[参考译文] TM4C1297NCZAD：将 TM4C1297nczadi3用作 USB 主机-通过从 USB 存储器读取二进制文件进行固件更新

客户电路板具有 TM4C1297NCZADI3微控制器。 此客户电路板具有一个 USB Type-A 母连接器。

1. 我是否可以C:\ti\TivaWare_C_Series-2.2.0.295\examples\boards\ek-tm4c1294xl\usb_stick_update针对此特定微控制器 TM4C1297NCZADI3实施中的示例、是否有其他类型的电路板、如 dk-tm4c129x、ek-tm4c129exl 和 ek-tm4c1294xl？  以下哪个示例与该客户电路板上的该微控制器更兼容？

   #define PROG_LEN (FLASH_SIZE - 0x20000) 
   #define DATA_LEN  0x2000
   #define USB_STICK_UPDATE_ADDRESS      0x00000000  //USB stick update
   #define APP_START_ADDRESS             0x8000      //My Application
   
   MEMORY
   {
       /* Application stored in and executes from internal flash */
       PROG_FLASH (RX) : origin = APP_START_ADDRESS, length = PROG_LEN
   
       DATA_FLASH (RWX) : origin = USB_STICK_UPDATE_ADDRESS, length = DATA_LEN
       /* Application uses internal RAM for data */
       SRAM (RWX) : origin = 0x20000000, length = 0x00060000 /*0x00040000*/
   }
   
   /* Section allocation in memory */
   
   SECTIONS
   {
       .intvecs:   > APP_BASE
       .text   :   > PROG_FLASH
       .const  :   > PROG_FLASH
       .cinit  :   > PROG_FLASH
       .pinit  :   > PROG_FLASH
       .binit	:	> PROG_FLASH
       .init_array : > PROG_FLASH
   
       .vtable :   > RAM_BASE
       .data   :   > SRAM
       .bss    :   > SRAM
       .sysmem :   > SRAM
       .stack  :   > SRAM
       .TI.ramfunc : {} load=PROG_FLASH, run=SRAM, table(BINIT)
   }

2. 是否有必要APP_START_ADDRESS如代码中所示修改0x8000？

3. 客户电路板具有用于 USB 的引脚：USB0DP、USB0DM、USB0VBUS、但 USB0ID (已断开连接)。 我怀疑如果断开连接、我是否可以使用 USB0ID。 我能在内部控制它吗？ 我使用 USB 的目的是通过 USB Type-A 记忆棒更新固件、因此我知道应该将其配置为主机。 能否向我提供一个示例、说明我如何执行该操作？  

此外、我看到  USB 器件的数据表不完整。 这里没有关于如何配置寄存器的信息。 在哪里可以找到 Tiva TM4C1297NCZAD 微控制器的 USB 信息？

您好！

如果您使用的定制电路板上有 TM4C1297NCZAD、则可以参考  TivaWare_C_Series-2.2.0.295\examples\boards\dk-tm4c129x\usb_tick_update。 请注意、usb_stick_update 更像是位于0x0的引导加载程序。 您无需修改 USB_STICK_UPDATE 的.cmd 文件。 APP_BASE 在.cmd 文件中将为0x00000000。 您需要指定应用程序固件在引导加载程序源代码中的位置。 查看第120行的 usb_stick_update.c 文件、其中假设#define APP_START_ADDRESS 等于0x8000。 您可以将该地址修改为1024字节的倍数的其他地址。 引导加载程序(USB_STICK_DATE)本身必须位于0x0。   

请不要混淆已在 usb_stick_updart.cmd 文件中的 app_BASE 和在 usb_stick_updarte.c 文件中的 app_start_address。  

• 是否有必要APP_START_ADDRESS如代码中所示修改0x8000？

您还需要使用应用程序固件。 如我所述、有一个示例应用 、位于 C：\ti\TivaWare_C_Series-2.2.0.295\examples\boards\dk-tm4c129x\usb_tick_demo。 查看 C：\ti\TivaWare_C_Series-2.2.0.295\examples\boards\dk-tm4c129x\usb_stick_demo\usb_tick_demo_ccs.cmd 内的命令文件。 APP_BASE 设置为0x8000的就是该文件。 请参阅下面的片段。

/* The starting address of the application. Normally the interrupt vectors */
/* must be located at the beginning of the application. */
#define APP_BASE 0x00008000
#define RAM_BASE 0x20000000

/* System memory map */

MEMORY
{
/* Application stored in and executes from internal flash */
FLASH (RX) : origin = APP_BASE, length = 0x000f8000
/* Application uses internal RAM for data */
SRAM (RWX) : origin = 0x20000000, length = 0x00040000
}

1. 客户电路板具有用于 USB 的引脚：USB0DP、USB0DM、USB0VBUS、但 USB0ID (已断开连接)。 我怀疑如果断开连接、我是否可以使用 USB0ID。 我能在内部控制它吗？ 我使用 USB 的目的是通过 USB Type-A 记忆棒更新固件、因此我知道应该将其配置为主机。 能否向我提供一个示例、说明我如何执行该操作？  

我觉得不需要 VBUSID 来运行 usb_stick_update。

只是想告诉你、我在 DK-TM4C129x 板上运行 usb_stick_update、下载成功加载 usb_stick_demo 程序。 如果您有 DK 板、我建议您按原样运行它以获得使用体验。 如果您没有 DK 板、这就是为什么我首先建议您通过运行  C：\ti\TivaWare_C_Series-2.2.0.295\examples\boards\ek-tm4c1294xl\usb_tick_update 在 EK-TM4C1294XL LaunchPad 板上运行的原因。

尊敬的 Charles：

想知道 USB 更新程序是否具有闪存擦除功能、或者用户是否必须在每次需要更新时手动擦除闪存组？  

您好、BP101：

 是的、更新程序具有闪存擦除/编程功能。 请参阅以下 usb_stick_update.c 文件中的函数。  

//*****************************************************************************
//
// Read the application image from the file system and program it into flash.
//
// This function will attempt to open and read the firmware image file from
// the mass storage device.  If the file is found it will be programmed into
// flash.  The name of the file to be read is configured by the macro
// \b USB_UPDATE_FILENAME.  It will be programmed into flash starting at the
// address specified by APP_START_ADDRESS.
//
// \return Zero if successful or non-zero if the file cannot be read or
// programmed.
//
//*****************************************************************************
uint32_t
ReadAppAndProgram(void)
{
    uint_fast32_t ui32FlashEnd;
    uint_fast32_t ui32FileSize;
    uint_fast32_t ui32DataSize;
    uint_fast32_t ui32Remaining;
    uint_fast32_t ui32ProgAddr;
    uint_fast32_t ui32SavedRegs[2];
    volatile uint_fast32_t ui32Idx;
    uint_fast32_t ui32DriveTimeout;

    //
    // Initialize the drive timeout.
    //
    ui32DriveTimeout = USBMSC_DRIVE_RETRY;

    //
    // Check to see if the mass storage device is ready.  Some large drives
    // take a while to be ready, so retry until they are ready.
    //
    while(USBHMSCDriveReady(g_psMSCInstance))
    {
        //
        // Wait about 500ms before attempting to check if the
        // device is ready again.
        //
        SysCtlDelay(g_ui32SysClock/(3*2));

        //
        // Decrement the retry count.
        //
        ui32DriveTimeout--;

        //
        // If the timeout is hit then return with a failure.
        //
        if(ui32DriveTimeout == 0)
        {
            return(1);
        }
    }

    //
    // Initialize the file system and return if error.
    //
    if(SimpleFsInit(g_ui8SectorBuf))
    {
        return(1);
    }

    //
    // Attempt to open the firmware file, retrieving the file/image size.
    // A file size of error means the file was not there, or there was an
    // error.
    //
    ui32FileSize = SimpleFsOpen(USB_UPDATE_FILENAME);
    if(ui32FileSize == 0)
    {
        return(1);
    }

    //
    // Get the size of flash.  This is the ending address of the flash.
    // If reserved space is configured, then the ending address is reduced
    // by the amount of the reserved block.
    //
    ui32FlashEnd = FLASH_SIZE;
#ifdef FLASH_RSVD_SPACE
    ui32FlashEnd -= FLASH_RSVD_SPACE;
#endif

    //
    // If flash code protection is not used, then change the ending address
    // to be the ending of the application image.  This will be the highest
    // flash page that will be erased and so only the necessary pages will
    // be erased.  If flash code protection is enabled, then all of the
    // application area pages will be erased.
    //
#ifndef FLASH_CODE_PROTECTION
    ui32FlashEnd = ui32FileSize + APP_START_ADDRESS;
#endif

    //
    // Check to make sure the file size is not too large to fit in the flash.
    // If it is too large, then return an error.
    //
    if((ui32FileSize + APP_START_ADDRESS) > ui32FlashEnd)
    {
        return(1);
    }

    //
    // Enter a loop to erase all the requested flash pages beginning at the
    // application start address (above the USB stick updater).
    //
    for(ui32Idx = APP_START_ADDRESS; ui32Idx < ui32FlashEnd; ui32Idx += 1024)
    {
        ROM_FlashErase(ui32Idx);
    }

    //
    // Enter a loop to read sectors from the application image file and
    // program into flash.  Start at the user app start address (above the USB
    // stick updater).
    //
    ui32ProgAddr = APP_START_ADDRESS;
    ui32Remaining = ui32FileSize;
    while(SimpleFsReadFileSector())
    {
        //
        // Compute how much data was read from this sector and adjust the
        // remaining amount.
        //
        ui32DataSize = ui32Remaining >= 512 ? 512 : ui32Remaining;
        ui32Remaining -= ui32DataSize;

        //
        // Special handling for the first block of the application.
        // This block contains as the first two location the application's
        // initial stack pointer and instruction pointer.  The USB updater
        // relied on the values in these locations to determine if a valid
        // application is present.  When there is a valid application the
        // updater runs the user application.  Otherwise the updater attempts
        // to load a new application.
        // In order to prevent a partially programmed imaged (due to some
        // error occurring while programming), the first two locations are
        // not programmed until all of the rest of the image has been
        // successfully loaded into the flash.  This way if there is some error,
        // the updater will detect that a user application is not present and
        // will not attempt to run it.
        //
        // For the first block, do not program the first two word locations
        // (8 bytes).  These two words will be programmed later, after
        // everything else.
        //
        if(ui32ProgAddr == APP_START_ADDRESS)
        {
            uint32_t *pui32Temp;

            pui32Temp = (uint32_t *)g_ui8SectorBuf;
            ui32SavedRegs[0] = pui32Temp[0];
            ui32SavedRegs[1] = pui32Temp[1];

            //
            // Call the function to program a block of flash.  Skip the first
            // two words (8 bytes) since these contain the initial SP and PC.
            //
            ROM_FlashProgram((uint32_t *)&g_ui8SectorBuf[8],
                             ui32ProgAddr + 8,
                             ((ui32DataSize - 8) + 3) & ~3);
        }

        //
        // All other blocks except the first block
        //
        else
        {
            //
            // Call the function to program a block of flash.  The length of the
            // block passed to the flash function must be divisible by 4.
            //
            ROM_FlashProgram((uint32_t *)g_ui8SectorBuf, ui32ProgAddr,
                             (ui32DataSize + 3) & ~3);
        }

        //
        // If there is more image to program, then update the programming
        // address.  Progress will continue to the next iteration of
        // the while loop.
        //
        if(ui32Remaining)
        {
            ui32ProgAddr += ui32DataSize;
        }

        //
        // Otherwise we are done programming so perform final steps.
        // Program the first two words of the image that were saved earlier,
        // and return a success indication.
        //
        else
        {
            ROM_FlashProgram((uint32_t *)ui32SavedRegs, APP_START_ADDRESS,
                              8);

            return(0);
        }
    }

    //
    // If we make it here, that means that an attempt to read a sector of
    // data from the device was not successful.  That means that the complete
    // user app has not been programmed into flash, so just return an error
    // indication.
    //
    return(1);
}