Add Apple SysF/Diag parser

common/ksy/apple_fsys.ksy

@@ -0,0 +1,60 @@
+meta:
+  id: apple_sysf
+  title: Apple system variable store
+  application: Apple MacEFI-based UEFI firmware
+  file-extension: sysf
+  tags:
+    - firmware
+  license: CC0-1.0
+  ks-version: 0.9
+  endian: le
+  
+seq:
+- id: signature
+  type: u4
+  valid:
+   expr: _ == 0x73797346 or _ == 0x64696147 # Fsys/Gaid
+- id: unknown
+  type: u1
+- id: unknown1
+  type: u4
+- id: sysf_size
+  type: u2
+- id: body
+  type: sysf_store_body
+  size: sysf_size - len_sysf_store_header - sizeof<u4>
+- id: crc
+  type: u4
+
+instances:
+  len_sysf_store_header:
+   value: 11
+
+types:
+ sysf_store_body:
+  seq:
+  - id: variables
+    type: sysf_variable
+    repeat: until
+    repeat-until: (_.len_name == 3 and _.name == "EOF") or _io.eof
+  - id: zeroes
+    type: u1
+    repeat: eos
+    
+ sysf_variable:
+  seq:
+  - id: len_name
+    type: b7le
+  - id: invalid_flag
+    type: b1le
+  - id: name
+    type: strz
+    encoding: ascii
+    size: len_name
+  - id: len_data
+    type: u2
+    if: name != "EOF"
+  - id: data
+    size: len_data
+    if: name != "EOF"
+