refactor mega-commit.

- reorganised the entire project so that the entire kernel is a single codebase rather than a kernel and a libk.

kernel/src/arch/x86_64/cpu/msr.rs

@@ -0,0 +1,24 @@
+use core::arch::x86_64::__cpuid;
+use spin::Lazy;
+use x86_64::registers::model_specific::Msr;
+
+const CPUID_FLAG_MSR: u32 = 1 << 5;
+static EDX: Lazy<u32> = Lazy::new(|| unsafe { __cpuid(1).edx });
+
+pub fn cpu_has_msr() -> bool {
+    *EDX & CPUID_FLAG_MSR != 0
+}
+
+pub fn cpu_get_msr(msr: u32, value: &mut u64) {
+    let msr = Msr::new(msr);
+    unsafe {
+        *value = msr.read();
+    }
+}
+
+pub fn cpu_set_msr(msr: u32, value: u64) {
+    let mut msr = Msr::new(msr);
+    unsafe {
+        msr.write(value);
+    }
+}