【单片机开发】stm32f429在线IAP 实现SD卡烧写程序

（一）背景介绍

最近做了一个工程需要用到IAP在线升级这个功能，当时在学的时候，了解到IAP的功能当时就觉得很鸡肋，明明有烧写器干嘛那么费事，现在觉得当时确实浅薄了，IAP功能在工程中确实是非常有用的，他可以让你的嵌入式产品可以像手机一样实现在线升级，添加APP，没有必要每次都把外壳拆下来进行烧写。更关键的是，这次在学习IAP的过程中我之前很多不理解的东西，忽然就搞明白了。因为这段时间我也在学LINUX对于嵌入式LINUX的开发方式是非常不习惯的，毕竟集成IDE也用惯了吗，可是在这次后，我忽然发现，IAP的开发方式和传统的脱离IDE的LINUX开发方式是相同的，都是先烧写bootload,LINUX里面叫uboot,顿时我就不淡定了。之前一直用集成IDE心理总会是有一点不踏实的，感觉自己被人家安排了，不管你这么些代码也没有跳出那些条条框框，现在就舒服了吗。

（二）boot移植修改

在移植过程中也遇到了很多坑，好在都解决了。现在把关键的地方都记录一下，感觉以后肯定还会再用到。
我是采用正点原子的FATFS实验直接进行的移植。正点原子也有IAP升级历程但是是串口升级，搭配蓝牙或者无线模块可以进行远程升级。我这里因为工程需要采用SD卡升级的方式。
移植中主要就是对程序的剪裁，毕竟是BOOTLOAD程序你搞个几百K显然不合适啦。我们要删去LCD,LTDC驱动，加入内存管理，SD卡，文件管理等功能。并且剪裁FATFS减少数据量。

关键在于ffconf.h文件的修改。
修改如下。

/*---------------------------------------------------------------------------/
/  FatFs - FAT file system module configuration file  R0.12  (C)ChaN, 2016
/---------------------------------------------------------------------------*/#define _FFCONF 88100 /* Revision ID *//*---------------------------------------------------------------------------/
/ Function Configurations
/---------------------------------------------------------------------------*/#define _FS_READONLY  0
/* This option switches read-only configuration. (0:Read/Write or 1:Read-only)
/  Read-only configuration removes writing API functions, f_write(), f_sync(),
/  f_unlink(), f_mkdir(), f_chmod(), f_rename(), f_truncate(), f_getfree()
/  and optional writing functions as well. */#define _FS_MINIMIZE   0
/* This option defines minimization level to remove some basic API functions.
/
/   0: All basic functions are enabled.
/   1: f_stat(), f_getfree(), f_unlink(), f_mkdir(), f_truncate() and f_rename()
/      are removed.
/   2: f_opendir(), f_readdir() and f_closedir() are removed in addition to 1.
/   3: f_lseek() function is removed in addition to 2. */#define    _USE_STRFUNC    1
/* This option switches string functions, f_gets(), f_putc(), f_puts() and
/  f_printf().
/
/  0: Disable string functions.
/  1: Enable without LF-CRLF conversion.
/  2: Enable with LF-CRLF conversion. */#define _USE_FIND       0
/* This option switches filtered directory read functions, f_findfirst() and
/  f_findnext(). (0:Disable, 1:Enable 2:Enable with matching altname[] too) */#define   _USE_MKFS       1
/* This option switches f_mkfs() function. (0:Disable or 1:Enable) */#define    _USE_FASTSEEK   1
/* This option switches fast seek function. (0:Disable or 1:Enable) */#define   _USE_EXPAND     0
/* This option switches f_expand function. (0:Disable or 1:Enable) */#define _USE_CHMOD     0
/* This option switches attribute manipulation functions, f_chmod() and f_utime().
/  (0:Disable or 1:Enable) Also _FS_READONLY needs to be 0 to enable this option. */#define _USE_LABEL      1
/* This option switches volume label functions, f_getlabel() and f_setlabel().
/  (0:Disable or 1:Enable) */#define    _USE_FORWARD    0
/* This option switches f_forward() function. (0:Disable or 1:Enable)
/  To enable it, also _FS_TINY need to be 1. *//*---------------------------------------------------------------------------/
/ Locale and Namespace Configurations
/---------------------------------------------------------------------------*/
//这个改成1，再把中文支持的文件给删了
#define _CODE_PAGE  1
/* This option specifies the OEM code page to be used on the target system.
/  Incorrect setting of the code page can cause a file open failure.
/
/   1   - ASCII (No extended character. Non-LFN cfg. only)
/   437 - U.S.
/   720 - Arabic
/   737 - Greek
/   771 - KBL
/   775 - Baltic
/   850 - Latin 1
/   852 - Latin 2
/   855 - Cyrillic
/   857 - Turkish
/   860 - Portuguese
/   861 - Icelandic
/   862 - Hebrew
/   863 - Canadian French
/   864 - Arabic
/   865 - Nordic
/   866 - Russian
/   869 - Greek 2
/   932 - Japanese (DBCS)
/   936 - Simplified Chinese (DBCS)
/   949 - Korean (DBCS)
/   950 - Traditional Chinese (DBCS)
*///这里必须改成零不然编译不过
#define _USE_LFN    0
//#define   _MAX_LFN    255
/* The _USE_LFN switches the support of long file name (LFN).
/
/   0: Disable support of LFN. _MAX_LFN has no effect.
/   1: Enable LFN with static working buffer on the BSS. Always NOT thread-safe.
/   2: Enable LFN with dynamic working buffer on the STACK.
/   3: Enable LFN with dynamic working buffer on the HEAP.
/
/  To enable the LFN, Unicode handling functions (option/unicode.c) must be added
/  to the project. The working buffer occupies (_MAX_LFN + 1) * 2 bytes and
/  additional 608 bytes at exFAT enabled. _MAX_LFN can be in range from 12 to 255.
/  It should be set 255 to support full featured LFN operations.
/  When use stack for the working buffer, take care on stack overflow. When use heap
/  memory for the working buffer, memory management functions, ff_memalloc() and
/  ff_memfree(), must be added to the project. */#define    _LFN_UNICODE    0
/* This option switches character encoding on the API. (0:ANSI/OEM or 1:Unicode)
/  To use Unicode string for the path name, enable LFN and set _LFN_UNICODE = 1.
/  This option also affects behavior of string I/O functions. */#define _STRF_ENCODE    0
/* When _LFN_UNICODE == 1, this option selects the character encoding on the file to
/  be read/written via string I/O functions, f_gets(), f_putc(), f_puts and f_printf().
/
/  0: ANSI/OEM
/  1: UTF-16LE
/  2: UTF-16BE
/  3: UTF-8
/
/  This option has no effect when _LFN_UNICODE == 0. */#define _FS_RPATH  0
/* This option configures support of relative path.
/
/   0: Disable relative path and remove related functions.
/   1: Enable relative path. f_chdir() and f_chdrive() are available.
/   2: f_getcwd() function is available in addition to 1.
*//*---------------------------------------------------------------------------/
/ Drive/Volume Configurations
/---------------------------------------------------------------------------*/#define _VOLUMES  3   //支持3个磁盘
/* Number of volumes (logical drives) to be used. */#define _STR_VOLUME_ID  0
#define _VOLUME_STRS    "RAM","NAND","CF","SD1","SD2","USB1","USB2","USB3"
/* _STR_VOLUME_ID switches string support of volume ID.
/  When _STR_VOLUME_ID is set to 1, also pre-defined strings can be used as drive
/  number in the path name. _VOLUME_STRS defines the drive ID strings for each
/  logical drives. Number of items must be equal to _VOLUMES. Valid characters for
/  the drive ID strings are: A-Z and 0-9. */#define _MULTI_PARTITION    0
/* This option switches support of multi-partition on a physical drive.
/  By default (0), each logical drive number is bound to the same physical drive
/  number and only an FAT volume found on the physical drive will be mounted.
/  When multi-partition is enabled (1), each logical drive number can be bound to
/  arbitrary physical drive and partition listed in the VolToPart[]. Also f_fdisk()
/  funciton will be available. */#define    _MIN_SS     512
#define _MAX_SS     512
/* These options configure the range of sector size to be supported. (512, 1024,
/  2048 or 4096) Always set both 512 for most systems, all type of memory cards and
/  harddisk. But a larger value may be required for on-board flash memory and some
/  type of optical media. When _MAX_SS is larger than _MIN_SS, FatFs is configured
/  to variable sector size and GET_SECTOR_SIZE command must be implemented to the
/  disk_ioctl() function. */#define _USE_TRIM   0
/* This option switches support of ATA-TRIM. (0:Disable or 1:Enable)
/  To enable Trim function, also CTRL_TRIM command should be implemented to the
/  disk_ioctl() function. */#define _FS_NOFSINFO    0
/* If you need to know correct free space on the FAT32 volume, set bit 0 of this
/  option, and f_getfree() function at first time after volume mount will force
/  a full FAT scan. Bit 1 controls the use of last allocated cluster number.
/
/  bit0=0: Use free cluster count in the FSINFO if available.
/  bit0=1: Do not trust free cluster count in the FSINFO.
/  bit1=0: Use last allocated cluster number in the FSINFO if available.
/  bit1=1: Do not trust last allocated cluster number in the FSINFO.
*//*---------------------------------------------------------------------------/
/ System Configurations
/---------------------------------------------------------------------------*/#define   _FS_TINY    0
/* This option switches tiny buffer configuration. (0:Normal or 1:Tiny)
/  At the tiny configuration, size of the file object (FIL) is reduced _MAX_SS bytes.
/  Instead of private sector buffer eliminated from the file object, common sector
/  buffer in the file system object (FATFS) is used for the file data transfer. *///把这个也关了
#define _FS_EXFAT   0
/* This option switches support of exFAT file system in addition to the traditional
/  FAT file system. (0:Disable or 1:Enable) To enable exFAT, also LFN must be enabled.
/  Note that enabling exFAT discards C89 compatibility. */#define _FS_NORTC 0
#define _NORTC_MON  3
#define _NORTC_MDAY 1
#define _NORTC_YEAR 2016
/* The option _FS_NORTC switches timestamp functiton. If the system does not have
/  any RTC function or valid timestamp is not needed, set _FS_NORTC = 1 to disable
/  the timestamp function. All objects modified by FatFs will have a fixed timestamp
/  defined by _NORTC_MON, _NORTC_MDAY and _NORTC_YEAR in local time.
/  To enable timestamp function (_FS_NORTC = 0), get_fattime() function need to be
/  added to the project to get current time form real-time clock. _NORTC_MON,
/  _NORTC_MDAY and _NORTC_YEAR have no effect.
/  These options have no effect at read-only configuration (_FS_READONLY = 1). */#define   _FS_LOCK    0
/* The option _FS_LOCK switches file lock function to control duplicated file open
/  and illegal operation to open objects. This option must be 0 when _FS_READONLY
/  is 1.
/
/  0:  Disable file lock function. To avoid volume corruption, application program
/      should avoid illegal open, remove and rename to the open objects.
/  >0: Enable file lock function. The value defines how many files/sub-directories
/      can be opened simultaneously under file lock control. Note that the file
/      lock control is independent of re-entrancy. */#define _FS_REENTRANT  0
#define _FS_TIMEOUT     1000
#define _SYNC_t         HANDLE
/* The option _FS_REENTRANT switches the re-entrancy (thread safe) of the FatFs
/  module itself. Note that regardless of this option, file access to different
/  volume is always re-entrant and volume control functions, f_mount(), f_mkfs()
/  and f_fdisk() function, are always not re-entrant. Only file/directory access
/  to the same volume is under control of this function.
/
/   0: Disable re-entrancy. _FS_TIMEOUT and _SYNC_t have no effect.
/   1: Enable re-entrancy. Also user provided synchronization handlers,
/      ff_req_grant(), ff_rel_grant(), ff_del_syncobj() and ff_cre_syncobj()
/      function, must be added to the project. Samples are available in
/      option/syscall.c.
/
/  The _FS_TIMEOUT defines timeout period in unit of time tick.
/  The _SYNC_t defines O/S dependent sync object type. e.g. HANDLE, ID, OS_EVENT*,
/  SemaphoreHandle_t and etc.. A header file for O/S definitions needs to be
/  included somewhere in the scope of ff.c. *//*--- End of configuration options ---*/

大概就是这些修改。最后编译一下。

大概25K作为bootload还是非常小巧的吗。

还有就是一些基础的配置。

还有一个非常关键的地方就是
在APP程序中要设置偏移量。
SCB->VTOR = FLASH_BASE | 0x10000;//设置偏移量。

这就差不多了，这个BOOTLOAD程序使用方法为：事先烧入bootload程序然后将APP工程镜像命名为1.bin（怎么搞到镜像去看原子的文档）添加到SD卡UPDATE文件夹下，开机后自动更新，更新完成自动启动APP。在下一次启动前删除1.bin即可。

源码我就放在底下了：

STM32F429bootload V1.0