diff --git a/inc/f4ll/console_handler.h b/inc/f4ll/console_handler.h
index 14e15a6..9ab5e4a 100644
--- a/inc/f4ll/console_handler.h
+++ b/inc/f4ll/console_handler.h
@@ -8,10 +8,8 @@
 #pragma once
 
 #include <f4ll/initialized_singleton.h>
+#include <f4ll/packet_usart.h>
 #include <f4ll/ringbuffer.h>
-#include <f4ll/usart_core.h>
-
-#include <platform/dma_ll.h>
 
 namespace f4ll {
 
@@ -42,16 +40,16 @@ private:
     void setup_receive(void);
 
     // LL_UsartCore pure virtual function implementations
-    void receiver_idle(void) override;
-    void transmission_complete(void) override;
-    void framing_error(void) override;
-    void overrun(void) override;
-    void rx_dma_transfer_complete(void) override;
-    void rx_dma_half_transfer(void) override;
-    void rx_dma_error(dma_helper::dma_error_type reason) override;
-    void tx_dma_transfer_complete(void) override;
-    void tx_dma_half_transfer(void) override;
-    void tx_dma_error(dma_helper::dma_error_type reason) override;
+    virtual void receiver_idle(void) override;
+    virtual void transmission_complete(void) override;
+    virtual void framing_error(void) override;
+    virtual void overrun(void) override;
+    virtual void rx_dma_transfer_complete(void) override;
+    virtual void rx_dma_half_transfer(void) override;
+    virtual void rx_dma_error(dma_helper::dma_error_type reason) override;
+    virtual void tx_dma_transfer_complete(void) override;
+    virtual void tx_dma_half_transfer(void) override;
+    virtual void tx_dma_error(dma_helper::dma_error_type reason) override;
 
     ringbuffer_ext m_tx_buffer;
     size_type m_bytes_sent = 0;
diff --git a/inc/f4ll/crc_handler.h b/inc/f4ll/crc_handler.h
index fbc7037..8fb6b27 100644
--- a/inc/f4ll/crc_handler.h
+++ b/inc/f4ll/crc_handler.h
@@ -6,12 +6,10 @@
  */
 #pragma once
 
-#include <cstdint>
-
-#include <platform/dma_ll.h>
-
 #include <f4ll/dma_helper.h>
 #include <f4ll/initialized_singleton.h>
+#include <inttypes.h>
+#include <platform/dma_ll.h>
 
 namespace f4ll {
 
diff --git a/inc/f4ll/dma_helper.h b/inc/f4ll/dma_helper.h
index 4f52f1e..0b8719e 100644
--- a/inc/f4ll/dma_helper.h
+++ b/inc/f4ll/dma_helper.h
@@ -7,8 +7,7 @@
 
 #pragma once
 
-#include <cstdint>
-
+#include <inttypes.h>
 #include <platform/dma_ll.h>
 
 namespace f4ll {
diff --git a/inc/f4ll/fault.h b/inc/f4ll/fault.h
index 42293c4..8bb1f2e 100644
--- a/inc/f4ll/fault.h
+++ b/inc/f4ll/fault.h
@@ -5,8 +5,6 @@
 #define FAULT_REASON_BUS_FAULT 3
 #define FAULT_REASON_USAGE_FAULT 4
 
-#include <cstdint>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/inc/f4ll/irq_lock.h b/inc/f4ll/irq_lock.h
index 6d4b356..b36ef75 100644
--- a/inc/f4ll/irq_lock.h
+++ b/inc/f4ll/irq_lock.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <cstdint>
+#include <inttypes.h>
 #include <stm32f4xx.h>
 
 namespace f4ll {
diff --git a/inc/f4ll/memcpy_dma.h b/inc/f4ll/memcpy_dma.h
index ab728d1..4fcd299 100644
--- a/inc/f4ll/memcpy_dma.h
+++ b/inc/f4ll/memcpy_dma.h
@@ -6,8 +6,6 @@
  */
 #pragma once
 
-#include <cstdint>
-
 #include <f4ll/dma_helper.h>
 #include <f4ll/initialized_singleton.h>
 
diff --git a/inc/f4ll/packet_usart.h b/inc/f4ll/packet_usart.h
index 0fd425c..1bb9a96 100644
--- a/inc/f4ll/packet_usart.h
+++ b/inc/f4ll/packet_usart.h
@@ -95,7 +95,7 @@ private:
     virtual void tx_dma_half_transfer(void) override;
     virtual void tx_dma_error(dma_helper::dma_error_type reason) override;
 
-    struct buffer
+    struct Buffer
     {
         packet pkt;
         // transfer area ends here
@@ -115,8 +115,8 @@ private:
     crc_handler::slot<2> m_crc_slot;
     ihs_usart_callback *m_user_callback = nullptr;
     uintptr_t m_user_callback_param = 0;
-    buffer m_tx_buffer;
-    buffer m_rx_buffers[2];
+    Buffer m_tx_buffer;
+    Buffer m_rx_buffers[2];
 };
 
 }
diff --git a/inc/f4ll/ringbuffer.h b/inc/f4ll/ringbuffer.h
index c2dc08d..82f1891 100644
--- a/inc/f4ll/ringbuffer.h
+++ b/inc/f4ll/ringbuffer.h
@@ -9,6 +9,7 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <cstring>
 
 namespace f4ll {
 
@@ -130,4 +131,4 @@ ringbuffer<SZ>::ringbuffer()
 {
 }
 
-} // namespace f1ll
+} // namespace f1ll
\ No newline at end of file
diff --git a/inc/f4ll/singleton.h b/inc/f4ll/singleton.h
deleted file mode 100644
index b4278a8..0000000
--- a/inc/f4ll/singleton.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#pragma once
-
-namespace f4ll {
-
-template <typename T> class singleton
-{
-public:
-    static T &instance()
-    {
-        static T instance;
-        return instance;
-    }
-
-protected:
-    singleton() = default;
-    singleton(const singleton &) = delete;
-    singleton &operator=(const singleton &) = delete;
-    static T *m_instance;
-};
-
-template <typename T> T *singleton<T>::m_instance = nullptr;
-
-} //  namespace f1ll {
diff --git a/src/console_handler.cpp b/src/console_handler.cpp
index e1955f1..2ddd37d 100644
--- a/src/console_handler.cpp
+++ b/src/console_handler.cpp
@@ -5,7 +5,9 @@
  *      Author: abody
  */
 
+#include <cstddef>
 #include <f4ll/console_handler.h>
+#include <f4ll/irq_lock.h>
 #include <f4ll/str_util.h>
 
 #include <cstring>
diff --git a/src/fault.cpp b/src/fault.cpp
index d26d544..83ae3c2 100644
--- a/src/fault.cpp
+++ b/src/fault.cpp
@@ -5,6 +5,8 @@
  *      Author: abody
  *      -c "tpiu config internal <logfile_full_path> uart off <cpufreq>"
  */
+#include <inttypes.h>
+// #include <core_cm4.h>
 #include <f4ll/fault.h>
 #include <f4ll/str_util.h>
 #include <stm32f4xx.h>
diff --git a/src/packet_usart.cpp b/src/packet_usart.cpp
index a1945b6..046d5ea 100644
--- a/src/packet_usart.cpp
+++ b/src/packet_usart.cpp
@@ -183,7 +183,7 @@ void packet_usart::crc_succeeded(uintptr_t callback_param, uint32_t crc, uint8_t
 {
     (void)task;
 
-    buffer &buf(m_rx_buffers[static_cast<int>(callback_param)]);
+    Buffer &buf(m_rx_buffers[static_cast<int>(callback_param)]);
 
     buf.busy = 1;
     if (*(uint32_t *)(buf.pkt.payload + round_up_to_4((uint16_t)buf.pkt.header.payload_length)) != crc) {
@@ -201,7 +201,7 @@ void packet_usart::crc_failed(uintptr_t callback_param, uint32_t crc, uint8_t ta
     (void)crc;
     (void)task;
 
-    buffer &buf(m_rx_buffers[static_cast<int>(callback_param)]);
+    Buffer &buf(m_rx_buffers[static_cast<int>(callback_param)]);
     buf.busy = buf.error = true;
     buf.error_info = 0;
     ++m_stats.payload_errror;
diff --git a/src/ringbuffer.cpp b/src/ringbuffer.cpp
index ae81ac2..c5a46e3 100644
--- a/src/ringbuffer.cpp
+++ b/src/ringbuffer.cpp
@@ -1,7 +1,5 @@
 #include <f4ll/ringbuffer.h>
 
-#include <cstring>
-
 namespace f4ll {
 
 ringbuffer_ext::ringbuffer_ext(uint8_t *bptr, size_type bsize)
@@ -149,4 +147,4 @@ iringbuffer::size_type ringbuffer_ext::marker_diff(size_type m1, size_type m2) c
 }
 
 //
-}
+}
\ No newline at end of file
diff --git a/src/str_util.cpp b/src/str_util.cpp
index 9b6ef95..54b95df 100644
--- a/src/str_util.cpp
+++ b/src/str_util.cpp
@@ -1,5 +1,7 @@
 #include <f4ll/str_util.h>
 
+#include <cstdint>
+
 //////////////////////////////////////////////////////////////////////////////
 size_t strcpy_ex(char *dst, char const *src)
 {