MX6ULL使用UNIQUE ID配置网卡MAC地址

标签： imx6ull

前言:

貌似不管用什么ARM处理器都会遇到一个问题，那就是MAC地址唯一性，如果是使用随机的，每次reboot之后MAC地址都会变化，如果是在代码里面固定死了，如果局域网里面有两个设备的话，路由又会有问题。其实最大的问题就是量产的不方便。

以前用stm32的时候，可以使用stm32的唯一ID来配置给MAC地址使用，后来使用的zynq并没有，然后就使用的是板子上的flash的以为ID。最近在研究imx6ull，也是同样的问题，查了一下datasheet之后发现这款CPU也有唯一ID。下面是datasheet里面的介绍:

 

接下来就切入正题了：

本篇blog不做过程分析，因为之前zynq已经分析过一次了，我已经知道需要在什么地方做修改了。所以接下来只把需要做修改的地方给大家分享一下，有需要看分析过程的朋友可以参考我之前写的blog：ZYNQ通过读取SPI Flash的唯一ID来做MAC地址使用。

首先依照惯例还是先介绍一下平台,这里使用的开发板是韦东山老师的100ask_imx6ull开发板，是真的便宜。然后u-boot和kernel都是百问网提供的。

然后说一下需要修改什么，主要是修改u-boot和设备树，跟kernel关系不大。

接下来先修改u-boot:

根据datasheet 《i.MX 6ULL Applications Processor Reference Manual》 2404页的寄存器介绍，可以知道只需要把这两个寄存器里面的ID读出来就行了。

 

然后这里会有两个ID，因为一共是64位，所以肯定采购一批IC的话，高32位因为是不会变的，所以我们需要知道哪个寄存器里面存的是低32位。因为我手里只有一张开发板，所以我麻烦了一下交流群里面的朋友把它的ID截图给我看了一下。

第一张的群里朋友的截图，第二章是我这边读出来的，所以可以确定我们应该使用OCOTP_CFG1寄存器里面保存的ID。

打开u-boot源码里面 ./cmd/fdt.c 找到函数 void set_working_fdt_addr(ulong addr) 将函数内容替换成

1. void set_working_fdt_addr(ulong addr)

2. {

3. void *buf;

4. /* patch by hlb start */

5. #define B2L(x) (((x & 0xff000000) >> 24) | ((x & 0xff0000) >> 8) | ((x & 0xff00) << 8) | ((x & 0xff) << 24))

7. unsigned int off_dt_struct; /* offset to structure */

8. unsigned int off_dt_strings; /* offset to strings */

9. unsigned int off_mem_rsvmap; /* offset to memory reserve map */

11. unsigned int temp;

12. unsigned int len;

13. unsigned int name_off;

14. unsigned char* str;

15. unsigned char* node_name;

16. int root_node = 0;

17. int mac_cnt = 0;

18. unsigned int ID0 = *((volatile const unsigned int*)0x21BC410);

19. unsigned int ID1 = *((volatile const unsigned int*)0x21BC420);

20. printf("\nID0 = 0x%08x\n", ID0);

21. printf("ID1 = 0x%08x\n", ID1);

22. /* patch by hlb end */

23. buf = map_sysmem(addr, 0);

24. working_fdt = buf;

25. /* patch by hlb start*/

26. #if 0

27. printf("addr = 0x%08x\n", addr);

28. printf("buf = 0x%08x\n", buf);

29. #endif

31. off_dt_struct = B2L(working_fdt->off_dt_struct);

32. off_dt_strings = B2L(working_fdt->off_dt_strings);

33. off_mem_rsvmap = B2L(working_fdt->off_mem_rsvmap);

35. #if 0

36. printf("off_dt_struct = %d\n", off_dt_struct);

37. printf("off_dt_strings = %d\n", off_dt_strings);

38. printf("off_mem_rsvmap = %d\n", off_mem_rsvmap);

39. #endif

40. off_dt_struct += (unsigned int)working_fdt;

41. off_dt_strings += (unsigned int)working_fdt;

42. off_mem_rsvmap += (unsigned int)working_fdt;

44. do

45. {

46. temp = *((unsigned int*)off_dt_struct);

47. off_dt_struct += 4;

48. temp = B2L(temp);

49. switch (temp)

50. {

51. case 1:

52. if (root_node == 0) //处理根节点

53. {

54. root_node = 1;

55. off_dt_struct += 4; //根节点没有名字,跳过

56. }

57. else

58. {

59. /* node name */

60. node_name = (unsigned char*)off_dt_struct;

61. //printf("node name: %s\n", str);

63. int str_len;

64. str_len = strlen((const char*)node_name) + 1;

65. off_dt_struct += str_len;

66. if (str_len % 4)

67. {

68. off_dt_struct += 4 - (str_len % 4); //4字节对齐

69. }

70. }

71. break;

73. case 2:

74. break;

76. case 3:

77. /* value len */

78. temp = *((unsigned int*)off_dt_struct);

79. len = B2L(temp);

81. off_dt_struct += 4;

83. /* nameoff */

84. temp = *((unsigned int*)off_dt_struct);

85. name_off = B2L(temp);

86. str = (unsigned char*)(off_dt_strings + name_off);

88. off_dt_struct += 4;

90. if (strstr((char*)str, (const char*)"local-mac-address"))

91. {

92. unsigned char* pmac;

93. pmac = (unsigned char*)off_dt_struct;

95. #if 1

96. printf("Finding eth%d node name is: %s\n", mac_cnt, node_name);

97. printf("Old local-mac-address value len = %d\n", len);

98. for (int i = 0; i < 6; i++)

99. {

100. printf("0x%02x ", pmac[i]);

101. }

102. printf("\n");

103. #endif

104. pmac[0] = 0x00;

105. pmac[1] = 0x0a;

106. pmac[2] = 0x35 + mac_cnt++;

107. pmac[3] = (unsigned char)(ID1 >> 16);

108. pmac[4] = (unsigned char)(ID1 >> 8);

109. pmac[5] = (unsigned char)(ID1 >> 0);

111. #if 1

112. printf("Use ID1 value!\n");

113. printf("local-mac-address value len = %d\n", len);

114. for (int i = 0; i < 6; i++)

115. {

116. printf("0x%02x ", pmac[i]);

117. }

118. printf("\n\n");

119. #endif

120. }

123. off_dt_struct += len; //加上value长度偏移

124. if (len % 4)

125. {

126. off_dt_struct += 4 - (len % 4); //4字节对齐

127. }

128. break;

130. case 9:

131. off_dt_struct = 0;

132. break;

134. default:

135. break;

136. }

138. } while (off_dt_struct);

140. /* patch by hlb end */

141. setenv_hex("fdtaddr", addr);

142. }

该函数里面主要是实现了解析设备树，然后找到MAC地址的属性，将MAC地址的低三个字节替换成UID的低三个字节。保存编译一下，到这里u-boot基本上就算改完了，然后接下来还要修改设备树，因为我这版设备树里面是没有MAC地址属性的。然后设备树解析这里也不详细赘述了，有兴趣的同学自行查阅资料，或者是去买韦东山老师的设备树视频来看一下。（其实这不是软文）

打开kernel源码 ./arch/arm/boot/dts 里的 100ask_imx6ull-14x14.dts 文件，找到：fec1 和 fec2 节点，然后添加：

local-mac-address = [00 0a 35 00 00 00];

最后编译一下dtb，通过nfs文件系统把dtb文件拷贝到开发板 /boot 目录下就行了，注意一下名字不要弄错了。最后再烧写一下u-boot。开机就能看效果了！

u-boot打印:

进入系统之后 ifconfig -a:

大功告成！

最后再罗嗦两句，第一个就是我是没钱买带TF卡版本的，所以我只有EMMC，然而用 mfg_tool 烧写EMMC的时候默认是 u-boot、kernel、dtb、rootfs 一起烧写的。然后这里只需要烧写 u-boot ，咨询了一下群里的老师，老师让修改一下烧写工具目录下的 ./Profiles/Linux/OS Firmware/ 里的 ucl2.xml 就行了。接下来查了一下资料，只需要删除一部分命令就行了:

大概就是把红色框框里面的东西删掉就OK了。具体语法不详细赘述了。

我把修改好的文件贴上来:

1. <!--

2. * Copyright (C) 2012, Freescale Semiconductor, Inc. All Rights Reserved.

3. * The CFG element contains a list of recognized usb devices.

4. * DEV elements provide a name, class, vid and pid for each device.

5. *

6. * Each LIST element contains a list of update instructions.

7. * "Install" - Erase media and install firmware.

8. * "Update" - Update firmware only.

9. *

10. * Each CMD element contains one update instruction of attribute type.

11. * "pull" - Does UtpRead(body, file) transaction.

12. * "push" - Does UtpWrite(body, file) transaction.

13. * "drop" - Does UtpCommand(body) then waits for device to disconnect.

14. * "boot" - Finds configured device, forces it to "body" device and downloads "file".

15. * "find" - Waits for "timeout" seconds for the "body" device to connect.

16. * "show" - Parse and show device info in "file".

17. -->

20. <UCL>

21. <CFG>

22. <STATE name="BootStrap" dev="MX6SL" vid="15A2" pid="0063"/>

23. <STATE name="BootStrap" dev="MX6D" vid="15A2" pid="0061"/>

24. <STATE name="BootStrap" dev="MX6Q" vid="15A2" pid="0054"/>

25. <STATE name="BootStrap" dev="MX6SX" vid="15A2" pid="0071"/>

26. <STATE name="BootStrap" dev="MX6UL" vid="15A2" pid="007D"/>

27. <STATE name="BootStrap" dev="MX7D" vid="15A2" pid="0076"/>

28. <STATE name="BootStrap" dev="MX6ULL" vid="15A2" pid="0080"/>

29. <STATE name="Updater" dev="MSC" vid="066F" pid="37FF"/>

30. </CFG>

34. <LIST name="SDCard" desc="Choose SD Card as media">

35. <CMD state="BootStrap" type="boot" body="BootStrap" file ="firmware/u-boot-imx6ul%6uluboot%_sd.imx" ifdev="MX6UL">Loading U-boot</CMD>

36. <CMD state="BootStrap" type="boot" body="BootStrap" file ="firmware/u-boot-imx6ul%lite%%6uluboot%_sd.imx" ifdev="MX6ULL">Loading U-boot</CMD>

38. <CMD state="BootStrap" type="load" file="firmware/zImage" address="0x12000000"

39. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6Q MX6D">Loading Kernel.</CMD>

40. <CMD state="BootStrap" type="load" file="firmware/zImage" address="0x80800000"

41. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6SL MX6SX MX7D MX6UL MX6ULL">Loading Kernel.</CMD>

43. <CMD state="BootStrap" type="load" file="firmware/zImage-imx6ul-%6uldtb%%ldo%.dtb" address="0x83000000"

44. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6UL">Loading device tree.</CMD>

45. <CMD state="BootStrap" type="load" file="firmware/zImage-imx6ul%lite%-%6ulldtb%%ldo%.dtb" address="0x83000000"

46. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6ULL">Loading device tree.</CMD>

49. <CMD state="BootStrap" type="jump" > Jumping to OS image. </CMD>

52. <!-- create partition -->

53. <CMD state="Updater" type="push" body="send" file="mksdcard.sh.tar">Sending partition shell</CMD>

54. <CMD state="Updater" type="push" body="$ tar xf $FILE "> Partitioning...</CMD>

55. <CMD state="Updater" type="push" body="$ sh mksdcard.sh /dev/mmcblk%mmc%"> Partitioning...</CMD>

57. <!-- burn uboot -->

58. <CMD state="Updater" type="push" body="send" file="files/u-boot-imx6ul%6uluboot%_sd.imx" ifdev="MX6UL">Sending u-boot.bin</CMD>

59. <CMD state="Updater" type="push" body="send" file="files/u-boot-imx6ul%lite%%6uluboot%_sd.imx" ifdev="MX6ULL">Sending u-boot.bin</CMD>

61. <CMD state="Updater" type="push" body="$ dd if=/dev/zero of=/dev/mmcblk%mmc% bs=1k seek=768 conv=fsync count=8">clear u-boot arg</CMD>

62. <CMD state="Updater" type="push" body="$ dd if=$FILE of=/dev/mmcblk%mmc% bs=1k seek=1 conv=fsync">write u-boot.bin to sd card</CMD>

64. <CMD state="Updater" type="push" body="$ while [ ! -e /dev/mmcblk%mmc%p1 ]; do sleep 1; echo \"waiting...\"; done ">Waiting for the partition ready</CMD>

65. <CMD state="Updater" type="push" body="$ mkfs.vfat /dev/mmcblk%mmc%p1">Formatting rootfs partition</CMD>

66. <CMD state="Updater" type="push" body="$ mkdir -p /mnt/mmcblk%mmc%p1"/>

67. <CMD state="Updater" type="push" body="$ mount -t vfat /dev/mmcblk%mmc%p1 /mnt/mmcblk%mmc%p1"/>

69. <!-- burn zImage -->

70. <CMD state="Updater" type="push" body="send" file="files/zImage">Sending kernel</CMD>

71. <CMD state="Updater" type="push" body="$ cp $FILE /mnt/mmcblk%mmc%p1/zImage">write kernel image to sd card</CMD>

73. <!-- burn dtb -->

74. <CMD state="Updater" type="push" body="send" file="files/zImage-imx6ul-%6uldtb%%ldo%.dtb" ifdev="MX6UL">Sending Device Tree file</CMD>

75. <CMD state="Updater" type="push" body="send" file="files/zImage-imx6ul%lite%-%6ulldtb%%ldo%.dtb" ifdev="MX6ULL">Sending Device Tree file</CMD>

77. <CMD state="Updater" type="push" body="$ cp $FILE /mnt/mmcblk%mmc%p1/imx6ul-%6uldtb%.dtb" ifdev="MX6UL">write device tree to sd card</CMD>

78. <CMD state="Updater" type="push" body="$ cp $FILE /mnt/mmcblk%mmc%p1/imx6ul%lite%-%6uldtb%.dtb" ifdev="MX6ULL">write device tree to sd card</CMD>

80. <!-- burn m4 demo bins-->

81. <CMD state="Updater" type="push" body="$ umount /mnt/mmcblk%mmc%p1">Unmounting vfat partition</CMD>

83. <!-- burn rootfs -->

84. <CMD state="Updater" type="push" body="$ mkfs.ext3 -F -j /dev/mmcblk%mmc%p2">Formatting rootfs partition</CMD>

85. <CMD state="Updater" type="push" body="$ mkdir -p /mnt/mmcblk%mmc%p2"/>

86. <CMD state="Updater" type="push" body="$ mount -t ext3 /dev/mmcblk%mmc%p2 /mnt/mmcblk%mmc%p2"/>

88. <CMD state="Updater" type="push" body="pipe tar -jxv -C /mnt/mmcblk%mmc%p2" file="files/rootfs_nogpu.tar.bz2" ifdev="MX6UL MX7D MX6ULL">Sending and writting rootfs</CMD>

89. <CMD state="Updater" type="push" body="frf">Finishing rootfs write</CMD>

90. <CMD state="Updater" type="push" body="$ umount /mnt/mmcblk%mmc%p2">Unmounting rootfs partition</CMD>

91. <CMD state="Updater" type="push" body="$ echo Update Complete!">Done</CMD>

92. </LIST>

94. <LIST name="eMMC" desc="Choose eMMC as media">

96. <CMD state="BootStrap" type="boot" body="BootStrap" file ="firmware/u-boot-imx6ul%lite%%6uluboot%_ddr%ddrsize%_emmc.imx" ifdev="MX6ULL">Loading U-boot</CMD>

98. <CMD state="BootStrap" type="load" file="firmware/zImage" address="0x80800000"

99. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6SL MX6SX MX7D MX6UL MX6ULL">Loading Kernel.</CMD>

101. <CMD state="BootStrap" type="load" file="firmware/%initramfs%" address="0x83800000"

102. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6SL MX6SX MX7D MX6UL MX6ULL">Loading Initramfs.</CMD>

105. <CMD state="BootStrap" type="load" file="firmware/zImage-imx6ul%lite%-%6uldtb%-emmc.dtb" address="0x83000000"

106. loadSection="OTH" setSection="OTH" HasFlashHeader="FALSE" ifdev="MX6ULL">Loading device tree.</CMD>

108. <CMD state="BootStrap" type="jump" > Jumping to OS image. </CMD>

111. <!-- create partition -->

112. <CMD state="Updater" type="push" body="send" file="mksdcard.sh.tar">Sending partition shell</CMD>

113. <CMD state="Updater" type="push" body="$ tar xf $FILE "> Partitioning...</CMD>

114. <CMD state="Updater" type="push" body="$ sh mksdcard.sh /dev/mmcblk%mmc%"> Partitioning...</CMD>

116. <!-- burn uboot -->

117. <CMD state="Updater" type="push" body="$ dd if=/dev/zero of=/dev/mmcblk%mmc% bs=1k seek=768 conv=fsync count=8">clear u-boot arg</CMD>

118. <!-- access boot partition -->

119. <CMD state="Updater" type="push" body="$ echo 0 > /sys/block/mmcblk%mmc%boot0/force_ro">access boot partition 1</CMD>

122. <CMD state="Updater" type="push" body="send" file="files/u-boot-dtb.imx" ifdev="MX6ULL">Sending u-boot.bin</CMD>

124. <CMD state="Updater" type="push" body="$ dd if=$FILE of=/dev/mmcblk%mmc%boot0 bs=512 seek=2">write U-Boot to sd card</CMD>

125. <CMD state="Updater" type="push" body="$ echo 1 > /sys/block/mmcblk%mmc%boot0/force_ro"> re-enable read-only access </CMD>

126. <CMD state="Updater" type="push" body="$ mmc bootpart enable 1 1 /dev/mmcblk%mmc%">enable boot partion 1 to boot</CMD>

127. </LIST>

128. </UCL>

注意！注意！注意！我这里是使用的EMMC哈！

然后说第二点，通过上面的修改，两个网卡的MAC地址都应该是搞定了的。然而这里面还有一种情况，就是 u-boot 的环境变量里面设置了 ethaddr 变量，这种情况下u-boot会去解析设备树之后把我们修改好的值替换成这个变量的值。当然这里也是可以解决的，解决方法就在上文中提到的另外一篇blog里面写得很详细的，因为我实在是不想打字了，抱歉了。

最后依照惯例还是应该要说一下，本人毕竟水平有限。有什么问题就联系我吧！

imx6ull使用Unique ID配置网卡MAC地址 - 灰信网（软件开发博客聚合）