Stub out reading registers and memory

src/gdbserver/response.rs

@@ -1,3 +1,5 @@
+use num_traits::ToBytes;
+
 pub struct Response {
     buffer: Vec<u8>,
     checksum: u8,
@@ -17,22 +19,24 @@ impl Response {
     }
 
     pub fn write_str(mut self, str: &str) -> Self {
-        for char in str.as_bytes() {
-            self.buffer.push(*char);
-            self.checksum = self.checksum.wrapping_add(*char);
+        for byte in str.as_bytes() {
+            self.buffer.push(*byte);
+            self.checksum = self.checksum.wrapping_add(*byte);
         }
         self
     }
 
-    pub fn write_hex_u8(mut self, value: u8) -> Self {
-        for digit in [(value >> 4), (value & 0xf)] {
-            let char = if digit > 9 {
-                b'a' + digit - 10
-            } else {
-                b'0' + digit
-            };
-            self.buffer.push(char);
-            self.checksum = self.checksum.wrapping_add(char);
+    pub fn write_hex<T: ToBytes>(mut self, value: T) -> Self {
+        for byte in value.to_be_bytes().as_ref() {
+            for digit in [(byte >> 4), (byte & 0xf)] {
+                let char = if digit > 9 {
+                    b'a' + digit - 10
+                } else {
+                    b'0' + digit
+                };
+                self.buffer.push(char);
+                self.checksum = self.checksum.wrapping_add(char);
+            }
         }
         self
     }
@@ -40,6 +44,6 @@ impl Response {
     pub fn finish(mut self) -> Vec<u8> {
         let checksum = self.checksum;
         self.buffer.push(b'#');
-        self.write_hex_u8(checksum).buffer
+        self.write_hex(checksum).buffer
     }
 }