arm: add host uart driver tests

All host tests currently pass
Some async refactors may not work well on device, will try later

arm/ring_buffer.h

@@ -3,6 +3,8 @@
 #include <atomic>
 #include <span>
 
+#include "lock.h"
+
 struct RingBuffer {
     std::span<std::byte> buffer;
 
@@ -11,6 +13,8 @@ struct RingBuffer {
     std::atomic<bool> full = 0;
 
     bool Store(std::span<const std::byte> data) {
+        InterruptLock lock;
+
         if (data.size() > FreeSpace()) {
             return false;
         }
@@ -26,6 +30,8 @@ struct RingBuffer {
     }
 
     bool Load(std::span<std::byte> out) {
+        InterruptLock lock;
+
         if (out.size() > AvailableData()) {
             return false;
         }
@@ -41,6 +47,8 @@ struct RingBuffer {
     }
 
     bool Push(size_t amount) {
+        InterruptLock lock;
+
         if (amount > FreeSpace()) {
             return false;
         }
@@ -52,6 +60,8 @@ struct RingBuffer {
     }
 
     bool Pop(size_t amount) {
+        InterruptLock lock;
+
         if (amount > AvailableData()) {
             return false;
         }
@@ -62,9 +72,15 @@ struct RingBuffer {
         return true;
     }
 
-    size_t FreeSpace() const { return buffer.size() - AvailableData(); }
+    size_t FreeSpace() const {
+        InterruptLock lock;
+
+        return buffer.size() - AvailableData();
+    }
 
     size_t AvailableData() const {
+        InterruptLock lock;
+
         if (read_ptr == write_ptr) {
             return full ? buffer.size() : 0;
         }
@@ -72,10 +88,14 @@ struct RingBuffer {
     }
 
     uint8_t* RawReadPointer() const {
+        InterruptLock lock;
+
         return reinterpret_cast<uint8_t*>(buffer.data() + read_ptr);
     }
 
     size_t ContiguousAvailableData() const {
+        InterruptLock lock;
+
         if (read_ptr < write_ptr) {
             return AvailableData();
         }