Refactor USB storage initialization and deinitialization

- Modularized the loading of kernel modules using an array for easier maintenance
- Added safety checks before stopping and unloading modules
- Improved error handling during USB driver startup and capacity setting
- Enhanced code readability with consistent formatting and comments
- Ensured proper file system handling to prevent corruption on memory stick

src/usb.c

@@ -2,71 +2,95 @@
 #include "oslib.h"
 #include "usb.h"
 
-///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// Globals:
-///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Global variable to store module IDs
 SceUID modules[8];
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Private functions
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-void oslStopUnloadModule(SceUID modID){
-    int status = 0;
-    sceKernelStopModule(modID, 0, NULL, &status, NULL);
-    sceKernelUnloadModule(modID);
+// Helper function to stop and unload a module
+static void oslStopUnloadModule(SceUID modID) {
+    if (modID >= 0) {
+        int status = 0;
+        sceKernelStopModule(modID, 0, NULL, &status, NULL);
+        sceKernelUnloadModule(modID);
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // PUBLIC FUNCTIONS
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-int oslInitUsbStorage()		{
-	u32 retVal = 0;
-
-    //start necessary drivers
-	modules[0] = pspSdkLoadStartModule("flash0:/kd/chkreg.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[1] = pspSdkLoadStartModule("flash0:/kd/npdrm.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[2] = pspSdkLoadStartModule("flash0:/kd/semawm.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[3] = pspSdkLoadStartModule("flash0:/kd/usbstor.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[4] = pspSdkLoadStartModule("flash0:/kd/usbstormgr.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[5] = pspSdkLoadStartModule("flash0:/kd/usbstorms.prx", PSP_MEMORY_PARTITION_KERNEL);
-    modules[6] = pspSdkLoadStartModule("flash0:/kd/usbstorboot.prx", PSP_MEMORY_PARTITION_KERNEL);
-	modules[7] = pspSdkLoadStartModule("flash0:/kd/usbdevice.prx", PSP_MEMORY_PARTITION_KERNEL); 
-
-    //setup USB drivers
+int oslInitUsbStorage() {
+    u32 retVal = 0;
+
+    // Load and start necessary kernel modules
+    const char* modulePaths[] = {
+        "flash0:/kd/chkreg.prx",
+        "flash0:/kd/npdrm.prx",
+        "flash0:/kd/semawm.prx",
+        "flash0:/kd/usbstor.prx",
+        "flash0:/kd/usbstormgr.prx",
+        "flash0:/kd/usbstorms.prx",
+        "flash0:/kd/usbstorboot.prx",
+        "flash0:/kd/usbdevice.prx"
+    };
+
+    for (int i = 0; i < 8; i++) {
+        modules[i] = pspSdkLoadStartModule(modulePaths[i], PSP_MEMORY_PARTITION_KERNEL);
+        if (modules[i] < 0) {
+            return -1; // Error loading module
+        }
+    }
+
+    // Start USB bus driver
     retVal = sceUsbStart(PSP_USBBUS_DRIVERNAME, 0, 0);
-    if (retVal != 0)
-		return -6;
+    if (retVal != 0) {
+        return -6; // Error starting USB bus driver
+    }
 
+    // Start USB storage driver
     retVal = sceUsbStart(PSP_USBSTOR_DRIVERNAME, 0, 0);
-    if (retVal != 0)
-		return -7;
+    if (retVal != 0) {
+        return -7; // Error starting USB storage driver
+    }
 
+    // Set the USB storage capacity (e.g., 8 MB)
     retVal = sceUsbstorBootSetCapacity(0x800000);
-    if (retVal != 0)
-		return -8;
+    if (retVal != 0) {
+        return -8; // Error setting USB storage capacity
+    }
 
     return 0;
 }
 
-int oslStartUsbStorage()		{
-    return sceUsbActivate(0x1c8);
+int oslStartUsbStorage() {
+    return sceUsbActivate(0x1c8); // 0x1c8 is the USB PID for storage
 }
 
-int oslStopUsbStorage()		{
-    int retVal = sceUsbDeactivate(0x1c8);
-    sceIoDevctl("fatms0:", 0x0240D81E, NULL, 0, NULL, 0 ); //Avoid corrupted files
-	return retVal;
+int oslStopUsbStorage() {
+    int retVal = sceUsbDeactivate(0x1c8); // Deactivate USB storage
+
+    // Send IOCTL to prevent file corruption on the memory stick
+    sceIoDevctl("fatms0:", 0x0240D81E, NULL, 0, NULL, 0);
+
+    return retVal;
 }
 
-int oslDeinitUsbStorage()			{
-    int i;
-	unsigned long state = oslGetUsbState();
-    if (state & PSP_USB_ACTIVATED)
+int oslDeinitUsbStorage() {
+    // Stop USB storage if it is still active
+    unsigned long state = oslGetUsbState();
+    if (state & PSP_USB_ACTIVATED) {
         oslStopUsbStorage();
+    }
+
+    // Stop USB drivers
     sceUsbStop(PSP_USBSTOR_DRIVERNAME, 0, 0);
     sceUsbStop(PSP_USBBUS_DRIVERNAME, 0, 0);
-    for (i=7; i>=0; i--)
-		if (modules[i] >= 0)
-			oslStopUnloadModule(modules[i]);
+
+    // Stop and unload all loaded modules in reverse order
+    for (int i = 7; i >= 0; i--) {
+        oslStopUnloadModule(modules[i]);
+    }
+
     return 0;
 }