Jump to system memory boot from user application

Fixes stm32duino#706

Signed-off-by: Frederic Pillon <[email protected]>

cores/arduino/stm32/backup.h

@@ -59,6 +59,15 @@ extern "C" {
 #endif /* HID_MAGIC_NUMBER_BKP_VALUE */
 #endif /* BL_HID */
 
+#if !defined(SYSBL_MAGIC_NUMBER_BKP_INDEX) && defined(ENABLE_BACKUP_SUPPORT)
+#define SYSBL_MAGIC_NUMBER_BKP_INDEX LL_RTC_BKP_DR2
+#else
+#define SYSBL_MAGIC_NUMBER_BKP_INDEX 0
+#endif /* SYSBL_MAGIC_NUMBER_BKP_INDEX */
+#ifndef SYSBL_MAGIC_NUMBER_BKP_VALUE
+#define SYSBL_MAGIC_NUMBER_BKP_VALUE 0x515B
+#endif /* SYSBL_MAGIC_NUMBER_BKP_VALUE */
+
 /* Exported functions ------------------------------------------------------- */
 static inline void resetBackupDomain(void)
 {

cores/arduino/stm32/bootloader.h

@@ -14,6 +14,12 @@
 extern "C" {
 #endif /* __cplusplus */
 
+/* Request to jump to system memory boot */
+void jumpToBootloaderRequested(void);
+
+/* Jump to system memory boot from user application */
+void jumpToBootloader(void);
+
 #ifdef DTR_TOGGLING_SEQ
 /* DTR toggling sequence management */
 void dtr_togglingHook(uint8_t *buf, uint32_t *len);

cores/arduino/stm32/usb/cdc/usbd_cdc_if.c

@@ -169,6 +169,9 @@ static int8_t USBD_CDC_Control(uint8_t cmd, uint8_t *pbuf, uint16_t length)
       linecoding.format     = pbuf[4];
       linecoding.paritytype = pbuf[5];
       linecoding.datatype   = pbuf[6];
+      if (linecoding.bitrate == 1200) {
+        jumpToBootloaderRequested();
+      }
       break;
 
     case CDC_GET_LINE_CODING:

libraries/SrcWrapper/src/stm32/bootloader.c

@@ -2,7 +2,147 @@
 
 #include "stm32_def.h"
 #include "backup.h"
+#include "stm32yyxx_ll_system.h"
+#include "usbd_if.h"
 
+/*
+ * STM32 built-in bootloader in system memory support
+ */
+/* Private definitions to manage system memory address */
+#define SYSMEM_ADDR_COMMON 0xFFF
+
+typedef struct {
+  uint32_t devID;
+  uint32_t sysMemAddr;
+} devSysMemAddr_str;
+
+devSysMemAddr_str devSysMemAddr[] = {
+#ifdef STM32F0xx
+  {0x440, 0x1FFFEC00},
+  {0x444, 0x1FFFEC00},
+  {0x442, 0x1FFFD800},
+  {0x445, 0x1FFFC400},
+  {0x448, 0x1FFFC800},
+#elif STM32F1xx
+  {0x412, 0x1FFFF000},
+  {0x410, 0x1FFFF000},
+  {0x414, 0x1FFFF000},
+  {0x420, 0x1FFFF000},
+  {0x428, 0x1FFFF000},
+  {0x418, 0x1FFFB000},
+  {0x430, 0x1FFFE000},
+#elif STM32F2xx
+  {0x411, 0x1FFF0000},
+#elif STM32F3xx
+  {SYSMEM_ADDR_COMMON, 0x1FFFD800},
+#elif STM32F4xx
+  {SYSMEM_ADDR_COMMON, 0x1FFF0000},
+#elif STM32F7xx
+  {SYSMEM_ADDR_COMMON, 0x1FF00000},
+#elif STM32G0xx
+  {SYSMEM_ADDR_COMMON, 0x1FFF0000},
+#elif STM32G4xx
+  {SYSMEM_ADDR_COMMON, 0x1FFF0000},
+#elif STM32H7xx
+  {0x450, 0x1FF00000},
+#elif STM32L0xx
+  {SYSMEM_ADDR_COMMON, 0x1FF00000},
+#elif STM32L1xx
+  {SYSMEM_ADDR_COMMON, 0x1FF00000},
+#elif STM32L4xx
+  {SYSMEM_ADDR_COMMON, 0x1FFF0000},
+#elif STM32WBxx
+  {SYSMEM_ADDR_COMMON, 0x1FFF0000},
+#else
+#warning "No system memory address for this serie!"
+#endif
+  {0x0000, 0x00000000}
+};
+
+uint32_t getSysMemAddr(void)
+{
+  uint32_t sysMemAddr = 0;
+  if (devSysMemAddr[0].devID == SYSMEM_ADDR_COMMON) {
+    sysMemAddr = devSysMemAddr[0].sysMemAddr;
+  } else {
+    uint32_t devId = LL_DBGMCU_GetDeviceID();
+    for (uint32_t id = 0; devSysMemAddr[id].devID != 0; id++) {
+      if (devSysMemAddr[id].devID == devId) {
+        sysMemAddr = devSysMemAddr[id].sysMemAddr;
+        break;
+      }
+    }
+  }
+  return sysMemAddr;
+}
+
+/* Request to jump to system memory boot */
+WEAK void jumpToBootloaderRequested(void)
+{
+  enableBackupDomain();
+  setBackupRegister(SYSBL_MAGIC_NUMBER_BKP_INDEX, SYSBL_MAGIC_NUMBER_BKP_VALUE);
+  NVIC_SystemReset();
+}
+
+/* Jump to system memory boot from user application */
+WEAK void jumpToBootloader(void)
+{
+  enableBackupDomain();
+  if (getBackupRegister(SYSBL_MAGIC_NUMBER_BKP_INDEX) == SYSBL_MAGIC_NUMBER_BKP_VALUE) {
+    setBackupRegister(SYSBL_MAGIC_NUMBER_BKP_INDEX, 0);
+
+#ifdef USBCON
+    USBD_reenumerate();
+#endif
+    void (*sysMemBootJump)(void);
+
+    /**
+     * Get system memory address
+     *
+     * Available in AN2606 document:
+     * Table xxx Bootloader device-dependent parameters
+     */
+    volatile uint32_t sysMem_addr = getSysMemAddr();
+    /*
+     * If the system address is not not referenced in 'devSysMemAddr' array,
+     * does not do anything
+     */
+    if (sysMem_addr != 0) {
+#ifdef __HAL_SYSCFG_REMAPMEMORY_SYSTEMFLASH
+      /* Remap system Flash memory at address 0x00000000 */
+      __HAL_SYSCFG_REMAPMEMORY_SYSTEMFLASH();
+#endif
+
+      /**
+       * Set jump memory location for system memory
+       * Use address with 4 bytes offset which specifies jump location
+       * where program starts
+       */
+      sysMemBootJump = (void (*)(void))(*((uint32_t *)(sysMem_addr + 4)));
+
+      /**
+       * Set main stack pointer.
+       * This step must be done last otherwise local variables in this function
+       * don't have proper value since stack pointer is located on different position
+       *
+       * Set direct address location which specifies stack pointer in SRAM location
+       */
+      __set_MSP(*(uint32_t *)sysMem_addr);
+
+      /**
+       * Jump to set location
+       * This will start system memory execution
+       */
+      sysMemBootJump();
+
+      while (1);
+    }
+  }
+}
+
+/*
+ * Legacy maple bootloader support
+ */
 #ifdef BL_LEGACY_LEAF
 void dtr_togglingHook(uint8_t *buf, uint32_t *len)
 {
@@ -17,6 +157,9 @@ void dtr_togglingHook(uint8_t *buf, uint32_t *len)
 }
 #endif /* BL_LEGACY_LEAF */
 
+/*
+ * HID bootloader support
+ */
 #ifdef BL_HID
 void dtr_togglingHook(uint8_t *buf, uint32_t *len)
 {

libraries/SrcWrapper/src/stm32/hw_config.c

@@ -35,10 +35,11 @@
   *
   ******************************************************************************
   */
-#include "stm32_def.h"
+#include "bootloader.h"
+#include "dwt.h"
 #include "hw_config.h"
 #include "usbd_if.h"
-#include "dwt.h"
+#include "stm32_def.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -59,6 +60,9 @@ void hw_config_init(void)
   /* Initialize the HAL */
   HAL_Init();
 
+  /* Check if a jump to system memory boot requested */
+  jumpToBootloader();
+
   /* Configure the system clock */
   SystemClock_Config();