art1前言

在進行Flash操作時，一般我們需要設計一套Flash抽象層，至少要包括flash的init，read、write、erase這些操作。但每更換一個單片機或者flash器件就要額外去編寫flash驅動去適配init，read、write、erase。盡管有會者不難的屬性加持，但適配所有的單片機或者flash器件，工作量也可想而知。

本文為大家提供一個適配幾乎任意單片機型號的flash驅動，之所以說是幾乎，是因為我們這次要借東風，而這個東風就是Keil的FLM文件。

項目開源地址：https://gitee.com/Aladdin-Wang/flash_blob

Part2一、FLM文件是什么？

熟悉Keil的朋友們都知道，當我們要下載編譯好的鏡像到Flash時，首先要做的一步就是選擇合適的Flash下載算法，而這個算法本身就是一個FLM文件：

所謂Flash下載算法，是負責擦除，下載應用數據到flash的一個軟件。而Keil往往會集成不少FLM文件以支持大多數的flash型號。當然，這些算法也是根據不同型號的flash所編寫的。只不過，前人們已經為我們種好了大樹，我們可以直接在樹下乘涼了。

嵌入式物聯網需要學的東西真的非常多，千萬不要學錯了路線和內容，導致工資要不上去！

無償分享大家一個資料包，差不多150多G。里面學習內容、面經、項目都比較新也比較全！某魚上買估計至少要好幾十。

點擊這里找小助理0元領?。杭游⑿蓬I取資料

Part3二、FLM文件結構

Keil規定了FLM文件的構成，它是一成不變的，我們才可以放心的對文件本身進行解析，并為自己所用。

生成FLM文件的程序中，有兩個非常重要的文件，分別是

• FlashPrg.c中包含編程算法。
• FlashDev.c中包含設備參數。

11.FlashPrg.c

FlashPrg.c文件包含強制性flash編程函數Init、UnInit、EraseSector和ProgramPage。可選地，根據設備特性，可以實現函數EraseChip、BlankCheck和Verify 。

Function NameIndicationDescriptionBlankCheckoptionalCheck and compare patterns.EraseChipoptionalDelete entire Flash memory content.EraseSectormandatoryDelete Flash memory content of a specific sector.InitmandatoryInitialize and prepare device for Flash programming.ProgramPagemandatoryWrite the application into the Flash memory.UnInitmandatoryDe-initialize the microcontroller after one of the Flash programming steps.VerifyoptionalCompare Flash memory content with the program code.

其中有4個是必須要有的，我們來逐一說明：

1. Init 函數Init為 Flash 編程初始化微控制器。每當嘗試將程序下載到 Flash 時都會調用它。

int Init (unsigned long adr, unsigned long clk, unsigned long fnc);

參數adr指定設備的基址。

參數clk指定用于編程設備的時鐘頻率。

參數fnc是一個數字：

1 代表擦除。2代表程序。3代表驗證。

Code Example：

int Init (unsigned long adr, unsigned long clk, unsigned long fnc) {
 
  // Zero Wait State
  FLASH->ACR=0x00000000;
 
  // Unlock Flash
  FLASH->KEYR=FLASH_KEY1;
  FLASH->KEYR=FLASH_KEY2;
 
  // Test if IWDG is running (IWDG in HW mode)
  if ((FLASH->OBR & 0x04)==0x00) {
    // Set IWDG time out to ~32.768 second
    IWDG->KR=0x5555; // Enable write access to IWDG_PR and IWDG_RLR
    IWDG->PR=0x06;   // Set prescaler to 256
    IWDG->RLR=4095;   // Set reload value to 4095
  }
 
  return (0);
}

2. ProgramPage 函數ProgramPage用于將代碼寫入閃存。它被調用以將程序下載到 Flash。由于flash通常以塊或頁的形式組織，因此函數ProgramPage的參數不得跨越這些閃存頁的對齊邊界。頁面大小在結構 FlashDevice 中指定，值為Program Page Size。

int ProgramPage ( unsigned  long adr, unsigned  long sz, unsigned  char *buf);

參數adr指定要編程的頁面的起始地址。它由主機編程系統與flash頁面的起始地址對齊。

參數sz指定數據緩沖區中的數據大小。主機編程系統確保不跨越頁面邊界。

參數buf指向包含要編程的數據的數據緩沖區。

Code Example：

int ProgramPage (unsigned long adr, unsigned long sz, unsigned char *buf) {
 
  sz=(sz + 1) & ~1;                           // Adjust size for Half Words
 
  while (sz) {
 
    FLASH->CR |=FLASH_PG;                     // Programming Enabled
 
    M16(adr)=*((unsigned short *)buf);        // Program Half Word
    while (FLASH->SR & FLASH_BSY);
 
    FLASH->CR &=~FLASH_PG;                     // Programming Disabled
 
    // Check for Errors
    if (FLASH->SR & (FLASH_PGERR | FLASH_WRPRTERR)) {
      FLASH->SR |=FLASH_PGERR | FLASH_WRPRTERR;
      return (1);                               // Failed
    }
 
    // Go to next Half Word
    adr +=2;
    buf +=2;
    sz  -=2;
  }
 
  return (0);                                   // Done
}

3. EraseSector 函數EraseSector刪除從參數adr指定的地址開始的扇區內容。

int EraseSector (unsigned long adr);

參數adr扇區地址

Code Example：

int EraseSector (unsigned long adr) {
 
  FLASH->CR |=FLASH_PER;                      // Page Erase Enabled
  FLASH->AR=adr;                            // Page Address
  FLASH->CR |=FLASH_STRT;                     // Start Erase
 
  while (FLASH->SR & FLASH_BSY) {
    IWDG->KR=0xAAAA;                          // Reload IWDG
  }
 
  FLASH->CR &=~FLASH_PER;                      // Page Erase Disabled
 
  return (0);                                   // Done
}

4. UnInit 函數UnInit取消初始化微控制器，并在擦除、編程或驗證步驟結束時調用。

int UnInit (unsigned long fnc);

Code Example

int UnInit (unsigned long fnc) {
 
  // Lock Flash
  FLASH->CR |=FLASH_LOCK;
 
  return (0);
}

22.FlashPrg.c

文件FlashDev.c包含以下參數定義：

1. Flash編程功能。
2. FlashDevice結構：

struct FlashDevice const FlashDevice={
   FLASH_DRV_VERS,              // 驅動版本，請勿修改！
   "New Device 256kB Flash" ,    // 設備名稱
   ONCHIP,                      // 設備類型
   0x00000000,                  // 設備起始地址
   0x00040000,                  // 以字節為單位的設備大小 (256kB)
   1024,                        // 編程頁面大小
   0,                           // 保留，必須為0
   0xFF,                        // 已擦除內存的初始內容
   100,                         // 程序頁面超時 100 毫秒
   3000,                        // 擦除扇區超時 3000 毫秒
 
// 指定扇區的大小和地址
   0x002000, 0x000000,          // 扇區大小 8kB（8 個扇區）
   0x010000, 0x010000,          // 扇區大小 64kB（2 個扇區）
   0x002000, 0x030000,          // 扇區大小 8kB（8 個扇區）
   SECTOR_END
};

Device Name通常顯示在工具中，用于識別 Flash 算法。確保此名稱反映設備名稱。編程頁面大小指定使用函數ProgramPage進行編程 的塊大小。對于塊大小較小的設備，最好指定物理塊大小的倍數，因為這可以減少與目標的通信開銷?？焖倬幊痰淖罴褖K大小為 1024 字節，但系統本身并不限制此大小值。

Part4三、解析FLM文件

31.解析flm文件

下面讓我們解析一下現有的FLM文件，以STM32F4xx_1024.FLM為例：將ARM:CMSIS Pack文件夾（通常在D:\Users\Administrator\AppData\Local\Arm\Packs\Keil\STM32F4xx_DFP.15.0\CMSIS\Flash）中的內容復制到一個新文件夾中。

打開命令行工具，輸入arm-none-eabi-readelf -a STM32F4xx_1024.FLM：

$ arm-none-eabi-readelf -a STM32F4xx_1024.FLM
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x0
  Start of program headers:          12172 (bytes into file)
  Start of section headers:          12236 (bytes into file)
  Flags:                             0x5000000, Version5 EABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         2
  Size of section headers:           40 (bytes)
  Number of section headers:         16
  Section header string table index: 15

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] PrgCode           PROGBITS        00000000 000034 000144 00  AX  0   0  4
  [ 2] PrgData           PROGBITS        00000144 000178 000004 00  WA  0   0  4
  [ 3] DevDscr           PROGBITS        00000148 00017c 0010a0 00   A  0   0  4
  [ 4] .debug_abbrev     PROGBITS        00000000 00121c 0005a4 00      0   0  1
  [ 5] .debug_frame      PROGBITS        00000000 0017c0 000104 00      0   0  1
  [ 6] .debug_info       PROGBITS        00000000 0018c4 00064c 00      0   0  1
  [ 7] .debug_line       PROGBITS        00000000 001f10 000218 00      0   0  1
  [ 8] .debug_loc        PROGBITS        00000000 002128 0001b8 00      0   0  1
  [ 9] .debug_macinfo    PROGBITS        00000000 0022e0 000614 00      0   0  1
  [10] .debug_pubnames   PROGBITS        00000000 0028f4 000096 00      0   0  1
  [11] .symtab           SYMTAB          00000000 00298c 000110 10     12   9  4
  [12] .strtab           STRTAB          00000000 002a9c 000100 00      0   0  1
  [13] .note             NOTE            00000000 002b9c 00001c 00      0   0  4
  [14] .comment          PROGBITS        00000000 002bb8 000334 00      0   0  1
  [15] .shstrtab         STRTAB          00000000 002eec 0000a0 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
  L (link order), O (extra OS processing required), G (group), T (TLS),
  C (compressed), x (unknown), o (OS specific), E (exclude),
  y (purecode), p (processor specific)

There are no section groups in this file.

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x000034 0x00000000 0x00000000 0x00148 0x00148 RWE 0x4
  LOAD           0x00017c 0x00000148 0x00000148 0x010a0 0x010a0 R   0x4

 Section to Segment mapping:
  Segment Sections...
   00     PrgCode PrgData
   01     DevDscr

There is no dynamic section in this file.

There are no relocations in this file.

There are no unwind sections in this file.

Symbol table '.symtab' contains 17 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 NOTYPE  LOCAL  DEFAULT    1 $t
     2: 00000122     0 NOTYPE  LOCAL  DEFAULT    1 $d
     3: 00000144     0 NOTYPE  LOCAL  DEFAULT    2 $d.realdata
     4: 00000148     0 NOTYPE  LOCAL  DEFAULT    3 $d.realdata
     5: 00000000     0 FILE    LOCAL  DEFAULT  ABS FlashPrg.c
     6: 00000000     0 SECTION LOCAL  DEFAULT    1 .text
     7: 00000000     0 FILE    LOCAL  DEFAULT  ABS FlashDev.c
     8: 00000148  4256 SECTION LOCAL  DEFAULT    3 .constdata
     9: 00000000     0 NOTYPE  GLOBAL HIDDEN   ABS BuildAttributes$$THM_ISAv
    10: 00000001    28 FUNC    GLOBAL HIDDEN     1 GetSecNum
    11: 0000001d    46 FUNC    GLOBAL HIDDEN     1 Init
    12: 0000004b    14 FUNC    GLOBAL HIDDEN     1 UnInit
    13: 00000059    44 FUNC    GLOBAL HIDDEN     1 EraseChip
    14: 00000085    76 FUNC    GLOBAL HIDDEN     1 EraseSector
    15: 000000d1    82 FUNC    GLOBAL HIDDEN     1 ProgramPage
    16: 00000148  4256 OBJECT  GLOBAL HIDDEN     3 FlashDevice

No version information found in this file.

Displaying notes found at file offset 0x00002b9c with length 0x0000001c:
  Owner                 Data size       Description
  ARM                  0x0000000c       Unknown note type: (0x40000000)

通過Symbol table信息我們可以找到Init、UnInit、EraseSector和ProgramPage函數所在的位置。

我們還需要根據Section Headers所描述的位置提取出Prgcode(代碼)，PrgData(數據)，DevDscr(設備描述)的信息。

在命令行中輸入arm-none-eabi-objdum -s -d STM32F4xx_1024.FLM：-s參數可以將所有段的內容一十六進制方式打印出來，-d參數可以將所有包含指令的段反匯編。

$ arm-none-eabi-objdump -s -d STM32F4xx_1024.FLM

STM32F4xx_1024.FLM:     file format elf32-littlearm

Contents of section PrgCode:
 0000 0003000e 202802d3 4009001d 70471028  .... (..@...pG.(
 0010 02d30009 c01c7047 80087047 42484149  ......pG..pGBHAI
 0020 41604249 41600021 0160c168 f0221143  A`BIA`.!.`.h.".C
 0030 c1604069 800606d4 3e483d49 01600621  .`@i....>H=I.`.!
 0040 41603d49 81600020 70473748 01694205  A`=I.`. pG7H.iB.
 0050 11430161 00207047 10b53348 01690424  .C.a. pG..3H.i.$
 0060 21430161 0169a203 11430161 3349314a  !C.a.i...C.a3I1J
 0070 00e01160 c368db03 fbd40169 a1430161  ...`.h.....i.C.a
 0080 002010bd 30b5fff7 bbff2749 ca68f023  . ..0.....'I.h.#
 0090 1a43ca60 02240c61 0a690007 400e0243  .C.`.$.a.i..@..C
 00a0 0a610869 e2031043 08612448 214a00e0  .a.i...C.a$H!J..
 00b0 1060cd68 ed03fbd4 0869a043 0861c868  .`.h.....i.C.a.h
 00c0 0006000f 03d0c868 1843c860 012030bd  .......h.C.`. 0.
 00d0 70b5154d c91c8908 eb688900 f0263343  p..M.....h...&3C
 00e0 eb600023 2b61164b 17e02c69 1c432c61  .`.#+a.K..,i.C,a
 00f0 14680460 ec68e403 fcd42c69 64086400  .h.`.h....,id.d.
 0100 2c61ec68 2406240f 04d0e868 3043e860  ,a.h$.$....h0C.`
 0110 012070bd 001d121d 091f0029 e5d10020  . p........)...
 0120 70bd0000 23016745 003c0240 ab89efcd  p...#.gE.<.@....
 0130 55550000 00300040 ff0f0000 aaaa0000  UU...0.@........
 0140 01020000                             ....
Contents of section PrgData:
 0144 00000000                             ....
Contents of section DevDscr:
 0148 01015354 4d333246 34787820 466c6173  ..STM32F4xx Flas
 0158 68000000 00000000 00000000 00000000  h...............
 0168 00000000 00000000 00000000 00000000  ................
 0178 00000000 00000000 00000000 00000000  ................
 0188 00000000 00000000 00000000 00000000  ................
 0198 00000000 00000000 00000000 00000000  ................
 01a8 00000000 00000000 00000000 00000000  ................
 01b8 00000000 00000000 00000000 00000000  ................
 01c8 00000100 00000008 00001000 00040000  ................
 01d8 00000000 ff000000 64000000 70170000  ........d...p...
 01e8 00400000 00000000 00000100 00000100  .@..............
 01f8 00000200 00000200 ffffffff ffffffff  ................

我們所需要的正是以上信息，接下來的任務只需要寫一個上位機，將以上文件提取出來即可，這個工具我已經寫好，如圖：

選擇STM32F4xx_1024.FLM，生成STM32F4xx_1024.FLM.c文件，然后直接添加到我們的工程中即可，生成的代碼如下：

#include "flash_blob.h" 

#define OPS_OFFSET ((uint32_t)&flash_code)

#define DEV_OFFSET ((uint32_t)&flash_dev)

#define RAM_OFFSET ((uint32_t)&rw_data)

static const uint32_t flash_code[]={
    0X0E000300,0XD3022820,0X1D000940,0X28104770,0X0900D302,0X47701CC0,0X47700880,0X49414842,
    0X49426041,0X21036041,0X68C16001,0X431122F0,0X694060C1,0XD4060680,0X493D483E,0X21066001,
    0X493D6041,0X20006081,0X48374770,0X05426901,0X61014311,0X47702000,0X4833B510,0X24046901,
    0X61014321,0X03A26901,0X61014311,0X4A314933,0X6011E000,0X03DB68C3,0X6901D4FB,0X610143A1,
    0XBD102000,0XF7FFB530,0X4927FFBB,0X23F068CA,0X60CA431A,0X610C2402,0X0700690A,0X43020E40,
    0X6908610A,0X431003E2,0X48246108,0XE0004A21,0X68CD6010,0XD4FB03ED,0X43A06908,0X68C86108,
    0X0F000600,0X68C8D003,0X60C84318,0XBD302001,0X4D15B570,0X08891CC9,0X008968EB,0X433326F0,
    0X230060EB,0X4B16612B,0X692CE017,0X612C431C,0X60046814,0X03E468EC,0X692CD4FC,0X00640864,
    0X68EC612C,0X0F240624,0X68E8D004,0X60E84330,0XBD702001,0X1D121D00,0X29001F09,0X2000D1E5,
    0X0000BD70,0X45670123,0X40023C00,0XCDEF89AB,0X00005555,0X40003000,0X00000FFF,0X0000AAAA,
    0X00000201,0X00000000,
};

static const uint32_t flash_dev[]={
    0X54530101,0X4632334D,0X20787834,0X73616C46,0X00000068,0X00000000,0X00000000,0X00000000,
    0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,
    0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,
    0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,0X00000000,
    0X00010000,0X08000000,0X00100000,0X00000400,0X00000000,0X000000FF,0X00000064,0X00001770,
    0X00004000,0X00000000,0X00010000,0X00010000,0X00020000,0X00020000,0XFFFFFFFF,0XFFFFFFFF,
};

static uint32_t rw_data[]={
    0X00000000,
};

static flash_blob_device_t  flash_device={
    (void*)(OPS_OFFSET + 0X001D),  // Init
    (void*)(OPS_OFFSET + 0X004B),  // UnInit
    (void*)(OPS_OFFSET + 0X0059),  // EraseChip
    (void*)(OPS_OFFSET + 0X0085),  // EraseSector
    (void*)(OPS_OFFSET + 0X00D1),  // ProgramPage
    (void*)(DEV_OFFSET),
    (void*)(RAM_OFFSET),
};
static int flash_blob_device_register(void) 
{                                            
    flash_dev_register(&flash_device);       
    return 0 ;                                
}                                               
INIT_BOARD_EXPORT(flash_blob_device_register);

Part5四、設計flash驅動抽象層

接下來，為了方便后續使用，需要設計一個flash驅動抽象層，代碼如下：flash_blob.h

#ifndef FLASH_BLOB_H
#define FLASH_BLOB_H
#include "rtthread.h"
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>

#define VERS       1           // Interface Version 1.01

#define UNKNOWN    0           // Unknown
#define ONCHIP     1           // On-chip Flash Memory
#define EXT8BIT    2           // External Flash Device on 8-bit  Bus
#define EXT16BIT   3           // External Flash Device on 16-bit Bus
#define EXT32BIT   4           // External Flash Device on 32-bit Bus
#define EXTSPI     5           // External Flash Device on SPI

#define SECTOR_NUM 16         // Max Number of Sector Items

struct FlashSectors  {
  unsigned long   szSector;    // Sector Size in Bytes
  unsigned long AddrSector;    // Address of Sector
};

typedef struct FlashDevice  {
   unsigned short     Vers;    // Version Number and Architecture
   char       DevName[128];    // Device Name and Description
   unsigned short  DevType;    // Device Type: ONCHIP, EXT8BIT, EXT16BIT, ...
   unsigned long    DevAdr;    // Default Device Start Address
   unsigned long     szDev;    // Total Size of Device
   unsigned long    szPage;    // Programming Page Size
   unsigned long       Res;    // Reserved for future Extension
   unsigned char  valEmpty;    // Content of Erased Memory

   unsigned long    toProg;    // Time Out of Program Page Function
   unsigned long   toErase;    // Time Out of Erase Sector Function

   struct FlashSectors sectors[SECTOR_NUM];
}flash_dev_t;

typedef struct {
 int (*Init)(uint32_t adr, uint32_t clk, uint32_t fnc);
 int (*UnInit)(uint32_t fnc);
 int (*EraseChip)(void);
 int (*EraseSector)(uint32_t adr);
 int (*ProgramPage)(uint32_t adr, uint32_t sz, uint8_t* buf);  
}flash_ops_t;

typedef struct
{
    flash_ops_t tFlashops;
    flash_dev_t *ptFlashDev;
    int *pPrgData;
    rt_slist_t slist;      
}flash_blob_t;

extern void flash_dev_register(flash_blob_t *ptFlashDevice);
extern bool target_flash_init(uint32_t flash_start, int32_t size);
extern bool target_flash_uninit(uint32_t flash_start);
extern int32_t target_flash_write(uint32_t addr, const uint8_t *buf, int32_t size);
extern int32_t target_flash_erase(uint32_t addr, int32_t size);
extern int32_t target_flash_read(uint32_t addr, const uint8_t *buf, int32_t size);
#endif

flash_blob.c

#include "flash_blob.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"

static bool s_bIsInit=false;
static rt_slist_t _slist_head=RT_SLIST_OBJECT_INIT(_slist_head);
register int *pPrgDataBase __asm("r9");

void flash_dev_register(flash_blob_t *ptFlashDevice)
{
    rt_slist_init(&(ptFlashDevice->slist));
    rt_slist_append(&_slist_head, &(ptFlashDevice->slist));
}

static flash_blob_t * flash_dev_find(uint32_t flash_start)
{
    rt_slist_t *node;
    rt_slist_for_each(node, &_slist_head) {
        flash_blob_t *ptFlashDevice=rt_slist_entry(node, flash_blob_t, slist);

        if(flash_start >=ptFlashDevice->ptFlashDev->DevAdr &&
           flash_start < ptFlashDevice->ptFlashDev->DevAdr + ptFlashDevice->ptFlashDev->szDev) {
            return ptFlashDevice;
        }
    }
    return NULL;
}

bool target_flash_init(uint32_t flash_start, int32_t size)
{
    if (flash_start % 4 !=0) {
        LOG_E("flash addr must be 4-byte alignment");
        return NULL;
    }

    flash_blob_t *ptFlashDevice=flash_dev_find(flash_start);

    if(ptFlashDevice !=NULL) {
        pPrgDataBase=ptFlashDevice->pPrgData;
        ptFlashDevice->tFlashops.Init(flash_start, 0, 0);
        return true;
    }

    return false;
}

bool target_flash_uninit(uint32_t flash_start)
{
    flash_blob_t *ptFlashDevice=flash_dev_find(flash_start);

    if(ptFlashDevice !=NULL) {
        pPrgDataBase=ptFlashDevice->pPrgData;
        ptFlashDevice->tFlashops.UnInit(flash_start);
        return true;
    }

    return true;
}

int target_flash_write(uint32_t addr, const uint8_t *buf, int32_t size)
{
    flash_blob_t *ptFlashDevice=flash_dev_find(addr);

    if(ptFlashDevice !=NULL) {
        pPrgDataBase=ptFlashDevice->pPrgData;

        while(size > 0) {
            uint32_t write_size=size > ptFlashDevice->ptFlashDev->szPage ? ptFlashDevice->ptFlashDev->szPage : size;

            if( 0 !=ptFlashDevice->tFlashops.ProgramPage(addr, write_size, (uint8_t *)buf)) {
                LOG_E("Programming Failed");
                return -1;
            }

            addr +=write_size;
            buf  +=write_size;
            size -=write_size;
        }

        return size;
    }

    return -1;
}

int32_t target_flash_read(uint32_t addr, const uint8_t *buf, int32_t size)
{
    flash_blob_t *ptFlashDevice;
    pPrgDataBase=ptFlashDevice->pPrgData;
    return size;
}

int32_t target_flash_erase(uint32_t addr, int32_t size)
{
    int32_t wSector, wRemainLen;
    flash_blob_t *ptFlashDevice=flash_dev_find(addr);

    if(ptFlashDevice !=NULL) {
        if (size > ptFlashDevice->ptFlashDev->szDev) {
            LOG_E("erase outrange flash size! addr is (0x%p)\n", (void *)(addr + size));
            return -1;
        }

        pPrgDataBase=ptFlashDevice->pPrgData;
        wRemainLen=size;
        while(wRemainLen > 0) {
            if(0 !=ptFlashDevice->tFlashops.EraseSector(addr)) {
                LOG_E("erase Failed! addr is (0x%p)\n", (void *)addr);
                return -1;
            }

            for(wSector=0; wSector < SECTOR_NUM; wSector++) {
                if(ptFlashDevice->ptFlashDev->sectors[wSector + 1].szSector==0XFFFFFFFF )
                    break;

                if(((addr - ptFlashDevice->ptFlashDev->DevAdr) < ptFlashDevice->ptFlashDev->sectors[wSector + 1].AddrSector) &&
                   ((addr - ptFlashDevice->ptFlashDev->DevAdr) >=ptFlashDevice->ptFlashDev->sectors[wSector].AddrSector) )
                    break;
            }

            addr +=ptFlashDevice->ptFlashDev->sectors[wSector].szSector;
            wRemainLen -=ptFlashDevice->ptFlashDev->sectors[wSector].szSector;
        }

        return size;
    }

    return -1;
}

int32_t target_flash_verify (uint32_t addr, uint8_t *buf, int32_t size)
{

    return size;
}

Part6五、快速使用

本項目借用了rtthread的自動初始化機制和鏈表，所以最快的使用方式是直接作為rtthread的軟件包使用，使用方法如下：

1. 在rtthread軟件包中找到flash_blob，然后添加進工程。
2. 通過tools文件下的工具，生成對應的xxx.FLM.c文件，將xxx.FLM.c添加進工程，如果有多個flash器件，可以連續添加。
3. 注意：多個設備的話每個flash的FlashDevice 的設備起始地址不可重疊，flash接口根據地址，自動選擇相應的驅動。
4. 由于flash驅動需要占用“r9”寄存器，所以需要在編譯選項中添加-ffixed-r9

以上步驟完成后，就可以快速使用了，例如將YMODEM接收到的數據，寫到flash中，代碼如下：

uint8_t *ymodem_call_back_receive(uint8_t *pchBuffer, uint16_t hwSize)
{
    static char *s_pchFileName=NULL, *s_pchFileSize=NULL;
    static uint32_t s_wFileSize=0, s_wRemainLen=0, s_wOffSet=0;

    static enum  {
        START=0,
        RECEIVE,
        END,
    } s_tState={START};

    switch(s_tState) {
        case START:
            s_wOffSet=0;
            s_pchFileName=(char *)&pchBuffer[0];
            s_pchFileSize=(char *)&pchBuffer[strlen(s_pchFileName) + 1];
            s_wFileSize=atol(s_pchFileSize);

            LOG_D("Ymodem file_name:%s", s_pchFileName);
            LOG_D("Ymodem file_size:%d", s_wFileSize);

            if(target_flash_init(APP_PART_ADDR, s_wFileSize)==false) {
                LOG_E("target flash uninit.");
                return NULL;
            }

            if(target_flash_erase(APP_PART_ADDR, s_wFileSize) < 0) {
                LOG_E("target flash erase error.");
                return NULL;
            }

            s_tState=RECEIVE;
            break;

        case RECEIVE:
            s_wRemainLen=s_wFileSize - s_wOffSet;

            if(hwSize > s_wRemainLen) {
                hwSize=s_wRemainLen;
                s_tState=END;
            }

            if(target_flash_write(APP_PART_ADDR + s_wOffSet, pchBuffer, hwSize) < 0) {
                LOG_E("target flash write data error.");
                return NULL;
            }

            s_wOffSet +=hwSize;

            break;

        case END:
            target_flash_uninit(APP_PART_ADDR);

            s_tState=START;
            break;
    }

    return s_chBuffer;
}

Part7五、彩蛋

本文介紹了如何利用Keil中FLM文件制作通用的flash驅動，但是總會遇到keil中沒有的外部flash芯片，下篇將介紹如何從零編寫生成FLM文件的工程，敬請期待...

轉載自：AIoT開源項目分享
文章來源于利用MDK的FLM文件制作通用flash驅動

原文鏈接：https://mp.weixin.qq.com/s/wi2PBfiAqqt6N_f-znAOEQ