Allow setting the ramdisk location via bootloader config

Author: jasoncouture

api/build.rs

@@ -22,6 +22,7 @@ fn main() {
         (88, 9),
         (97, 9),
         (106, 9),
+        (115, 9)
     ];
 
     let mut code = String::new();

api/src/config.rs

@@ -35,7 +35,7 @@ impl BootloaderConfig {
         0x3D,
     ];
     #[doc(hidden)]
-    pub const SERIALIZED_LEN: usize = 115;
+    pub const SERIALIZED_LEN: usize = 124;
 
     /// Creates a new default configuration with the following values:
     ///
@@ -77,6 +77,7 @@ impl BootloaderConfig {
             aslr,
             dynamic_range_start,
             dynamic_range_end,
+            ramdisk_memory,
         } = mappings;
         let FrameBuffer {
             minimum_framebuffer_height,
@@ -133,13 +134,15 @@ impl BootloaderConfig {
             },
         );
 
-        concat_106_9(
+        let buf = concat_106_9(
             buf,
             match minimum_framebuffer_width {
                 Option::None => [0; 9],
                 Option::Some(addr) => concat_1_8([1], addr.to_le_bytes()),
             },
-        )
+        );
+
+        concat_115_9(buf, ramdisk_memory.serialize())
     }
 
     /// Tries to deserialize a config byte array that was created using [`Self::serialize`].
@@ -197,6 +200,7 @@ impl BootloaderConfig {
             let (&dynamic_range_start, s) = split_array_ref(s);
             let (&dynamic_range_end_some, s) = split_array_ref(s);
             let (&dynamic_range_end, s) = split_array_ref(s);
+            let (&ramdisk_memory, s) = split_array_ref(s);
 
             let mappings = Mappings {
                 kernel_stack: Mapping::deserialize(&kernel_stack)?,
@@ -227,6 +231,7 @@ impl BootloaderConfig {
                     [1] => Option::Some(u64::from_le_bytes(dynamic_range_end)),
                     _ => return Err("invalid dynamic range end value"),
                 },
+                ramdisk_memory: Mapping::deserialize(&ramdisk_memory)?
             };
             (mappings, s)
         };
@@ -381,6 +386,9 @@ pub struct Mappings {
     ///
     /// Defaults to `0xffff_ffff_ffff_f000`.
     pub dynamic_range_end: Option<u64>,
+    /// Virtual address to map ramdisk image, if present on disk
+    /// Defaults to dynamic
+    pub ramdisk_memory: Mapping
 }
 
 impl Mappings {
@@ -397,6 +405,7 @@ impl Mappings {
             aslr: false,
             dynamic_range_start: None,
             dynamic_range_end: None,
+            ramdisk_memory: Mapping::new_default()
         }
     }
 
@@ -429,6 +438,7 @@ impl Mappings {
             } else {
                 Option::None
             },
+            ramdisk_memory: Mapping::random()
         }
     }
 }