsCwdRelative(relPath)) {
 		// user explicitly wants working directory or this is an absolute path or we have no dataDir set up yet
 		return relPath;
 	}
diff --git a/port/src/libultra.c b/port/src/libultra.c
index aa1f7522a..08e8858cb 100644
--- a/port/src/libultra.c
+++ b/port/src/libultra.c
@@ -27,6 +27,7 @@ s32 osResetType = 0;              /* 0 = cold reset */
 s32 osViClock = VI_NTSC_CLOCK;
 
 static u8 eeprom[EEPROM_SIZE];
+static char eepromPath[FS_MAXPATH + 1];
 static s32 eepromLoaded = 0;
 
 /* Time */
@@ -252,6 +253,21 @@ s32 __osMotorAccess(OSPfs *pfs, s32 cmd)
 
 /* Eeprom */
 
+static inline void osEepromSetPath(void)
+{
+	const char *extPath = sysArgGetString("--eeprom-file");
+	if (extPath && extPath[0]) {
+		if (extPath[0] == '$' || fsPathIsAbsolute(extPath) || fsPathIsCwdRelative(extPath)) {
+			strncpy(eepromPath, extPath, FS_MAXPATH);
+		} else {
+			// just a filename, look for it in the save dir
+			snprintf(eepromPath, FS_MAXPATH, "$S/%s", extPath);
+		}
+	} else {
+		strncpy(eepromPath, EEPROM_PATH, FS_MAXPATH);
+	}
+}
+
 static inline void osEeepromLoad(const char *fname)
 {
 	if (!eepromLoaded) {
@@ -284,7 +300,11 @@ s32 osEepromProbe(OSMesgQueue *mq)
 
 s32 osEepromLongRead(OSMesgQueue *mq, u8 address, u8 *buffer, int nbytes)
 {
-	osEeepromLoad(EEPROM_PATH);
+	if (!eepromPath[0]) {
+		osEepromSetPath();
+	}
+
+	osEeepromLoad(eepromPath);
 
 	memcpy(buffer, eeprom + address * 8, nbytes);
 
@@ -293,11 +313,15 @@ s32 osEepromLongRead(OSMesgQueue *mq, u8 address, u8 *buffer, int nbytes)
 
 s32 osEepromLongWrite(OSMesgQueue *mq, u8 address, u8 *buffer, int nbytes)
 {
-	osEeepromLoad(EEPROM_PATH);
+	if (!eepromPath[0]) {
+		osEepromSetPath();
+	}
+
+	osEeepromLoad(eepromPath);
 
 	memcpy(eeprom + address * 8, buffer, nbytes);
 
-	osEeepromSave(EEPROM_PATH);
+	osEeepromSave(eepromPath);
 
 	return 0;
 }