Second commit for crc32

libraries/ms-common/inc/crc32.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "FreeRTOS.h"
+#include "status.h"
+
+// Initialize CRC calculation (no use for STM32F1)
+StatusCode crc_init(void);
+
+// Calculate CRC32 for an entire buffer
+uint32_t crc_calculate(const uint32_t *buffer, size_t buffer_len);

libraries/ms-common/src/arm/crc32.c

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+#include "crc32.h" // Include the header file for CRC32 function declarations
+
+#include "log.h" // Include the logging utility, possibly used for debugging or status messages
+#include "misc.h"
+#include "stm32f10x.h" // Include the STM32F1 series specific header file for hardware definitions
+#include "stm32f10x_crc.h" // Include the CRC library header
+
+// Initialization function for CRC
+StatusCode crc_init(void) {
+ // Enable the CRC peripheral clock
+ RCC->AHBENR |= RCC_AHBENR_CRCEN;
+
+ // Reset CRC Data Register
+ CRC_ResetDR();
+
+ return STATUS_CODE_OK; // Return OK status
+}
+
+// Function to calculate CRC32 for a given buffer, with an option to append to an existing CRC
+uint32_t crc_calculate(const uint32_t *buffer, size_t buffer_len) {
+ CRC_ResetDR(); // Reset the CRC Data Register
+
+ // Process each byte in the buffer
+ for (size_t i = 0; i < buffer_len; i++) {
+ CRC_CalcCRC(buffer[i]); // Calculate CRC for each byte
+ }
+
+ return ~CRC_GetCRC(); // Return the inverted final CRC value
+}

libraries/ms-common/src/x86/crc32.c

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+#include "crc32.h" // Include the header file for CRC32 function declarations
+
+#include "log.h" // Include the logging utility, possibly used for debugging or status messages
+#include "misc.h"
+#include "stm32f10x.h" // Include the STM32F1 series specific header file for hardware definitions
+#include "stm32f10x_crc.h" // Include the CRC library header
+
+// Define the CRC32 polynomial and initial value
+#define CRC32_POLYNOMIAL \
+ 0x04C11DB7 // Standard CRC32 polynomial (used in many protocols and formats)
+#define CRC32_INIT_VALUE 0xFFFFFFFF // Initial value used to start the CRC calculation
+
+static uint32_t crc32_calculate_byte(uint32_t crc, uint32_t data) {
+ crc ^= data; // XOR the word directly into the CRC value
+
+ // Perform the polynomial division one bit at a time for each of the 32 bits
+ for (int i = 0; i < 32; i++) {
+ if (crc & 0x80000000) { // If the top bit is set (MSB is 1)
+ crc = (crc << 1) ^ CRC32_POLYNOMIAL; // Shift left and XOR with the polynomial
+ } else {
+ crc <<= 1; // Just shift left if the top bit is not set
+ }
+ }
+ return crc; // Return the updated CRC value after processing the word
+}
+
+uint32_t crc_calculate(const uint32_t *buffer, size_t buffer_len) {
+ uint32_t crc = ~0; // Initialize CRC with the inverted initial value (standard practice)
+
+ // Process each byte in the buffer
+ for (size_t i = 0; i < buffer_len; i++) {
+ crc = crc32_calculate_byte(crc, buffer[i]); // Update CRC for each byte
+ }
+
+ return ~crc; // Return the inverted CRC32 value (final CRC value needs to be inverted)
+}
+
+// no use for x86
+StatusCode crc_init(void) {
+ return STATUS_CODE_OK;
+}