Implement file device

There is still a small amount of work to be done on the file device:
- Read file size only when requested
- Hide '.' and '..' directories
- Resize files

1 files changed, 52 insertions, 0 deletions

diff --git a/arm9/source/devices/file.h b/arm9/source/devices/file.h
new file mode 100644
index 0000000..86ca039
--- /dev/null
+++ b/arm9/source/devices/file.h
@@ -0,0 +1,52 @@
+#include <dirent.h>
+#include "../types/pathbuf.h"
+
+// #include <stdio.h>
+// #include <dirent.h>
+// #include <string.h>
+// #include <sys/stat.h>
+
+#ifndef FILE_H_
+    #define FILE_H_
+
+    typedef struct {
+        bool open;            // true if an entry is open
+        bool success;         // true if the previous operation was successful
+        bool is_dir;          // true if the open entry is a directory
+        bool child_is_dir;    // true if the selected child is a directory
+        PathBuf entry;        // write buffer for entry port
+        PathBuf action;       // write buffer for action port
+        PathBuf path;         // path of the open entry
+        PathBuf child_path;   // path of the selected child
+        u32 pointer;          // pointer in the open entry, whether dir or file
+        u32 length;           // length of the open entry, whether dir or file
+        u32 pointer_write;    // write cache for pointer
+        u32 length_write;     // write cache for length
+
+        DIR  *dir;            // structure pointing to current directory
+        FILE *file;           // opaque ID referencing the open file
+
+        FILE *tmpfile;        // to open file and keep existing file open
+        struct dirent *child; // currently-selected directory child information
+        u32 dir_i;            // index of next child to read from dir
+    } FileDevice;
+
+    void init_filesystem();
+    bool filesystem_enabled();
+
+    void fs_push_entry(FileDevice *fs, u8 byte);
+    void fs_push_action(FileDevice *fs, u8 byte);
+    bool fs_push_byte(PathBuf *buf, u8 byte);
+
+    u8 fs_read_byte(FileDevice *fs);
+    void fs_write_byte(FileDevice *fs, u8 byte);
+
+    void fs_ascend(FileDevice *fs);
+    void fs_descend(FileDevice *fs);
+
+    void fs_seek(FileDevice *fs);
+    void fs_resize(FileDevice *fs);
+
+    void fs_select_child(FileDevice *fs, u32 pointer);
+
+#endif