add specification for Reolink firmware files

firmware/reolink.ksy

@@ -0,0 +1,113 @@
+meta:
+  id: reolink_pak
+  title: Reolink firmware update
+  file-extension: pak
+  license: MIT
+  endian: le
+  encoding: UTF-8
+doc-ref:
+  - https://github.com/vmallet/pakler/blob/acbf084b/pakler/__init__.py
+seq:
+  - id: header
+    type:
+      switch-on: is_64
+      cases:
+        true: header64
+        false: header32
+  - id: sections
+    type:
+      switch-on: is_64
+      cases:
+        false: section32
+        true: section64
+    repeat: expr
+    repeat-expr: num_sections
+  - id: partitions
+    type: partition
+    repeat: expr
+    repeat-expr: num_sections
+instances:
+  header_crc32:
+    pos: 4
+    type: u4
+  is_64:
+    value: header_crc32 == 0
+  num_sections:
+    value: header.as<header32>.num_sections
+types:
+  header32:
+    seq:
+      - id: magic
+        contents: [0x13, 0x59, 0x72, 0x32]
+      - id: crc32
+        type: u4
+      - id: board
+        size: 4
+    instances:
+      first_section:
+        io: _root._io
+        pos: sizeof<header32>
+        type: section32
+      num_sections:
+        value: (first_section.ofs_section - sizeof<header32>) / (sizeof<section32> + sizeof<partition>)
+  header64:
+    seq:
+      - id: magic
+        contents: [0x13, 0x59, 0x72, 0x32, 0x00, 0x00, 0x00, 0x00]
+      - id: crc32
+        type: u8
+      - id: board
+        size: 8
+    instances:
+      first_section:
+        io: _root._io
+        pos: sizeof<header64>
+        type: section64
+      num_sections:
+        value: (first_section.ofs_section - sizeof<header64>) / (sizeof<section64> + sizeof<partition>)
+  section32:
+    seq:
+      - id: name
+        size: 32
+        type: strz
+      - id: version
+        size: 24
+      - id: ofs_section
+        type: u4
+      - id: len_section
+        type: u4
+    instances:
+      section:
+        io: _root._io
+        pos: ofs_section
+        size: len_section
+  section64:
+    seq:
+      - id: name
+        size: 32
+        type: strz
+      - id: version
+        size: 24
+      - id: ofs_section
+        type: u8
+      - id: len_section
+        type: u8
+    instances:
+      section:
+        io: _root._io
+        pos: ofs_section
+        size: len_section
+  partition:
+    seq:
+      - id: name
+        size: 32
+        type: strz
+      - id: ofs_partition
+        type: u4
+      - id: mtd
+        size: 32
+        type: strz
+      - id: start_address
+        size: 4
+      - id: len_partition
+        type: u4