diff --git a/myapps/first-hal/Makefile b/myapps/OLD/first-hal/Makefile
similarity index 100%
rename from myapps/first-hal/Makefile
rename to myapps/OLD/first-hal/Makefile
diff --git a/myapps/first-hal/hal.mk b/myapps/OLD/first-hal/hal.mk
similarity index 100%
rename from myapps/first-hal/hal.mk
rename to myapps/OLD/first-hal/hal.mk
diff --git a/myapps/first-hal/src/inc/stm32g0xx_hal_conf.h b/myapps/OLD/first-hal/src/inc/stm32g0xx_hal_conf.h
similarity index 100%
rename from myapps/first-hal/src/inc/stm32g0xx_hal_conf.h
rename to myapps/OLD/first-hal/src/inc/stm32g0xx_hal_conf.h
diff --git a/myapps/first-hal/src/inc/stm32g0xx_hal_msp.h b/myapps/OLD/first-hal/src/inc/stm32g0xx_hal_msp.h
similarity index 100%
rename from myapps/first-hal/src/inc/stm32g0xx_hal_msp.h
rename to myapps/OLD/first-hal/src/inc/stm32g0xx_hal_msp.h
diff --git a/myapps/first-hal/src/main.c b/myapps/OLD/first-hal/src/main.c
similarity index 100%
rename from myapps/first-hal/src/main.c
rename to myapps/OLD/first-hal/src/main.c
diff --git a/myapps/first-hal/src/stm32g0xx_hal_msp.c b/myapps/OLD/first-hal/src/stm32g0xx_hal_msp.c
similarity index 100%
rename from myapps/first-hal/src/stm32g0xx_hal_msp.c
rename to myapps/OLD/first-hal/src/stm32g0xx_hal_msp.c
diff --git a/myapps/first/Makefile b/myapps/OLD/first/Makefile
similarity index 100%
rename from myapps/first/Makefile
rename to myapps/OLD/first/Makefile
diff --git a/myapps/first/Makefile.bkp b/myapps/OLD/first/Makefile.bkp
similarity index 100%
rename from myapps/first/Makefile.bkp
rename to myapps/OLD/first/Makefile.bkp
diff --git a/myapps/first/hal.mk b/myapps/OLD/first/hal.mk
similarity index 100%
rename from myapps/first/hal.mk
rename to myapps/OLD/first/hal.mk
diff --git a/myapps/first/src/main.c b/myapps/OLD/first/src/main.c
similarity index 100%
rename from myapps/first/src/main.c
rename to myapps/OLD/first/src/main.c
diff --git a/myapps/OLD/practice/00-uart-tx/Makefile b/myapps/OLD/practice/00-uart-tx/Makefile
new file mode 100644
index 0000000..fb656c3
--- /dev/null
+++ b/myapps/OLD/practice/00-uart-tx/Makefile
@@ -0,0 +1,145 @@
+######################################
+# target
+######################################
+TARGET = stm32g0_blinky
+PART = STM32G030xx
+PYOCD_TARGET = stm32g030f6px
+
+
+######################################
+# building variables
+######################################
+# debug build?
+DEBUG = 1
+# optimization for size
+OPT = -Os
+
+
+#######################################
+# paths
+#######################################
+# Build path
+BUILD_DIR = build
+VND_DIR = ../../../vendor
+
+######################################
+# source
+######################################
+# C sources
+include hal.mk
+C_SOURCES += \
+$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Source/Templates/system_stm32g0xx.c \
+src/main.c
+
+
+# ASM sources
+ASM_SOURCES =  \
+$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Source/Templates/gcc/startup_stm32g030xx.s
+
+#######################################
+# binaries
+#######################################
+PREFIX = arm-none-eabi-
+
+CC = $(PREFIX)gcc
+CP = $(PREFIX)objcopy
+#SZ = $(PREFIX)size
+
+BIN = $(CP) -O binary -S
+
+#######################################
+# CFLAGS
+#######################################
+# cpu
+CPU = \
+ -mcpu=cortex-m0plus \
+ -mthumb
+
+DEFINES = -D$(PART)
+
+# fpu
+FPU = 
+
+# float-abi
+FLOAT-ABI =
+
+# mcu
+MCU = $(CPU) $(FPU) $(FLOAT-ABI)
+
+# C includes
+C_INCLUDES +=  \
+ -Isrc/inc \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Core/Include \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Include
+
+# compile gcc flags
+ADDN_CFLAGS = \
+ -Wall \
+ -fno-common \
+ -fdata-sections \
+ -ffunction-sections
+
+CFLAGS = $(MCU) $(ADDN_CFLAGS) $(C_INCLUDES) $(OPT) $(DEFINES)
+
+ifeq ($(DEBUG), 1)
+CFLAGS += -ggdb3
+endif
+
+
+# Generate dependency information
+#CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)"
+
+
+#######################################
+# LDFLAGS
+#######################################
+# link script
+LDSCRIPT = $(VND_DIR)/Ld/STM32G030F6MX_FLASH.ld
+
+LIBDIR = 
+LDFLAGS =  \
+ $(MCU)  \
+ -T $(LDSCRIPT) \
+ --specs=nano.specs \
+ -Wl,--gc-sections \
+ -Wl,--print-memory-usage \
+ -Wl,--no-warn-rwx-segments
+
+# default action: build all
+all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).bin
+
+
+#######################################
+# build the application
+#######################################
+# list of objects
+OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o)))
+vpath %.c $(sort $(dir $(C_SOURCES)))
+
+$(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR)
+	$(CC) -c $(CFLAGS) -Wa,-a,-ad,-alms=$(BUILD_DIR)/$(notdir $(<:.c=.lst)) $< -o $@
+
+#$(LUAOBJECTS) $(OBJECTS)
+$(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) Makefile
+	$(CC) $(OBJECTS) $(LDFLAGS) $(ASM_SOURCES) -o $@
+
+$(BUILD_DIR)/%.bin: $(BUILD_DIR)/%.elf | $(BUILD_DIR)
+	$(BIN) $< $@	
+	
+$(BUILD_DIR):
+	mkdir $@		
+
+#######################################
+# Program
+#######################################
+
+flash: $(BUILD_DIR)/$(TARGET).bin
+	pyocd load --target $(PYOCD_TARGET) $(BUILD_DIR)/$(TARGET).bin
+
+#######################################
+# clean up
+#######################################
+clean:
+	-rm -fR $(BUILD_DIR)
+  
+# *** EOF ***
diff --git a/myapps/OLD/practice/00-uart-tx/hal.mk b/myapps/OLD/practice/00-uart-tx/hal.mk
new file mode 100644
index 0000000..62dacbf
--- /dev/null
+++ b/myapps/OLD/practice/00-uart-tx/hal.mk
@@ -0,0 +1,20 @@
+C_INCLUDES += \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Inc
+
+
+C_SOURCES += \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_cortex.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr_ex.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc_ex.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_exti.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_dma.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_dma_ex.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_flash.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_flash_ex.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_gpio.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_uart.c \
+ src/stm32g0xx_hal_msp.c
+
diff --git a/myapps/practice/00-uart-tx/src/inc/stm32g0xx_hal_conf.h b/myapps/OLD/practice/00-uart-tx/src/inc/stm32g0xx_hal_conf.h
similarity index 100%
rename from myapps/practice/00-uart-tx/src/inc/stm32g0xx_hal_conf.h
rename to myapps/OLD/practice/00-uart-tx/src/inc/stm32g0xx_hal_conf.h
diff --git a/myapps/practice/00-uart-tx/src/inc/stm32g0xx_hal_msp.h b/myapps/OLD/practice/00-uart-tx/src/inc/stm32g0xx_hal_msp.h
similarity index 100%
rename from myapps/practice/00-uart-tx/src/inc/stm32g0xx_hal_msp.h
rename to myapps/OLD/practice/00-uart-tx/src/inc/stm32g0xx_hal_msp.h
diff --git a/myapps/OLD/practice/00-uart-tx/src/main.c b/myapps/OLD/practice/00-uart-tx/src/main.c
new file mode 100644
index 0000000..fcc20c3
--- /dev/null
+++ b/myapps/OLD/practice/00-uart-tx/src/main.c
@@ -0,0 +1,60 @@
+// Tx/Rx: PA09[PA11]/PA10[PA12]
+
+//#include <string.h>
+//#include <stdio.h>
+#include "stm32g0xx_hal_msp.h"
+
+UART_HandleTypeDef huart1;
+
+char buffer[] = "Hello World\r\n";
+#define TXBUFFERSIZE  14    //strlen(buffer)
+#define TIMEOUT 0xFFFF
+/*
+int __io_putchar(int ch)
+{
+  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, TIMEOUT);
+  return ch;
+}
+*/
+/*
+setvbuf(stout, NULL, _IOLBF, 0);
+
+int _write (int file, const void * ptr, size_t len)
+{
+  HAL_UART_Transmit(&huart1, ptr, len, TIMEOUT);
+  return len;
+}
+*/
+static void uart_init(void)
+{
+
+  huart1.Instance = USART1;   // Defined in CMSIS header as peripheral address
+  huart1.Init.BaudRate = 115200;
+  huart1.Init.WordLength = UART_WORDLENGTH_8B;
+  huart1.Init.StopBits = UART_STOPBITS_1;
+  huart1.Init.Parity = UART_PARITY_NONE;
+  huart1.Init.Mode = UART_MODE_TX_RX;
+  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
+  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
+  huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
+  huart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
+  huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
+  while (HAL_UART_Init(&huart1) != HAL_OK);
+
+}
+
+
+int main(void)
+{
+  HAL_Init();
+  SystemClock_Config();
+  uart_init();
+  
+  while(1)
+  {
+    HAL_UART_Transmit(&huart1, (uint8_t *)buffer, TXBUFFERSIZE, TIMEOUT);
+    //printf("Hello World\r\n");
+    HAL_Delay(100);
+  }
+}
+
diff --git a/myapps/practice/00-uart-tx/src/stm32g0xx_hal_msp.c b/myapps/OLD/practice/00-uart-tx/src/stm32g0xx_hal_msp.c
similarity index 100%
rename from myapps/practice/00-uart-tx/src/stm32g0xx_hal_msp.c
rename to myapps/OLD/practice/00-uart-tx/src/stm32g0xx_hal_msp.c
diff --git a/myapps/ll-hal-test/Makefile b/myapps/ll-hal-test/Makefile
new file mode 100644
index 0000000..8b57569
--- /dev/null
+++ b/myapps/ll-hal-test/Makefile
@@ -0,0 +1,154 @@
+######################################
+# target
+######################################
+TARGET = stm32g0_blinky
+PART = STM32G030xx
+PYOCD_TARGET = stm32g030f6px
+
+
+######################################
+# building variables
+######################################
+# debug build?
+DEBUG = 1
+# optimization for size
+OPT = -Os
+
+
+#######################################
+# paths
+#######################################
+# Build path
+BUILD_DIR = build
+VND_DIR = ../../vendor
+
+######################################
+# source
+######################################
+# C sources
+include hal.mk
+C_SOURCES += \
+$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Source/Templates/system_stm32g0xx.c \
+src/main.c
+
+
+# ASM sources
+ASM_SOURCES =  \
+$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Source/Templates/gcc/startup_stm32g030xx.s
+
+#######################################
+# binaries
+#######################################
+PREFIX = arm-none-eabi-
+
+CC = $(PREFIX)gcc
+CP = $(PREFIX)objcopy
+#SZ = $(PREFIX)size
+
+BIN = $(CP) -O binary -S
+
+#######################################
+# CFLAGS
+#######################################
+
+ifeq ($(DEBUG), 1)
+DEBUG_FLAGS = -gdwarf-3
+endif
+
+# cpu
+CPU = \
+ -mcpu=cortex-m0plus
+
+DEFINES = -D$(PART)
+
+# fpu
+FPU = 
+
+# float-abi
+FLOAT-ABI =
+
+# mcu
+MCU = $(CPU) $(FPU) $(FLOAT-ABI)
+
+# C includes
+C_INCLUDES +=  \
+ -Isrc/inc \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Core/Include \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/CMSIS/Device/ST/STM32G0xx/Include
+
+# compile gcc flags
+ADDN_CFLAGS = \
+ -Wall \
+ -fdata-sections \
+ -ffunction-sections
+
+CFLAGS = $(MCU) $(ADDN_CFLAGS) $(C_INCLUDES) $(DEBUG_FLAGS) $(OPT) $(DEFINES)
+
+
+# Generate dependency information
+#CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)"
+
+
+ASFLAGS = $(MCU) $(DEBUG_FLAGS) $(OPT) -Wa,--warn
+
+#######################################
+# LDFLAGS
+#######################################
+# link script
+LDSCRIPT = $(VND_DIR)/Ld/STM32G030F6MX_FLASH.ld
+
+LIBDIR = 
+LDFLAGS =  \
+ $(MCU)  \
+ -T $(LDSCRIPT) \
+ --specs=nano.specs \
+ -specs=nosys.specs -lc -lm \
+ -Wl,--gc-sections \
+ -Wl,--print-memory-usage \
+ -Wl,--no-warn-rwx-segments
+
+# default action: build all
+all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).bin
+
+
+#######################################
+# build the application
+#######################################
+# list of objects
+OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o)))
+vpath %.c $(sort $(dir $(C_SOURCES)))
+
+# list of ASM program objects
+OBJECTS += $(addprefix $(BUILD_DIR)/,$(notdir $(ASM_SOURCES:.s=.o)))
+vpath %.s $(sort $(dir $(ASM_SOURCES)))
+
+$(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR)
+	$(CC) -c $(CFLAGS) -Wa,-a,-ad,-alms=$(BUILD_DIR)/$(notdir $(<:.c=.lst)) $< -o $@
+
+$(BUILD_DIR)/%.o: %.s Makefile | $(BUILD_DIR)
+	$(CC) -c $(ASFLAGS) $< -o $@
+
+#$(LUAOBJECTS) $(OBJECTS)
+$(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) Makefile
+	$(CC) $(OBJECTS) $(LDFLAGS) -o $@
+
+$(BUILD_DIR)/%.bin: $(BUILD_DIR)/%.elf | $(BUILD_DIR)
+	$(BIN) $< $@	
+	
+$(BUILD_DIR):
+	mkdir $@		
+
+#######################################
+# Program
+#######################################
+
+flash: $(BUILD_DIR)/$(TARGET).bin
+	pyocd load --target $(PYOCD_TARGET) $(BUILD_DIR)/$(TARGET).bin
+
+#######################################
+# clean up
+#######################################
+clean:
+	-rm -fR $(BUILD_DIR)
+  
+# *** EOF ***
diff --git a/myapps/ll-hal-test/hal.mk b/myapps/ll-hal-test/hal.mk
new file mode 100644
index 0000000..1e754e6
--- /dev/null
+++ b/myapps/ll-hal-test/hal.mk
@@ -0,0 +1,13 @@
+C_INCLUDES += \
+ -I$(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Inc
+
+# "stm32g0xx_ll_bus.h" "stm32g0xx_ll_system.h" "stm32g0xx_ll_cortex.h" : missing
+C_SOURCES += \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_rcc.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_crs.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_exti.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_utils.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_pwr.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_dma.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_gpio.c
+
diff --git a/myapps/ll-hal-test/src/main.c b/myapps/ll-hal-test/src/main.c
new file mode 100644
index 0000000..363deb8
--- /dev/null
+++ b/myapps/ll-hal-test/src/main.c
@@ -0,0 +1,66 @@
+
+
+#define LED_Pin LL_GPIO_PIN_4
+#define LED_GPIO_Port GPIOA
+
+#include "stm32g0xx_ll_rcc.h"
+#include "stm32g0xx_ll_bus.h"
+#include "stm32g0xx_ll_crs.h"
+#include "stm32g0xx_ll_system.h"
+#include "stm32g0xx_ll_exti.h"
+#include "stm32g0xx_ll_cortex.h"
+#include "stm32g0xx_ll_utils.h"
+#include "stm32g0xx_ll_pwr.h"
+#include "stm32g0xx_ll_dma.h"
+#include "stm32g0xx_ll_gpio.h"
+
+void SystemClock_Config(void)
+{
+  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
+  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2);
+
+  /* HSI configuration and activation */
+  LL_RCC_HSI_Enable();
+  while(LL_RCC_HSI_IsReady() != 1);
+
+  /* Main PLL configuration and activation */
+  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI, LL_RCC_PLLM_DIV_1, 8, LL_RCC_PLLR_DIV_2);
+  LL_RCC_PLL_Enable();
+  LL_RCC_PLL_EnableDomain_SYS();
+  while(LL_RCC_PLL_IsReady() != 1);
+
+  /* Set AHB prescaler*/
+  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
+
+  /* Sysclk activation on the main PLL */
+  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
+  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL);
+
+  /* Set APB1 prescaler*/
+  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
+  LL_Init1msTick(64000000);
+  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
+  LL_SetSystemCoreClock(64000000);
+}
+
+
+int main(void)
+{
+  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
+  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SYSCFG);
+  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
+  /** Disable the internal Pull-Up in Dead Battery pins of UCPD peripheral */
+  //LL_SYSCFG_DisableDBATT(LL_SYSCFG_UCPD1_STROBE | LL_SYSCFG_UCPD2_STROBE);
+  
+  SystemClock_Config();
+  
+  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);
+  LL_GPIO_SetPinMode(LED_GPIO_Port, LL_GPIO_PIN_4, LL_GPIO_MODE_OUTPUT);
+  
+  while(1)
+  {
+    LL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);
+    LL_mDelay(250);
+  }
+}
+
diff --git a/myapps/practice/00-uart-tx/Makefile b/myapps/practice/00-uart-tx/Makefile
index fb656c3..530f750 100644
--- a/myapps/practice/00-uart-tx/Makefile
+++ b/myapps/practice/00-uart-tx/Makefile
@@ -50,10 +50,14 @@ BIN = $(CP) -O binary -S
 #######################################
 # CFLAGS
 #######################################
+
+ifeq ($(DEBUG), 1)
+DEBUG_FLAGS = -gdwarf-3
+endif
+
 # cpu
 CPU = \
- -mcpu=cortex-m0plus \
- -mthumb
+ -mcpu=cortex-m0plus
 
 DEFINES = -D$(PART)
 
@@ -75,21 +79,18 @@ C_INCLUDES +=  \
 # compile gcc flags
 ADDN_CFLAGS = \
  -Wall \
- -fno-common \
  -fdata-sections \
  -ffunction-sections
 
-CFLAGS = $(MCU) $(ADDN_CFLAGS) $(C_INCLUDES) $(OPT) $(DEFINES)
-
-ifeq ($(DEBUG), 1)
-CFLAGS += -ggdb3
-endif
+CFLAGS = $(MCU) $(ADDN_CFLAGS) $(C_INCLUDES) $(DEBUG_FLAGS) $(OPT) $(DEFINES)
 
 
 # Generate dependency information
 #CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)"
 
 
+ASFLAGS = $(MCU) $(DEBUG_FLAGS) $(OPT) -Wa,--warn
+
 #######################################
 # LDFLAGS
 #######################################
@@ -101,6 +102,7 @@ LDFLAGS =  \
  $(MCU)  \
  -T $(LDSCRIPT) \
  --specs=nano.specs \
+ -specs=nosys.specs -lc -lm \
  -Wl,--gc-sections \
  -Wl,--print-memory-usage \
  -Wl,--no-warn-rwx-segments
@@ -116,12 +118,19 @@ all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).bin
 OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o)))
 vpath %.c $(sort $(dir $(C_SOURCES)))
 
+# list of ASM program objects
+OBJECTS += $(addprefix $(BUILD_DIR)/,$(notdir $(ASM_SOURCES:.s=.o)))
+vpath %.s $(sort $(dir $(ASM_SOURCES)))
+
 $(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR)
 	$(CC) -c $(CFLAGS) -Wa,-a,-ad,-alms=$(BUILD_DIR)/$(notdir $(<:.c=.lst)) $< -o $@
 
+$(BUILD_DIR)/%.o: %.s Makefile | $(BUILD_DIR)
+	$(CC) -c $(ASFLAGS) $< -o $@
+
 #$(LUAOBJECTS) $(OBJECTS)
 $(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) Makefile
-	$(CC) $(OBJECTS) $(LDFLAGS) $(ASM_SOURCES) -o $@
+	$(CC) $(OBJECTS) $(LDFLAGS) -o $@
 
 $(BUILD_DIR)/%.bin: $(BUILD_DIR)/%.elf | $(BUILD_DIR)
 	$(BIN) $< $@	
diff --git a/myapps/practice/00-uart-tx/hal.mk b/myapps/practice/00-uart-tx/hal.mk
index 62dacbf..fa8b90a 100644
--- a/myapps/practice/00-uart-tx/hal.mk
+++ b/myapps/practice/00-uart-tx/hal.mk
@@ -1,20 +1,14 @@
 C_INCLUDES += \
  -I$(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Inc
 
-
+# "stm32g0xx_ll_bus.h" "stm32g0xx_ll_system.h" "stm32g0xx_ll_cortex.h" : missing
 C_SOURCES += \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_cortex.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_pwr_ex.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_rcc_ex.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_exti.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_dma.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_dma_ex.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_flash.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_flash_ex.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_gpio.c \
- $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_hal_uart.c \
- src/stm32g0xx_hal_msp.c
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_rcc.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_crs.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_exti.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_utils.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_pwr.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_dma.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_gpio.c \
+ $(VND_DIR)/STM32CubeG0/Drivers/STM32G0xx_HAL_Driver/Src/stm32g0xx_ll_usart.c
 
diff --git a/myapps/practice/00-uart-tx/src/main.c b/myapps/practice/00-uart-tx/src/main.c
index fcc20c3..a7491ab 100644
--- a/myapps/practice/00-uart-tx/src/main.c
+++ b/myapps/practice/00-uart-tx/src/main.c
@@ -1,60 +1,112 @@
-// Tx/Rx: PA09[PA11]/PA10[PA12]
 
-//#include <string.h>
-//#include <stdio.h>
-#include "stm32g0xx_hal_msp.h"
 
-UART_HandleTypeDef huart1;
+#include "stm32g0xx_ll_rcc.h"
+#include "stm32g0xx_ll_bus.h"
+#include "stm32g0xx_ll_crs.h"
+#include "stm32g0xx_ll_system.h"
+#include "stm32g0xx_ll_exti.h"
+#include "stm32g0xx_ll_cortex.h"
+#include "stm32g0xx_ll_utils.h"
+#include "stm32g0xx_ll_pwr.h"
+#include "stm32g0xx_ll_dma.h"
+#include "stm32g0xx_ll_gpio.h"
+#include "stm32g0xx_ll_usart.h"
 
-char buffer[] = "Hello World\r\n";
-#define TXBUFFERSIZE  14    //strlen(buffer)
-#define TIMEOUT 0xFFFF
-/*
-int __io_putchar(int ch)
+void SystemClock_Config(void)
 {
-  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, TIMEOUT);
-  return ch;
+  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
+  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2);
+
+  /* HSI configuration and activation */
+  LL_RCC_HSI_Enable();
+  while(LL_RCC_HSI_IsReady() != 1);
+
+  /* Main PLL configuration and activation */
+  LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI, LL_RCC_PLLM_DIV_1, 8, LL_RCC_PLLR_DIV_2);
+  LL_RCC_PLL_Enable();
+  LL_RCC_PLL_EnableDomain_SYS();
+  while(LL_RCC_PLL_IsReady() != 1);
+
+  /* Set AHB prescaler*/
+  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
+
+  /* Sysclk activation on the main PLL */
+  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
+  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL);
+
+  /* Set APB1 prescaler*/
+  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
+  LL_Init1msTick(64000000);
+  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
+  LL_SetSystemCoreClock(64000000);
 }
-*/
-/*
-setvbuf(stout, NULL, _IOLBF, 0);
 
-int _write (int file, const void * ptr, size_t len)
+void BSP_USART_Config(uint32_t baudRate)
 {
-  HAL_UART_Transmit(&huart1, ptr, len, TIMEOUT);
-  return len;
+    LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_USART2);
+
+    /* USART Init */
+    LL_USART_SetBaudRate(USART2, SystemCoreClock, LL_USART_PRESCALER_DIV1, LL_USART_OVERSAMPLING_16, baudRate);
+    LL_USART_SetDataWidth(USART2, LL_USART_DATAWIDTH_8B);
+    LL_USART_SetStopBitsLength(USART2, LL_USART_STOPBITS_1);
+    LL_USART_SetParity(USART2, LL_USART_PARITY_NONE);
+    LL_USART_SetHWFlowCtrl(USART2, LL_USART_HWCONTROL_NONE);
+    LL_USART_SetTransferDirection(USART2, LL_USART_DIRECTION_TX_RX);
+    LL_USART_Enable(USART2);
+    LL_USART_ClearFlag_TC(USART2);
+
+    /**USART GPIO Configuration
+    PA2     ------> USART2_TX
+    PA3     ------> USART2_RX
+    */
+    LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);
+
+    LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_2, LL_GPIO_MODE_ALTERNATE);
+    LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_2, LL_GPIO_SPEED_FREQ_VERY_HIGH);
+    LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_2, LL_GPIO_PULL_UP);
+    LL_GPIO_SetAFPin_0_7(GPIOA, LL_GPIO_PIN_2, LL_GPIO_AF_1);
+
+    LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_3, LL_GPIO_MODE_ALTERNATE);
+    LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_3, LL_GPIO_SPEED_FREQ_VERY_HIGH);
+    LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_3, LL_GPIO_PULL_UP);
+    LL_GPIO_SetAFPin_0_7(GPIOA, LL_GPIO_PIN_3, LL_GPIO_AF_1);
+
+//#if defined (__GNUC__) && !defined (__clang__)
+    // To avoid io buffer
+//    setvbuf(stdout, NULL, _IONBF, 0);
+//    setvbuf(stdin, NULL, _IONBF, 0);
+//#endif
 }
-*/
-static void uart_init(void)
+
+void BSP_UART_TxChar(char ch)
 {
+    LL_USART_TransmitData8(USART2, ch);
+    while (!LL_USART_IsActiveFlag_TC(USART2));
+    LL_USART_ClearFlag_TC(USART2);
+}
 
-  huart1.Instance = USART1;   // Defined in CMSIS header as peripheral address
-  huart1.Init.BaudRate = 115200;
-  huart1.Init.WordLength = UART_WORDLENGTH_8B;
-  huart1.Init.StopBits = UART_STOPBITS_1;
-  huart1.Init.Parity = UART_PARITY_NONE;
-  huart1.Init.Mode = UART_MODE_TX_RX;
-  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
-  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
-  huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
-  huart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
-  huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
-  while (HAL_UART_Init(&huart1) != HAL_OK);
-
+void BSP_UART_TxString(char *str)
+{
+    while (*str) BSP_UART_TxChar(*str++);
 }
 
 
 int main(void)
 {
-  HAL_Init();
+  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
+  LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SYSCFG);
+  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
+  /** Disable the internal Pull-Up in Dead Battery pins of UCPD peripheral */
+  //LL_SYSCFG_DisableDBATT(LL_SYSCFG_UCPD1_STROBE | LL_SYSCFG_UCPD2_STROBE);
+  
   SystemClock_Config();
-  uart_init();
+  
+  BSP_USART_Config(115200);
   
   while(1)
   {
-    HAL_UART_Transmit(&huart1, (uint8_t *)buffer, TXBUFFERSIZE, TIMEOUT);
-    //printf("Hello World\r\n");
-    HAL_Delay(100);
+    BSP_UART_TxString("Hello World\r\n");
+    LL_mDelay(500);
   }
+  
 }
-