Added Lab3 example which is built for STM32F4 Discovery Kit and run on Renode Simulator and displays results of unit tests on UART terminal

Author: Bharathgopal

.github/workflows/build.yml

@@ -21,3 +21,9 @@ jobs:
         run: |
           make -C Lab2
           ./Lab2/Lab2
+      - name: Install Renode
+        run: |
+          .Lab3/install_renode.sh
+      - name: Build and Run Lab3
+        run: |
+          make run -C Lab3

Lab2/checksum.c

@@ -1,7 +1,12 @@
 #include "checksum.h"
+#include <stddef.h>
 
 uint8_t calculate_checksum(uint8_t *buffer, uint8_t buffer_length) 
 {
+    if (buffer == NULL || buffer_length == 0) {
+        return 0; // Return 0 for null buffer or zero length
+    }
+
     uint16_t result_checksum = 0;
     uint8_t loop_index = 0;
 

Lab2/test_checksum.c

@@ -34,11 +34,36 @@ void test_calculate_checksum_with_max_values(void) {
     TEST_ASSERT_EQUAL_UINT8(expected_checksum, actual_checksum);
 }
 
+void test_calculate_checksum_with_null_buffer(void) {
+    uint8_t *data = NULL;
+    uint8_t expected_checksum = 0;  // Null buffer should return 0
+    uint8_t actual_checksum = calculate_checksum(data, 10); // Length is arbitrary since buffer is NULL
+    TEST_ASSERT_EQUAL_UINT8(expected_checksum, actual_checksum);
+}
+
+void test_calculate_checksum_with_zero_length(void) {
+    uint8_t data[] = {0x01, 0x02, 0x03};
+    uint8_t expected_checksum = 0;  // Zero length should return 0
+    uint8_t actual_checksum = calculate_checksum(data, 0);
+    TEST_ASSERT_EQUAL_UINT8(expected_checksum, actual_checksum);
+}
+
+void test_calculate_zero_checksum(void) {
+    uint8_t data[] = {0x00, 0x00, 0x00, 0x00};
+    uint8_t expected_checksum = 0;  // All zeros should yield a checksum of 0
+    uint8_t actual_checksum = calculate_checksum(data, sizeof(data));
+    TEST_ASSERT_EQUAL_UINT8(expected_checksum, actual_checksum);
+}
+
 int main(void) {
     UNITY_BEGIN();
     RUN_TEST(test_calculate_checksum_with_valid_data);
     RUN_TEST(test_calculate_checksum_with_empty_data);
     RUN_TEST(test_calculate_checksum_with_max_values);
+    RUN_TEST(test_calculate_checksum_with_null_buffer);
+    RUN_TEST(test_calculate_checksum_with_zero_length);
+    RUN_TEST(test_calculate_zero_checksum);
+
     return UNITY_END();
 }
 

Lab3/Makefile

@@ -0,0 +1,29 @@
+TARGET = Lab3
+CC = arm-none-eabi-gcc
+
+CFLAGS = -mcpu=cortex-m4 -mthumb \
+         -O0 -g \
+         -ffreestanding -fno-builtin\
+         -Isrc -Iunity -Istm32f4 \
+         -Wall -Wextra
+
+LDFLAGS = -T stm32f4/linker.ld \
+          -nostartfiles \
+          -Wl,--gc-sections
+
+SRC = \
+ stm32f4/startup.c \
+ stm32f4/uart.c \
+ src/checksum.c \
+ src/test_checksum.c \
+ src/syscalls.c \
+ unity/unity.c
+
+all:
+	$(CC) $(CFLAGS) $(SRC) $(LDFLAGS) -o $(TARGET).elf
+
+clean:
+	rm -f *.elf
+
+run: all
+	renode --disable-xwt renode/stm32.resc

Lab3/README.MD

@@ -0,0 +1,24 @@
+# Running STM32 Binary on Renode
+* This Lab example uses STM32F4 Discovery kit based example.
+* You can run any firmware built for STM32F407 MCU.
+* Once you build your project, update the below instruction under renode/stm32.resc to load new binary file:
+```
+    sysbus LoadELF @Lab3.elf
+```
+
+# Build and run
+* You can use Makefile in this folder to build and run
+* To Build:
+```sh
+make all
+```
+
+* To run Renode simulator:
+```sh
+make run
+```
+
+* To see Renode GUI terminal for logs and output: 
+```
+renode renode/stm32.resc
+```

Lab3/install_tools.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+sudo apt-get update
+sudo apt-get install -y gcc-arm-none-eabi gdb-multiarch binutils-arm-none-eabi
+
+wget https://github.com/renode/renode/releases/download/v1.16.1/renode_1.16.1_amd64.deb
+sudo dpkg -i renode_1.16.1_amd64.deb
+rm renode_1.16.1_amd64.deb

Lab3/renode/stm32.resc

@@ -0,0 +1,10 @@
+mach create
+machine LoadPlatformDescription @platforms/boards/stm32f4_discovery-kit.repl
+
+sysbus LoadELF @Lab3.elf
+
+showAnalyzer sysbus.usart2
+
+sysbus.usart2 AddLineHook "TEST_RESULT:" "#print 'completed'";quit
+
+start

Lab3/src/checksum.c

@@ -0,0 +1,13 @@
+#include "checksum.h"
+
+uint8_t calculate_checksum(uint8_t *buffer, uint8_t buffer_length) 
+{
+    uint16_t result_checksum = 0;
+    uint8_t loop_index = 0;
+
+    for (loop_index = 0; loop_index < buffer_length; loop_index ++) 
+    {
+        result_checksum += buffer[loop_index ];
+    }
+    return (uint8_t)(result_checksum % 256); 
+}

Lab3/src/checksum.h

@@ -0,0 +1,22 @@
+/**
+ * @file checksum.h
+ * @brief Header file contains the declarations for checksum module
+ * 
+ */
+
+#ifndef CHECKSUM_H
+#define CHECKSUM_H
+
+#include <stdint.h>
+
+/**
+ * @brief Function to calculate the checksum of a given buffer of data. 
+ * The checksum is computed by summing all the bytes in the buffer and taking the result modulo 256.
+ * 
+ * @param buffer Buffer of data for which the checksum is to be calculated.
+ * @param length Length of the buffer.
+ * @return uint8_t The calculated checksum result.
+ */
+uint8_t calculate_checksum(uint8_t *buffer, uint8_t length);
+
+#endif

Lab3/src/syscalls.c

@@ -0,0 +1,58 @@
+#include <sys/stat.h>
+
+/* Stub implementations of system calls for a bare-metal environment.
+    These functions are required by the C library but are not used in this context.
+*/
+int _close(int file)
+{
+    (void)file;
+    return -1;
+}
+
+int _fstat(int file, struct stat *st)
+{
+    (void)file;
+    st->st_mode = S_IFCHR;
+    return 0;
+}
+
+int _isatty(int file)
+{
+    (void)file;
+    return 1;
+}
+
+int _lseek(int file, int ptr, int dir)
+{
+    (void)file;
+    (void)ptr;
+    (void)dir;
+    return 0;
+}
+
+int _read(int file, char *ptr, int len)
+{
+    (void)file;
+    (void)ptr;
+    (void)len;
+    return 0;
+}
+
+int _write(int file, char *ptr, int len)
+{
+    (void)file;
+    (void)ptr;
+    return len;
+}
+
+int _kill(int pid, int sig)
+{
+    (void)pid;
+    (void)sig;
+    return -1;
+}
+
+int _getpid(void)
+{
+    return 1;
+}