Make the "AddDevice" and "RemoveDevice" more robust against ABI changes

Makefile

@@ -117,7 +117,10 @@ lib:
 	@[ -d $@ ] || mkdir -p $@
 
 release:
-	@[ -d $@ ] || mkdir -p $@
+	@$(shell [ ! -d 'release' ] && mkdir -p 'release')
+
+debug:
+	@$(shell [ ! -d 'debug' ] && mkdir -p 'debug')
 
 lib/libcontentredirection.a :$(SOURCES) $(INCLUDES) | lib release
 	@$(MAKE) BUILD=release OUTPUT=$(CURDIR)/$@ \

include/content_redirection/defines.h

@@ -0,0 +1,240 @@
+#pragma once
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define CONTENT_REDIRECTION_DEVICE_MAGIC   0x43524456 // "CRDV"
+#define CONTENT_REDIRECTION_DEVICE_VERSION 1
+
+typedef struct {
+    uint32_t dev;
+    uint32_t ino;
+    uint32_t mode;
+    uint32_t nlink;
+    uint32_t uid;
+    uint32_t gid;
+    uint32_t rdev;
+    int64_t size;
+    int64_t atime;
+    int64_t mtime;
+    int64_t ctime;
+    int64_t blksize;
+    int64_t blocks;
+} CR_Stat;
+
+typedef struct {
+    uint64_t bsize;
+    uint64_t frsize;
+    uint64_t blocks;
+    uint64_t bfree;
+    uint64_t bavail;
+    uint64_t files;
+    uint64_t ffree;
+    uint64_t favail;
+    uint64_t fsid;
+    uint64_t flag;
+    uint64_t namemax;
+} CR_Statvfs;
+
+typedef struct {
+    int64_t tv_sec;
+    int64_t tv_usec;
+} CR_Timeval;
+
+/**
+ * @brief ABI-safe representation of a devoptab_t device.
+ * * This structure bridges native devoptab implementations across the
+ * module boundary. It removes newlib-specific types (like struct _reent
+ * and native struct stat) in favor of standard-sized equivalents.
+ *
+ * * @note ERROR HANDLING: On failure, every function must return the
+ * NEGATIVE standard errno value (e.g., `return -ENOENT;`).
+ */
+typedef struct ContentRedirectionDeviceABI {
+    uint32_t magic;   /**< Identifier magic number (CONTENT_REDIRECTION_DEVICE_MAGIC) */
+    uint32_t version; /**< ABI version (CONTENT_REDIRECTION_DEVICE_VERSION) */
+    const char *name; /**< Name of the registered device (e.g., "romfs") */
+    int structSize;   /**< Size of the internal file struct */
+    int dirStateSize; /**< Size of the internal dir struct */
+    void *deviceData; /**< Context data passed into each function call */
+
+    // --- File Operations ---
+    /**
+     * @brief Opens a file.
+     * @return 0 or a positive identifier on success, negative errno on failure.
+     */
+    int (*open)(void *deviceData, void *fileStruct, const char *path, int flags, uint32_t mode);
+
+    /**
+     * @brief Closes an open file.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*close)(void *deviceData, void *fd);
+
+    /**
+     * @brief Writes data to an open file.
+     * @return Number of bytes written on success, negative errno on failure.
+     */
+    ssize_t (*write)(void *deviceData, void *fd, const char *ptr, size_t len);
+
+    /**
+     * @brief Reads data from an open file.
+     * @return Number of bytes read on success, 0 on EOF, negative errno on failure.
+     */
+    ssize_t (*read)(void *deviceData, void *fd, char *ptr, size_t len);
+
+    /**
+     * @brief Repositions the file offset.
+     * @return The new offset from the beginning of the file, negative errno on failure.
+     */
+    int64_t (*seek)(void *deviceData, void *fd, int64_t pos, int dir);
+
+    /**
+     * @brief Retrieves information about an open file descriptor.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*fstat)(void *deviceData, void *fd, CR_Stat *st);
+
+    /**
+     * @brief Retrieves information about a file by its path.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*stat)(void *deviceData, const char *file, CR_Stat *st);
+
+    /**
+     * @brief Creates a hard link to an existing file.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*link)(void *deviceData, const char *existing, const char *newLink);
+
+    /**
+     * @brief Deletes a name and possibly the file it refers to.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*unlink)(void *deviceData, const char *name);
+
+    /**
+     * @brief Changes the current working directory.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*chdir)(void *deviceData, const char *name);
+
+    /**
+     * @brief Renames a file or directory.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*rename)(void *deviceData, const char *oldName, const char *newName);
+
+    /**
+     * @brief Creates a new directory.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*mkdir)(void *deviceData, const char *path, uint32_t mode);
+
+    // --- Directory Operations ---
+
+    /**
+     * @brief Opens a directory stream.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*diropen)(void *deviceData, void *dirStruct, const char *path);
+
+    /**
+     * @brief Resets a directory stream to the beginning.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*dirreset)(void *deviceData, void *dirStruct);
+
+    /**
+     * @brief Reads the next entry from a directory stream.
+     * @return 0 on success, negative errno on failure (e.g., -ENOENT for end of stream).
+     */
+    int (*dirnext)(void *deviceData, void *dirStruct, char *filename, CR_Stat *filestat);
+
+    /**
+     * @brief Closes a directory stream.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*dirclose)(void *deviceData, void *dirStruct);
+
+    // --- Advanced / VFS Operations ---
+    /**
+     * @brief Retrieves filesystem statistics.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*statvfs)(void *deviceData, const char *path, CR_Statvfs *buf);
+
+    /**
+     * @brief Truncates an open file to a specified length.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*ftruncate)(void *deviceData, void *fd, int64_t len);
+
+    /**
+     * @brief Flushes file modifications to physical storage.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*fsync)(void *deviceData, void *fd);
+
+    /**
+     * @brief Changes the permissions of a file by path.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*chmod)(void *deviceData, const char *path, uint32_t mode);
+
+    /**
+     * @brief Changes the permissions of an open file.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*fchmod)(void *deviceData, void *fd, uint32_t mode);
+
+    /**
+     * @brief Removes a directory.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*rmdir)(void *deviceData, const char *name);
+
+    /**
+     * @brief Retrieves information about a file, not following symlinks.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*lstat)(void *deviceData, const char *file, CR_Stat *st);
+
+    /**
+     * @brief Changes the access and modification times of a file.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*utimes)(void *deviceData, const char *filename, const CR_Timeval times[2]);
+
+    /**
+     * @brief Retrieves configuration values for an open file descriptor.
+     * @return The requested configuration value, negative errno on failure.
+     */
+    int64_t (*fpathconf)(void *deviceData, void *fd, int name);
+
+    /**
+     * @brief Retrieves configuration values for a file by path.
+     * @return The requested configuration value, negative errno on failure.
+     */
+    int64_t (*pathconf)(void *deviceData, const char *path, int name);
+
+    /**
+     * @brief Creates a symbolic link.
+     * @return 0 on success, negative errno on failure.
+     */
+    int (*symlink)(void *deviceData, const char *target, const char *linkpath);
+
+    /**
+     * @brief Reads the value of a symbolic link.
+     * @return Number of bytes placed in buf on success, negative errno on failure.
+     */
+    ssize_t (*readlink)(void *deviceData, const char *path, char *buf, size_t bufsiz);
+} ContentRedirectionDeviceABI;
+
+#ifdef __cplusplus
+} // extern "C"
+#endif