Add Qualcomm QDB (Qshrink Database) format

firmware/qualcomm_qdb.ksy

@@ -0,0 +1,30 @@
+meta:
+  id: qualcomm_qdb
+  title: Qualcomm Qshrink hash database file
+  application: Qualcomm QXDM
+  file-extension: qdb
+  license: CC0-1.0
+
+doc: |
+  This format is nothing more than zlib-compressed text appended to a trivially
+  simple binary header. The text, which is almost but not quite XML, maps
+  diagnostic codes emitted by Qualcomm modem firmware to textual log messages.
+  A file of this type typically resides on the "modem" partition of a Qualcomm
+  device with a name like "qdsp6m.qdb".
+
+doc-ref:
+  - https://github.com/mzakocs/qualcomm_baseband_scripts/blob/main/qshrink4_qdb_ghidra_script.py
+
+seq:
+  - id: magic
+    contents: [0x7f, "QDB"]
+  - id: guid
+    size: 0x10
+    doc: Matches the content's top-level <GUID> element
+
+instances:
+  content:
+    pos: 0x40
+    size-eos: true
+    process: zlib
+    doc: zlib-compressed text containing mapping entries and metadata