Remove ST CRC library but keep using hardware-accelerated CRC32.

Add integrity check of the vector table.

Signed-off-by: Marcos Chaparro <[email protected]>

ChibiOS_3.0.2/ext/stdperiph_stm32f4/stm32lib.mk

@@ -8,7 +8,6 @@ STM32SRC = 	${CHIBIOS}/ext/stdperiph_stm32f4/src/misc.c \
 			${CHIBIOS}/ext/stdperiph_stm32f4/src/stm32f4xx_syscfg.c \
 			${CHIBIOS}/ext/stdperiph_stm32f4/src/stm32f4xx_tim.c \
 			${CHIBIOS}/ext/stdperiph_stm32f4/src/stm32f4xx_iwdg.c \
-			${CHIBIOS}/ext/stdperiph_stm32f4/src/stm32f4xx_crc.c \
 			${CHIBIOS}/ext/stdperiph_stm32f4/src/stm32f4xx_wwdg.c
 
 STM32INC = ${CHIBIOS}/ext/stdperiph_stm32f4/inc

crc.c

@@ -18,6 +18,7 @@
     */
 
 #include "crc.h"
+#include "stm32f4xx.h"
 
 // CRC Table
 const unsigned short crc16_tab[] = { 0x0000, 0x1021, 0x2042, 0x3063, 0x4084,
@@ -58,3 +59,29 @@ unsigned short crc16(unsigned char *buf, unsigned int len) {
 	}
 	return cksum;
 }
+
+/**
+  * @brief  Computes the 32-bit CRC of a given buffer of data word(32-bit) using
+  * Hardware Acceleration.
+  * @param  pBuffer: pointer to the buffer containing the data to be computed
+  * @param  BufferLength: length of the buffer to be computed
+  * @retval 32-bit CRC
+  */
+uint32_t crc32(uint32_t *pBuffer, uint32_t BufferLength) {
+  uint32_t index = 0;
+
+  for(index = 0; index < BufferLength; index++) {
+    CRC->DR = pBuffer[index];
+  }
+  return (CRC->DR);
+}
+
+/**
+  * @brief  Resets the CRC Data register (DR).
+  * @param  None
+  * @retval None
+  */
+void crc32_reset(void) {
+  /* Reset CRC generator */
+  CRC->CR = CRC_CR_RESET;
+}

crc.h

@@ -20,9 +20,13 @@
 #ifndef CRC_H_
 #define CRC_H_
 
+#include <stdint.h>
+
 /*
  * Functions
  */
 unsigned short crc16(unsigned char *buf, unsigned int len);
+uint32_t crc32(uint32_t *buf, uint32_t len);
+void crc32_reset(void);
 
 #endif /* CRC_H_ */

flash_helper.c

@@ -21,11 +21,11 @@
 #include "ch.h"
 #include "hal.h"
 #include "stm32f4xx_conf.h"
-#include "stm32f4xx_crc.h"
 #include "utils.h"
 #include "mc_interface.h"
 #include "timeout.h"
 #include "hw.h"
+#include "crc.h"
 #include <string.h>
 
 /*
@@ -56,6 +56,12 @@
 #define	APP_CRC_WAS_CALCULATED_FLAG			((uint32_t)0xAAAAAAAA)
 #define	APP_CRC_WAS_CALCULATED_FLAG_ADDRESS	(uint32_t*)(APP_MAX_SIZE - 8)
 
+#define VECTOR_TABLE_ADDRESS	(uint32_t *)ADDR_FLASH_SECTOR_0
+#define VECTOR_TABLE_SIZE		(ADDR_FLASH_SECTOR_1 - ADDR_FLASH_SECTOR_0)
+
+#define APP_START_ADDRESS		(uint32_t *)(ADDR_FLASH_SECTOR_1 + EEPROM_EMULATION_SIZE)
+#define APP_SIZE				(APP_MAX_SIZE - VECTOR_TABLE_SIZE - EEPROM_EMULATION_SIZE)
+
 // Private constants
 static const uint32_t flash_addr[FLASH_SECTORS] = {
 		ADDR_FLASH_SECTOR_0,
@@ -214,15 +220,19 @@ uint32_t flash_helper_verify_flash_memory(void) {
 	if( (APP_CRC_WAS_CALCULATED_FLAG_ADDRESS)[0] == APP_CRC_WAS_CALCULATED_FLAG )
     {
 		RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, ENABLE);
-		CRC_ResetDR();
+		crc32_reset();
+
+		// compute vector table (sector 0)
+		crc32((VECTOR_TABLE_ADDRESS), (VECTOR_TABLE_SIZE)/4);
+
+		// skip emulated EEPROM (sector 1 and 2)
 
-		// A CRC over the full image should return zero. Exclude the pages used for
-		// storing user configuration data.
-		crc= CRC_CalcBlockCRC((uint32_t*)(	ADDR_FLASH_SECTOR_0 + EEPROM_EMULATION_SIZE),
-							  (APP_MAX_SIZE - EEPROM_EMULATION_SIZE)/4);
+		// compute application code
+		crc = crc32(APP_START_ADDRESS, (APP_SIZE)/4);
 
 		RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, DISABLE);
 
+		// A CRC over the full image should return zero.
 		return (crc == 0)? FAULT_CODE_NONE : FAULT_CODE_FLASH_CORRUPTION;
     }
 	else {
@@ -239,9 +249,16 @@ uint32_t flash_helper_verify_flash_memory(void) {
 
    		// Compute flash crc including the new flag
 		RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, ENABLE);
-		CRC_ResetDR();
-		crc= CRC_CalcBlockCRC((uint32_t*)(ADDR_FLASH_SECTOR_0 + EEPROM_EMULATION_SIZE),
-							  (APP_MAX_SIZE - EEPROM_EMULATION_SIZE - 4)/4);
+		crc32_reset();
+
+		// compute vector table (sector 0)
+		crc32(VECTOR_TABLE_ADDRESS, (VECTOR_TABLE_SIZE)/4);
+
+		// skip emulated EEPROM (sector 1 and 2)
+
+		// compute application code
+		crc = crc32(APP_START_ADDRESS, (APP_SIZE - 4)/4);
+
 		RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_CRC, DISABLE);
 
 		//Store CRC