CC2642 OAD#

1. 基本信息#

  • BLE 5.2
  • Powerful 48-MHz Arm® Cortex®-M4 processor
  • 352KB flash program memory
  • 256KB of ROM for protocols and library functions
  • 8KB of cache SRAM
  • 80KB of ultra-low leakage SRAM with parity for high-reliability operation

  • 2-pin cJTAG and JTAG debugging（不支持SWD接口），比较新的JLINK应该是支持cJTAG接口的

  • 重要！请阅读：BLE Enhanced (OAD) Fundamentals

2. OAD(Over tO Air Download)存储布局#

具有OAD功能的BLE程序，其Flash布局由三部分组成：

  • BIM + CCFG
  • persistent app + Stack，persistent_app是永久存储在Flash上的（相对于OAD可升级而言），其的作用是完成应用程序的升级（类似于MCU中常说的自定义升级BootLoader）
  • User app + Stack，User app是用户程序，也就是OAD升级的目标

2.1 BIM(Boot Image Manager) & CCFG#

这部分大小是固定的。

2.2 OAD_IMG_A(persistent_app 的起始地址)#

  • OAD_IMG_A ~ (DEVICE_SIZE-BIM_SIZE)这块Flash区域就是用来存放 persistent_app 的，persistent_app是永久存储在Flash上的（相对于OAD可升级而言），其的作用是完成应用程序的升级（类似于MCU中常说的自定义升级BootLoader）
  • OAD_IMG_A 是Persistent application的起始地址，该地址的实际值需要根据具体的应用来决定，通过连接脚本中Flash的划分来决定；
  • HDR_START是连接脚本中的变量名
  • 我们可以参看下Demo工程中的连接脚本：simplelink_cc13xx_cc26xx_sdk_6_20_00_29\examples\rtos\CC26X2R1_LAUNCHXL\ble5stack\persistent_app\\tirtos7\ticlang\cc13x2_cc26x2_app_tirtos7.cmd
...

#define FLASH_BASE   0x00000000
#define GPRAM_BASE   0x11000000
#define RAM_BASE     0x20000000
#define ROM_BASE     0x10000000

#define FLASH_SIZE   0x00058000
#define GPRAM_SIZE   0x00002000
#define RAM_SIZE     0x00014000
#define ROM_SIZE     0x00040000


#define NUM_RESERVED_FLASH_PAGES   1
#define RESERVED_FLASH_SIZE        (NUM_RESERVED_FLASH_PAGES * PAGE_SIZE)


#define IMG_A_FLASH_START          0x00038000  // 224K

/* Image specific addresses */
#ifdef OAD_IMG_A
  #define  OAD_HDR_START           IMG_A_FLASH_START  // 224K ↑
  #define  OAD_HDR_END             (OAD_HDR_START + OAD_HDR_SIZE - 1)
  #define  ENTRY_SIZE              0x40
  #define  ENTRY_START             (OAD_HDR_END + 1)
  #define  ENTRY_END               ENTRY_START + ENTRY_SIZE - 1
  #define  FLASH_START             (ENTRY_END + 1)
  #define  FLASH_END               (FLASH_BASE + FLASH_SIZE - RESERVED_FLASH_SIZE - 1)
#else
  #define OAD_HDR_START            FLASH_BASE
  #define OAD_HDR_END              (OAD_HDR_START + OAD_HDR_SIZE - 1)

  #define ENTRY_START              (OAD_HDR_END + 1)
  #define ENTRY_SIZE               0x40
  #define ENTRY_END                ENTRY_START + ENTRY_SIZE - 1
  #define FLASH_START              (ENTRY_END + 1)
  #define FLASH_END                (FLASH_BASE + IMG_A_FLASH_START - 1)
#endif

...
  • 从上面的链接脚本中的#define IMG_A_FLASH_START 0x00038000 // 224K 可以得知Persistent App的烧写地址是0x38000

2.3 OAD_IMG_B（User App 的结束地址）#

  • 0x00 ~ (OAD_IMG_A-1)这块Flash区域就是用来存储用户程序的，也就是OAD升级的目标
  • OAD_IMG_B是用户程序的结束地址，这个地址也是可变的，程序大就往上，程序小就往下
  • Avaliable User Application Space应该就是指OAD_IMG_B是可变的，所以这部分可能用得上，也可能是空置的，最大就是到OAD_IMG_A，
  • FLASH_END是连接脚本中的变量名称
  • 其连接脚本请参考simplelink_cc13xx_cc26xx_sdk_6_20_00_29\examples\rtos\CC26X2R1_LAUNCHXL\ble5stack\simple_peripheral_oad_onchip\tirtos7\ticlang\cc13x2_cc26x2_app_tirtos7.cmd

3. OAD升级试验#

  • 重要！！！参考：

  • persistent_app工程（烧写地址0x38000，该地址源于工程的链接脚本）和simple_peripheral_oad_onchip工程默认是使能OAD安全的，所以BIM也选择安全的版本

  • OAD Distributor使用BTool（simplelink_cc13xx_cc26xx_sdk_6_20_00_29\tools\ble5stack\btool）+CC2642板子（TI BLE5-Stack Quick Start文档中介绍的 TI SimpleLink Starter app实测不能用）

  • OAD Target使用另一块CC2642板子

4. Adding BLE OAD to an Existing Project#

4.1 Setting up the BLE OAD Environment#

  • 参考链接：simplelink_cc13xx_cc26xx_sdk_6_20_00_29/docs/ble5stack/ble_user_guide/html/ble-stack-oad/setting-up-environment.html

  • OAD Settings in SysConfig

  • RF STACKS -> BLE -> Advanced Settings -> OAD Only Defines
OAD Define Function
LED_DEBUG Blink LEDs for different states in App, BIM and Persistent App (on-chip only).
OAD_DEBUG Enable/Disable debugging feature for external flash via UART for off-chip OAD applications (refer to oad_efl_dbg.h for details).
FEATURE_OAD Required for OAD functionality.
OAD_BLE_SECURITY Not to be confused with secure/non-secure OAD (refer to OAD Security). If defined in the user / persistent (for onchip OAD) application project, The OAD distributor will be forced to be paired with the OAD target in order for the OAD to happen. 根据TI文档Adding BLE OAD to an Existing Project中的描述，OAD安全是在Build->Arm Compiler->Predefined Symbols和Build->Arm Libker->Advanced Options->Command File Preprocessing中都有定义
  • 如上在SysConfig中的定义最终会生成在Generate Source/SysConfig/ti_ble_app_config.opt文件中
ti_ble_app_config.opt

-DLED_DEBUG
-DOAD_DEBUG
-DFEATURE_OAD
  • 所以在SysConfig中的定义应该是等同于在Build->Arm Compiler->Predefined Symbols中的定义

4.2 生成新的OAD密钥对#

  • 重要！！！参考： simplelink_cc13xx_cc26xx_sdk_6_20_00_29/docs/ble5stack/ble_user_guide/html/oad-secure/tools.html#generating-new-security-keys-embedded

  • 如果使用较高版本的Python（应该是Python3.9及以上），那么在执行密钥对生成脚本的时候，会报错：AttributeError: 'array.array' object has no attribute 'tostring'，这是因为在Python3.9中将array.array: tostring()移除了，具体参考：https://github.com/googlesamples/assistant-sdk-python/issues/418，我们将脚本中的a.tostring()和b.tostring()改成a.tobytes()和a.tobytes()就可以了

  • 成功运行key_generate.py后将会生成新的密钥对和key_info.txt，要将公钥设置到BIM工程，用户程序编译时会使用私钥加密，然后CC2642启动时BIM会使用事先设置的公钥对用户程序镜像进行验证

key_info.txt

Private key: b'f2d482df2700f3c1eb0dcae7957611180001f1b0c33dc07cee8b5d31cfee4791'
Public Key b'70e196af6028241814e5017edc4d329c0204f04a9b2d87dbfcf6955b865d76aa595b29d2f388c7cf222ef941aff0efa6698db5d2122a739c1db5a4063097461b'
Public key X: b' 70 e1 96 af 60 28 24 18 14 e5 01 7e dc 4d 32 9c 02 04 f0 4a 9b 2d 87 db fc f6 95 5b 86 5d 76 aa '
Public key Y : b' 59 5b 29 d2 f3 88 c7 cf 22 2e f9 41 af f0 ef a6 69 8d b5 d2 12 2a 73 9c 1d b5 a4 06 30 97 46 1b '
Public key X in reversed format : b'aa765d865b95f6fcdb872d9b4af004029c324ddc7e01e51418242860af96e170'
Public key Y in reversed format: b'1b46973006a4b51d9c732a12d2b58d69a6eff0af41f92e22cfc788f3d2295b59'
Signer Info: 88 0b 8a c8 c4 1b a1 4f
  • 将key_info.txt中的Signer Info, Public key X,Public key Y对应写入BIM工程即可
// bim_onchip/Application/bim_onchip_main.c

{
  .version    = SECURE_SIGN_TYPE,
  .len        = SECURE_CERT_LENGTH,
  .options    = SECURE_CERT_OPTIONS,
  .signerInfo = {0xb0,0x17,0x7d,0x51,0x1d,0xec,0x10,0x8b},
  .certPayload.eccKey.pubKeyX = {0xd8,0x51,0xbc,0xa2,0xed,0x3d,0x9e,0x19,0xb7,0x33,0xa5,0x2f,0x33,0xda,0x05,0x40,0x4d,0x13,0x76,0x50,0x3d,0x88,0xdf,0x5c,0xd0,0xe2,0xf2,0x58,0x30,0x53,0xc4,0x2a},
  .certPayload.eccKey.pubKeyY = {0xb9,0x2a,0xbe,0xef,0x66,0x5f,0xec,0xcf,0x56,0x16,0xcc,0x36,0xef,0x2d,0xc9,0x5e,0x46,0x2b,0x7c,0x3b,0x09,0xc1,0x99,0x56,0xd9,0xaf,0x95,0x81,0x63,0x23,0x7b,0xe7}
 };