QROFS utility script

docs/qrofs.md

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+# QROFS - Quark Read-Only File System
+
+QROFS is the FS used by Quark's ramdisk VFS
+
+ - Read-only (cannot write/delete/create/rename files)
+ - Subdirectory support
+ - File size limit: 2^32 bytes
+ - File name limit: 255 characters
+ - File name validation: ASCII only
+ - File name case sensitivity: case-sensitive
+ - Maximum files per directory: 255
+
+## At a byte level
+
+NOTE: Everything is stored in little-endian format, unless otherwise noted
+
+### QROFS directory
+
+| Bits | Description |
+|-|-|
+| 8 | Header (`0x02` for directories) |
+| 8 | Name length |
+| 8*n | The directory name itself - n is the name length |
+| 8 | Number of child nodes |
+| ? | Child nodes |
+
+### QROFS file
+
+| Bits | Description |
+|-|-|
+| 8 | Header (`0x01` for files) |
+| 8 | Name length |
+| 8*n | The file name itself - n is the name length |
+| 32 | File size |
+| 8*n | File data |

tools/qrofs-util.py

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+#!/usr/bin/env python3
+
+import sys
+import os
+import struct
+
+def create(file_name, dir_name):
+    if not os.path.exists(dir_name):
+        print(f"ERROR: {dir_name} does not exist")
+        exit(1)
+    
+    out_fd = open(file_name, "wb+")
+
+    def create_file(name, path):
+        out_fd.write(bytes([0x01])) # file
+        out_fd.write(bytes([len(name)])) # name length
+        out_fd.write(name.encode("ascii")) # name
+        fd = open(path, "rb")
+        file_content = fd.read()
+        fd.close()
+        out_fd.write(struct.pack("I", len(file_content))) # file size
+        out_fd.write(file_content) # file data
+
+    def create_directory(name, path):
+        out_fd.write(bytes([0x02])) # directory
+        out_fd.write(bytes([len(name)])) # name length
+        out_fd.write(name.encode("ascii")) # name
+        child_nodes = os.listdir(path)
+        out_fd.write(bytes([len(child_nodes)])) # child count
+        for child in child_nodes:
+            if(os.path.isdir(os.path.join(path, child))):
+                create_directory(child, os.path.join(path, child))
+            else:
+                create_file(child, os.path.join(path, child))
+    
+    create_directory("", dir_name) # root directory has no name
+
+    out_fd.close()
+    
+
+def main():
+    if len(sys.argv) <= 1:
+        print(f"Usage: {sys.argv[0]} <command>")
+        print("Commands:")
+        print("  create <file> <directory> | create a QROFS disk image file from a directory")
+        print("  extract <file> <directory> | extract the QROFS disk image file contents into a directory")
+    elif sys.argv[1] == "create":
+        if len(sys.argv) != 4:
+            print("Usage: create <file> <directory>")
+        else:
+            create(sys.argv[2], sys.argv[3])
+
+if(__name__ == "__main__"):
+    main()