From b233347ca4fa640286bdb27baf2ce5024d917b19 Mon Sep 17 00:00:00 2001
From: able <abl3theabove@gmail.com>
Date: Wed, 20 Sep 2023 12:01:12 -0500
Subject: [PATCH] CPUID support

---
 .../src/arch/aarch64/device_info_collector.rs | 49 +++++++++++++++++++
 kernel/src/arch/aarch64/mod.rs                | 16 +++---
 2 files changed, 55 insertions(+), 10 deletions(-)
 create mode 100644 kernel/src/arch/aarch64/device_info_collector.rs

diff --git a/kernel/src/arch/aarch64/device_info_collector.rs b/kernel/src/arch/aarch64/device_info_collector.rs
new file mode 100644
index 0000000..dd200d3
--- /dev/null
+++ b/kernel/src/arch/aarch64/device_info_collector.rs
@@ -0,0 +1,49 @@
+use {
+    crate::{alloc::string::ToString, device_tree::DeviceTree, kmain::DEVICE_TREE},
+    alloc::string::String,
+    core::arch::asm,
+    xml::XMLElement,
+};
+
+pub fn collect_device_info() {
+    log::trace!("Collecting devices on aarch64");
+    // Lock device tree
+    unsafe {
+        DEVICE_TREE.force_unlock();
+    }
+    let device_tree = &mut DEVICE_TREE.lock();
+    collect_cpu_info(device_tree);
+    // let dt = DEVICE_TREE.lock();
+}
+
+fn collect_cpu_info(device_tree: &mut DeviceTree) {
+    let mut cpu = XMLElement::new("cpu");
+
+    let cpu_id = cpu_id();
+
+    cpu.set_attribute("CPU Name", cpu_id.0);
+    cpu.set_attribute("CPU Id", cpu_id.1);
+
+    let cpus = device_tree.devices.get_mut("CPUs").unwrap();
+    cpus.push(cpu);
+}
+
+fn cpu_id() -> (String, u64) {
+    let mut cpu_id: u64 = 0;
+    unsafe {
+        asm!("mrs {cpu_id}, MIDR_EL1",
+                cpu_id = out(reg) cpu_id,
+        )
+    }
+
+    let cpu_name = match cpu_id {
+        // the source of these two was a stackoverflow question
+        // https://raspberrypi.stackexchange.com/questions/117175/how-do-i-read-the-cpuid-in-aarch64-asm
+        0x410FD034 => "Cortex-A53".to_string(),
+        0x410FD083 => "Cortex-A72".to_string(),
+        _ => "Unknown".to_string(),
+    };
+    log::trace!("CPU Name: {cpu_name} - CPU ID: 0x{:X}", cpu_id);
+
+    (cpu_name, cpu_id)
+}
diff --git a/kernel/src/arch/aarch64/mod.rs b/kernel/src/arch/aarch64/mod.rs
index a6e359c..793288a 100644
--- a/kernel/src/arch/aarch64/mod.rs
+++ b/kernel/src/arch/aarch64/mod.rs
@@ -4,6 +4,9 @@ use {
     core::arch::asm,
     limine::FramebufferRequest,
 };
+mod device_info_collector;
+use device_info_collector::collect_device_info;
+
 pub mod logging;
 use limine::HhdmRequest;
 extern "C" {
@@ -14,22 +17,13 @@ const INITIAL_KERNEL_HEAP_START: *mut u8 = _initial_kernel_heap_start as _;
 const INITIAL_KERNEL_HEAP_SIZE: *const () = _initial_kernel_heap_size as _;
 
 pub const PAGE_SIZE: usize = 4096;
+static FB_REQ: FramebufferRequest = FramebufferRequest::new(0);
 
 #[no_mangle]
 unsafe extern "C" fn _kernel_start() -> ! {
     crate::logger::init().expect("failed to set logger");
     log::info!("Initialising AKern {}", crate::VERSION);
 
-    static FB_REQ: FramebufferRequest = FramebufferRequest::new(0);
-    let fb1 = &FB_REQ.get_response().get().unwrap().framebuffers()[0];
-
-    for i in 0..100_usize {
-        let offset = i * fb1.pitch as usize + i * 4;
-        unsafe {
-            *(fb1.address.as_ptr().unwrap().offset(offset as isize) as *mut u32) = 0xFFFFFFFF;
-        }
-    }
-
     static HDHM_REQ: HhdmRequest = HhdmRequest::new(0);
     // memory::init_pt(VirtAddr::new(
     //     HDHM_REQ
@@ -40,6 +34,8 @@ unsafe extern "C" fn _kernel_start() -> ! {
     // ));
     allocator::init(INITIAL_KERNEL_HEAP_START, INITIAL_KERNEL_HEAP_SIZE as _);
 
+    collect_device_info();
+
     let bm = MOD_REQ.get_response().get();
     use limine::{KernelFileRequest, ModuleRequest};
     static KFILE_REQ: KernelFileRequest = KernelFileRequest::new(0);