本教程之記錄移植中關鍵過程，不講解原理。

1. 用cubemx生成工程

我這里用cubemx生成makefile工程。
幾個關鍵的點用圖片記錄下來

ETH1.png

接收描述符和發送描述符的地址特別注意，只能在D2域的RAM。

ETH2.png

開ETH中斷。

freertos1.png

lwip1.png

lwip2.png

lwip3.png

lwip4.png

MPU.png

2.makefile

在makefile文件中增加宏定義DATA_IN_D2_SRAM。

# C defines

C_DEFS = 

-DUSE_HAL_DRIVER

-DSTM32H743xx

-DDATA_IN_D2_SRAM

DATA_IN_D2_SRAM可以開啟D2域RAM的時鐘。在目錄CoreSrcsystem_stm32h7xx.c下有如幾行代碼。

#if defined(DATA_IN_D2_SRAM)

  /* in case of initialized data in D2 SRAM (AHB SRAM), enable the D2 SRAM clock (AHB SRAM clock) */#if defined(RCC_AHB2ENR_D2SRAM3EN)

  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);#elif defined(RCC_AHB2ENR_D2SRAM2EN)

  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN);#else

  RCC->AHB2ENR |= (RCC_AHB2ENR_AHBSRAM1EN | RCC_AHB2ENR_AHBSRAM2EN);#endif /* RCC_AHB2ENR_D2SRAM3EN */

用來開啟D2_RAM1、D2_RAM2和D2_RAM3的時鐘。這與很多網上教程中說的手動增加

__HAL_RCC_D2SRAM1_CLK_ENABLE();

__HAL_RCC_D2SRAM2_CLK_ENABLE();

__HAL_RCC_D2SRAM3_CLK_ENABLE();

是一樣的效果。

3. STM32H743IITx_FLASH.ld

3.1 首先在STM32H743IITx_FLASH.ld中增加如下代碼：

  /* ETH_CODE: add placement of DMA descriptors and RX buffers */

  .lwip_sec (NOLOAD) :

  {

    . = ABSOLUTE(0x30040000);

    *(.RxDecripSection)

    . = ABSOLUTE(0x30040100);

    *(.TxDecripSection)

    . = ABSOLUTE(0x30040200);

    *(.Rx_PoolSection)

  } >RAM_D2

為什么這里的地址間隔是0x100?

RAM_D2中開辟出來的兩個存儲空間RxDecripSection和TxDecripSection分別用來存儲ETH的描述符DMARxDscrTab和DMATxDscrTab。

//LWIPTargetethernetif.cETH_DMADescTypeDef DMARxDscrTab[ETH_RX_DESC_CNT] __attribute__((section('.RxDecripSection'))); /* Ethernet Rx DMA Descriptors */ETH_DMADescTypeDef DMATxDscrTab[ETH_TX_DESC_CNT] __attribute__((section('.TxDecripSection'))); /* Ethernet Tx DMA Descriptors */

ETH_RX_DESC_CNT= 4。

ETH_DMADescTypeDef 定義如下：

typedef struct{

  __IO uint32_t DESC0;

  __IO uint32_t DESC1;

  __IO uint32_t DESC2;

  __IO uint32_t DESC3;

  uint32_t BackupAddr0; /* used to store rx buffer 1 address */

  uint32_t BackupAddr1; /* used to store rx buffer 2 address */} ETH_DMADescTypeDef;

一個ETH_DMADescTypeDef 類型展6*4=24字節。DMARxDscrTab[ETH_RX_DESC_CNT]占用96個字節。0x100=256字節，完全能放下DMARxDscrTab[ETH_RX_DESC_CNT]。

DMARxDscrTab和DMATxDscrTab必須強制鏈接到.RxDecripSection和.TxDecripSection段上去，且RxDecripSection和TxDecripSection必須在D2域的RAM上。否則DMA報錯。

D2域有3塊RAM:

D2_SRAM1：0x3000 0000 ~ 0x3001 FFFF

D2_SRAM2：0x3002 0000 ~ 0x3003 FFFF

D2_SRAM3：0x3004 0000 ~ 0x3004 7FFF

3.2 DTCMRAM改RAM_D1

STM32H743IITx_FLASH.ld中有多處DTCMRAM需要改成RAM_D1。懶得一處一處的記錄，直接貼文件如下：

/*

******************************************************************************

**

**  File        : LinkerScript.ld

**

**  Author      : STM32CubeMX

**

**  Abstract    : Linker script for STM32H743IITx series

**                2048Kbytes FLASH and 1056Kbytes RAM

**

**                Set heap size, stack size and stack location according

**                to application requirements.

**

**                Set memory bank area and size if external memory is used.

**

**  Target      : STMicroelectronics STM32

**

**  Distribution: The file is distributed “as is,” without any warranty

**                of any kind.

**

*****************************************************************************

** @attention

**

**

© COPYRIGHT(c) 2019 STMicroelectronics

**

** Redistribution and use in source and binary forms, with or without modification,

** are permitted provided that the following conditions are met:

**   1. Redistributions of source code must retain the above copyright notice,

**      this list of conditions and the following disclaimer.

**   2. Redistributions in binary form must reproduce the above copyright notice,

**      this list of conditions and the following disclaimer in the documentation

**      and/or other materials provided with the distribution.

**   3. Neither the name of STMicroelectronics nor the names of its contributors

**      may be used to endorse or promote products derived from this software

**      without specific prior written permission.

**

** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS'

** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

** DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE

** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

**

*****************************************************************************

*//* Entry Point */ENTRY(Reset_Handler)/* Highest address of the user mode stack */_estack = ORIGIN(RAM_D1) + LENGTH(RAM_D1);    /* end of RAM *//* Generate a link error if heap and stack don't fit into RAM */_Min_Heap_Size = 0x200;      /* required amount of heap  */_Min_Stack_Size = 0x400; /* required amount of stack *//* Specify the memory areas */MEMORY{DTCMRAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 128KRAM_D1 (xrw)      : ORIGIN = 0x24000000, LENGTH = 512KRAM_D2 (xrw)      : ORIGIN = 0x30000000, LENGTH = 288KRAM_D3 (xrw)      : ORIGIN = 0x38000000, LENGTH = 64KITCMRAM (xrw)      : ORIGIN = 0x00000000, LENGTH = 64KFLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 2048K}/* Define output sections */SECTIONS{

  /* The startup code goes first into FLASH */

  .isr_vector :

  {

    . = ALIGN(4);

    KEEP(*(.isr_vector)) /* Startup code */

    . = ALIGN(4);

  } >FLASH

  /* The program code and other data goes into FLASH */

  .text :

  {

    . = ALIGN(4);

    *(.text)           /* .text sections (code) */

    *(.text*)          /* .text* sections (code) */

    *(.glue_7)         /* glue arm to thumb code */

    *(.glue_7t)        /* glue thumb to arm code */

    *(.eh_frame)

    KEEP (*(.init))

    KEEP (*(.fini))

    . = ALIGN(4);

    _etext = .;        /* define a global symbols at end of code */

  } >FLASH

  /* Constant data goes into FLASH */

  .rodata :

  {

    . = ALIGN(4);

    *(.rodata)         /* .rodata sections (constants, strings, etc.) */

    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */

    . = ALIGN(4);

  } >FLASH

  .ARM.extab   : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH

  .ARM : {

    __exidx_start = .;

    *(.ARM.exidx*)

    __exidx_end = .;

  } >FLASH

  .preinit_array     :

  {

    PROVIDE_HIDDEN (__preinit_array_start = .);

    KEEP (*(.preinit_array*))

    PROVIDE_HIDDEN (__preinit_array_end = .);

  } >FLASH

  .init_array :

  {

    PROVIDE_HIDDEN (__init_array_start = .);

    KEEP (*(SORT(.init_array.*)))

    KEEP (*(.init_array*))

    PROVIDE_HIDDEN (__init_array_end = .);

  } >FLASH

  .fini_array :

  {

    PROVIDE_HIDDEN (__fini_array_start = .);

    KEEP (*(SORT(.fini_array.*)))

    KEEP (*(.fini_array*))

    PROVIDE_HIDDEN (__fini_array_end = .);

  } >FLASH

  /* used by the startup to initialize data */

  _sidata = LOADADDR(.data);

  /* Initialized data sections goes into RAM, load LMA copy after code */

  .data : 

  {

    . = ALIGN(4);

    _sdata = .;        /* create a global symbol at data start */

    *(.data)           /* .data sections */

    *(.data*)          /* .data* sections */

    . = ALIGN(4);

    _edata = .;        /* define a global symbol at data end */

  } >RAM_D1 AT> FLASH

  /* Uninitialized data section */

  . = ALIGN(4);

  .bss :

  {

    /* This is used by the startup in order to initialize the .bss secion */

    _sbss = .;         /* define a global symbol at bss start */

    __bss_start__ = _sbss;

    *(.bss)

    *(.bss*)

    *(COMMON)

    . = ALIGN(4);

    _ebss = .;         /* define a global symbol at bss end */

    __bss_end__ = _ebss;

  } >RAM_D1

  /* User_heap_stack section, used to check that there is enough RAM left */

  ._user_heap_stack :

  {

    . = ALIGN(8);

    PROVIDE ( end = . );

    PROVIDE ( _end = . );

    . = . + _Min_Heap_Size;

    . = . + _Min_Stack_Size;

    . = ALIGN(8);

  } >RAM_D1

  /* ETH_CODE: add placement of DMA descriptors and RX buffers */

  .lwip_sec (NOLOAD) :

  {

    . = ABSOLUTE(0x30040000);

    *(.RxDecripSection)