Add Phoenix EVSA parser

common/ksy/phoenix_evsa.ksy

@@ -0,0 +1,99 @@
+meta:
+  id: phoenix_evsa
+  title: Phoenix EVSA NVRAM store
+  application: Phoenix-based UEFI firmware
+  file-extension: evsa
+  tags:
+    - firmware
+  license: CC0-1.0
+  ks-version: 0.9
+  endian: le
+  
+seq:
+- id: type
+  type: u1
+  valid: 0xEC
+- id: checksum
+  type: u1
+- id: size
+  type: u2
+  valid: 20
+- id: signature
+  type: u4
+  valid: 0x41535645
+- id: attributes
+  type: u4
+- id: store_size
+  type: u4
+- id: reserved
+  type: u4
+- id: body
+  type: evsa_body
+  size: store_size - 20
+  
+types:
+  evsa_guid:
+   seq:
+   - id: guid_id
+     type: u2
+   - id: guid
+     size: 16
+
+  evsa_name:
+   seq:
+   - id: var_id
+     type: u2
+   - id: name
+     size: _parent.size - 6
+
+  evsa_data:
+   seq:
+   - id: guid_id
+     type: u2
+   - id: var_id
+     type: u2
+   - id: attributes
+     type: u4
+   - id: data_size
+     type: u4
+     if: (attributes & 0x10000000) != 0x10000000
+   - id: data
+     size:  _parent.size - 12
+     if: (attributes & 0x10000000) == 0x10000000
+   - id: data_ext
+     size: data_size
+     if: (attributes & 0x10000000) != 0x10000000
+
+  evsa_unknown:
+   seq:
+   - id: unknown 
+     size: 0
+     
+  evsa_entry:
+   seq:
+   - id: type
+     type: u1
+   - id: checksum
+     type: u1
+   - id: size
+     type: u2
+   - id: body
+     type:
+      switch-on: type
+      cases:
+        0xED: evsa_guid
+        0xE1: evsa_guid
+        0xEE: evsa_name
+        0xE2: evsa_name
+        0xEF: evsa_data
+        0xE3: evsa_data
+        0x83: evsa_data
+        _:    evsa_unknown
+        
+  evsa_body:
+   seq:
+   - id: entries
+     type: evsa_entry
+     repeat: eos
+        
+