From 346e3e0ac818aa34dc3e165242a244ba60f96af6 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Mon, 6 Nov 2023 10:40:09 +0200
Subject: [PATCH] Implement iterator for the memory map

---
 Cargo.lock | 65 +++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml |  6 ++++
 src/lib.rs | 37 +++++++++++++++++++++++++
 src/v1.rs  | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 189 insertions(+)
 create mode 100644 Cargo.lock
 create mode 100644 src/v1.rs

diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 00000000..09f30391
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,65 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bytemuck"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17febce684fd15d89027105661fec94afb475cb995fbc59d2865198446ba2eea"
+dependencies = [
+ "bytemuck_derive",
+]
+
+[[package]]
+name = "bytemuck_derive"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fdde5c9cd29ebd706ce1b35600920a33550e402fc998a2e53ad3b42c3c47a192"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.66"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50f3b39ccfb720540debaa0164757101c08ecb8d326b15358ce76a62c7e85965"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b60f673f44a8255b9c8c657daf66a596d435f2da81a555b06dc644d080ba45e0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+
+[[package]]
+name = "yboot-proto"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 5da89265..feb2e8a7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,3 +6,9 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bytemuck = { version = "1.13.1", features = ["derive"] }
+
+[features]
+default = []
+dep-of-kernel = []
+dep-of-yboot = []
diff --git a/src/lib.rs b/src/lib.rs
index 0c9ac1ac..72c0e16b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1 +1,38 @@
+#![feature(const_mut_refs)]
 #![no_std]
+
+use bytemuck::{Pod, Zeroable};
+
+pub mod v1;
+
+pub use v1::LoadProtocol as LoadProtocolV1;
+
+pub const KERNEL_MAGIC: u32 = 0x1A2B3C4D;
+pub const LOADER_MAGIC: u32 = 0xD4C3B2A1;
+pub const PROTOCOL_VERSION_1: u32 = 1;
+
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+pub struct LoadProtocolHeader {
+    pub kernel_magic: u32,
+    pub version: u32,
+}
+
+pub trait AvailableRegion {
+    fn start_address(&self) -> usize;
+    fn page_count(&self) -> usize;
+}
+
+pub trait IterableMemoryMap<'a> {
+    type Entry: AvailableRegion + 'a;
+    type Iter: Iterator<Item = &'a Self::Entry> + Clone;
+
+    fn iter(&self) -> Self::Iter {
+        self.iter_with_offset(0)
+    }
+
+    fn iter_with_offset(&self, offset: usize) -> Self::Iter;
+
+    fn data_physical_base(&self) -> usize;
+    fn data_size(&self) -> usize;
+}
diff --git a/src/v1.rs b/src/v1.rs
new file mode 100644
index 00000000..5bf1290b
--- /dev/null
+++ b/src/v1.rs
@@ -0,0 +1,81 @@
+use core::mem::size_of;
+
+use bytemuck::{Pod, Zeroable};
+
+use crate::{AvailableRegion, IterableMemoryMap, LoadProtocolHeader};
+
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+pub struct LoadProtocol {
+    pub header: LoadProtocolHeader,
+    pub kernel_virt_offset: u64,
+
+    pub memory_map: MemoryMap,
+
+    pub rsdp_address: u64,
+    pub initrd_address: u64,
+    pub initrd_size: u64,
+
+    // Load options
+    pub opt_framebuffer: FramebufferOption,
+}
+
+#[derive(Clone, Copy, Debug)]
+#[repr(C)]
+pub struct AvailableMemoryRegion {
+    pub start_address: u64,
+    pub page_count: u64,
+}
+
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+pub struct MemoryMap {
+    pub address: u64,
+    pub len: u64,
+}
+
+// TODO specify format etc.
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(C)]
+pub struct FramebufferOption {
+    pub req_width: u32,
+    pub req_height: u32,
+
+    pub res_width: u32,
+    pub res_height: u32,
+    pub res_stride: u64,
+    pub res_address: u64,
+    pub res_size: u64,
+}
+
+impl AvailableRegion for AvailableMemoryRegion {
+    fn start_address(&self) -> usize {
+        self.start_address as _
+    }
+
+    fn page_count(&self) -> usize {
+        self.page_count as _
+    }
+}
+
+impl IterableMemoryMap<'static> for MemoryMap {
+    type Entry = AvailableMemoryRegion;
+    type Iter = core::slice::Iter<'static, AvailableMemoryRegion>;
+
+    fn iter_with_offset(&self, offset: usize) -> Self::Iter {
+        let virt_address = self.address + offset as u64;
+        let slice = unsafe {
+            core::slice::from_raw_parts(virt_address as *const AvailableMemoryRegion, self.len as _)
+        };
+
+        slice.iter()
+    }
+
+    fn data_physical_base(&self) -> usize {
+        self.address as _
+    }
+
+    fn data_size(&self) -> usize {
+        self.len as usize * size_of::<AvailableMemoryRegion>()
+    }
+}