From 433cc7dfb7183c545c2de803be5a2d98a3c8ee70 Mon Sep 17 00:00:00 2001
From: bunnie <bunnie@kosagi.com>
Date: Thu, 2 May 2024 22:16:55 +0800
Subject: [PATCH] add platform dependent implementations

this allows us to get rid of traits. woo!
---
 .../xous-swapper/src/platform/cramium/hw.rs    | 14 ++++++++++++++
 .../xous-swapper/src/platform/cramium/mod.rs   |  1 +
 services/xous-swapper/src/platform/mod.rs      |  9 +++++++++
 .../xous-swapper/src/platform/precursor/hw.rs  | 18 ++++++++++++++++++
 .../xous-swapper/src/platform/precursor/mod.rs |  1 +
 5 files changed, 43 insertions(+)
 create mode 100644 services/xous-swapper/src/platform/cramium/hw.rs
 create mode 100644 services/xous-swapper/src/platform/cramium/mod.rs
 create mode 100644 services/xous-swapper/src/platform/mod.rs
 create mode 100644 services/xous-swapper/src/platform/precursor/hw.rs
 create mode 100644 services/xous-swapper/src/platform/precursor/mod.rs

diff --git a/services/xous-swapper/src/platform/cramium/hw.rs b/services/xous-swapper/src/platform/cramium/hw.rs
new file mode 100644
index 000000000..b903030c9
--- /dev/null
+++ b/services/xous-swapper/src/platform/cramium/hw.rs
@@ -0,0 +1,14 @@
+/// This is an implementation for SMTs that are accessible only through a SPI
+/// register interface. The base and bounds must be translated to SPI accesses
+/// in a hardware-specific manner.
+pub struct SwapMac {
+    pub base: usize,
+    pub bounds: usize,
+}
+impl SwapMac {
+    pub fn new(base: usize, bounds: usize) -> Self { SwapMac { base, bounds } }
+
+    pub fn lookup_mac(&self, swap_page_offset: usize) -> [u8; 16] { todo!() }
+
+    pub fn store_mac(&mut self, swap_page_offset: usize, mac: &[u8; 16]) { todo!() }
+}
diff --git a/services/xous-swapper/src/platform/cramium/mod.rs b/services/xous-swapper/src/platform/cramium/mod.rs
new file mode 100644
index 000000000..e21a96e0a
--- /dev/null
+++ b/services/xous-swapper/src/platform/cramium/mod.rs
@@ -0,0 +1 @@
+pub mod hw;
diff --git a/services/xous-swapper/src/platform/mod.rs b/services/xous-swapper/src/platform/mod.rs
new file mode 100644
index 000000000..701b9c807
--- /dev/null
+++ b/services/xous-swapper/src/platform/mod.rs
@@ -0,0 +1,9 @@
+#[cfg(any(feature = "cramium-soc"))]
+pub mod cramium;
+#[cfg(any(feature = "cramium-soc"))]
+pub use cramium::hw::*;
+
+#[cfg(any(feature = "precursor", feature = "renode"))]
+pub mod precursor;
+#[cfg(any(feature = "precursor", feature = "renode"))]
+pub use precursor::hw::*;
diff --git a/services/xous-swapper/src/platform/precursor/hw.rs b/services/xous-swapper/src/platform/precursor/hw.rs
new file mode 100644
index 000000000..e614c1247
--- /dev/null
+++ b/services/xous-swapper/src/platform/precursor/hw.rs
@@ -0,0 +1,18 @@
+/// This defines a set of functions to get and receive MACs (message
+/// authentication codes, also referred to as the tag in AES-GCM-SIV.
+pub struct SwapMac {
+    pub macs: &'static mut [[u8; 16]],
+}
+impl SwapMac {
+    pub fn new(base: usize, bounds: usize) -> Self {
+        SwapMac {
+            // safety: this is only safe because the loader guarantees memory-mapped SMT is initialized and
+            // aligned and properly mapped into the swapper's memory space.
+            macs: unsafe { core::slice::from_raw_parts_mut(base as *mut [u8; 16], bounds as usize / 16) },
+        }
+    }
+
+    pub fn lookup_mac(&self, swap_page_offset: usize) -> [u8; 16] { todo!() }
+
+    pub fn store_mac(&mut self, swap_page_offset: usize, mac: &[u8; 16]) { todo!() }
+}
diff --git a/services/xous-swapper/src/platform/precursor/mod.rs b/services/xous-swapper/src/platform/precursor/mod.rs
new file mode 100644
index 000000000..e21a96e0a
--- /dev/null
+++ b/services/xous-swapper/src/platform/precursor/mod.rs
@@ -0,0 +1 @@
+pub mod hw;