From d511a57bff0259964ce29b6f93b3c42eef2e0372 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Mon, 24 Feb 2020 10:23:36 -0700
Subject: [PATCH] Add firmware struct to tool

---
 tool/src/firmware.rs | 48 ++++++++++++++++++++++++++++++++++++++++++++
 tool/src/lib.rs      |  3 +++
 2 files changed, 51 insertions(+)
 create mode 100644 tool/src/firmware.rs

diff --git a/tool/src/firmware.rs b/tool/src/firmware.rs
new file mode 100644
index 0000000..7b91b14
--- /dev/null
+++ b/tool/src/firmware.rs
@@ -0,0 +1,48 @@
+pub struct Firmware<'a> {
+    pub board: &'a [u8],
+    pub version: &'a [u8],
+    pub data: &'a [u8],
+}
+
+fn firmware_str<'a>(data: &'a [u8], key: &[u8]) -> Option<&'a [u8]> {
+    let mut data_i = 0;
+
+    //First, locate the key
+    let mut key_i = 0;
+    while data_i < data.len() && key_i < key.len() {
+        if data[data_i] == key[key_i] {
+            key_i += 1;
+        } else {
+            key_i = 0;
+        }
+        data_i += 1;
+    }
+
+    // Return None if key not found
+    if key_i < key.len() {
+        return None;
+    }
+
+    // Locate end of data
+    let start = data_i;
+    while data_i < data.len() {
+        if data[data_i] == 0 {
+            break;
+        }
+        data_i += 1;
+    }
+
+    Some(&data[start..data_i])
+}
+
+impl<'a> Firmware<'a> {
+    pub fn new(data: &'a [u8]) -> Option<Self> {
+        let board = firmware_str(data, b"76EC_BOARD=")?;
+        let version = firmware_str(data, b"76EC_VERSION=")?;
+        Some(Self {
+            data,
+            board,
+            version,
+        })
+    }
+}
diff --git a/tool/src/lib.rs b/tool/src/lib.rs
index b0d5a2d..da6dcd5 100644
--- a/tool/src/lib.rs
+++ b/tool/src/lib.rs
@@ -6,6 +6,9 @@ mod ec;
 pub use self::error::Error;
 mod error;
 
+pub use self::firmware::Firmware;
+mod firmware;
+
 pub use self::pmc::Pmc;
 mod pmc;