[vc_row][vc_column width=”1/1″][vc_column_text]PcDuino embedded linux development :Modifcation u-boot(—)

u-boot is kind of boot loader,boot loader .This small program with before the run of operating system kernel.Complete this small program,We can be initializes the hardware equipment、and the establishment of memory map,Thus the system hardware and software enviroment to a proper state.Uaually the boot loader is heavily dependent on hardware implementation,Especially in the embedded warld.So in the embedded world to establish a general boot loader is almost impossible.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column width=”1/1″][vc_tour][vc_tab title=”Offcial u-boot introduction” tab_id=”1387353144-1-87″][vc_column_text]Official provide of u-boot can be perfect boot the kernel,but if used to study the embedded Linux development is not appropriate. The reason was that official provide u-boot without the network configuration information.The best check way serial port connection when system start debugging .when the computer have 3 seconds with stopping that you must enter any buttons,And then perform.

Ping LAN gateway

It will prompt haven’t this Ping of command,also no tftp ,nfs related commands,So what do you do.I will tell you best ways.Then must modified source to git,Pls directly download and used.

Specific modification process is:

Host machine: ubuntu-12.04(64位)

Target machine：pcDuino

Cross compiler: arm-linux-gnueabihf-gcc (安装sudo apt-get install  g++-arm-linux-gnueabihf)

Download u-boot sound code:

git clone https://github.com/linux-sunxi/u-boot-sunxi.git

After download, view the branch

pillar@monster:~/study/kernel/u-boot-sunxi/u-boot-sunxi$ git branch -a

* sunxi

  remotes/origin/HEAD -> origin/sunxi

  remotes/origin/lichee-dev

  remotes/origin/lichee-dev-a20

  remotes/origin/lichee/lichee-dev

  remotes/origin/lichee/lichee-dev-ICS

  remotes/origin/lichee/lichee-dev-mmc

  remotes/origin/old/sunxi-current

  remotes/origin/sunxi

  remotes/origin/wip/a20

You can see U-boot afficial website to download with have a lot of branch,So I will explain some problem:

Lichee-dev: support nand and TF card,but does not support network now pcDuino official release;

Sunxi and sunxi – current: support TF card, also support network, but does not support nand boot;
Here can only be changed in the official version, will git to switch to the official version.

git  checkout  lichee-dev

Before you modify the source code,I will tell you which first open.

NAND open is ROM->Boot0->boot1->uboot->linux kernel

SD open is ROM->spl->uboot->linux kernel

Allwinner have some ways:

First of all, the hardware connection according to the way

PcDuino < – > serial port < – > PC USB

PcDuino < – > OTG < – > PC USB

Open the serial debugging assistants, such as putty or within xshell tools., the system is powered on and then hold down the “1” key on the computer, when the system will automatically install the driver for the first time,finally the pop-up nanda partition

follow  picture:

.

You can see the uImage, u – the boot in Linux folder, need only will you develop uImage and u – the boot can be copied to the corresponding position.

Here is how to modify the u – the boot, and then introduces an effective method.

[/vc_column_text][/vc_tab][vc_tab title=”Compile configuration u-boot ” tab_id=”1387353144-2-92″][vc_column_text]Official website to download support pcDuino u – the boot, not called pcDuino, it’s called a10 – evb, here don’t like to do the corresponding modification.

vim boards.cfg

189 sun4i                        arm         armv7       pcDuino             allwinner      sunxi       sun4i:SUNXI_EMAC

190 sun4i_sd                     arm         armv7       a10-evb             allwinner      sunxi       sun4i:SD_UART

191 sun5i_a12                    arm         armv7       a12-evb             allwinner      sunxi

192 sun5i_a13                    arm         armv7       a13-evb             allwinner      sunxi

193 sun5i_a13_sd                 arm         armv7       a13-evb             allwinner      sunxi

In 189 lines of position changes, then add to configure the network in sun4i: SUNXI_EMAC, in source level plus pcDuino board support package.

pillar@monster:~/study/kernel/u-boot-sunxi$ cd board/allwinner/

a10-evb/ a13-evb/ pcDuino/

Is the a10 – evb copy into pcDuino, enter pcDuino, modify the inside of the file named pcDuino. C, and then modify the Makefile.

29 COBJS   := pcDuino.o

Modify pcDuino

160 #ifdef CONFIG_DISPLAY_BOARDINFO

161 int checkboard(void)

162 {

163     puts(“Board: pcDuino\n”);

164     return 0;

165 }

166 #endif

Began to compile under the u – the boot

 cd u-boot-sunxi

 mkdir build

 make distclean CROSS_COMPILE=arm-linux-gnueabihf-

 make sun4i_config CROSS_COMPILE=arm-linux-gnueabihf-  O=build

 make CROSS_COMPILE=arm-linux-gnueabihf- O=build

After the compilation on pcDuino run, how to do ?

scp u-boot.bin Ubuntu@pcDuino的IP：/home/ubuntu/

sudo mount    /dev/nanda   /mnt

sudo  chmod u+w linux

sudo  cd linux

sudo  rm  u-boot.bin

sudo  cp  /home/Ubuntu/u-boot.bin  .

sudo  cd ..

sudo   chmod u-w linux

sudo   reboot

Stay in 3 seconds after restart stop position

This u-boot also does not support  network  function ,Just simply modify the board of name,

[/vc_column_text][/vc_tab][vc_tab title=”Modify support network function” tab_id=”1387358067022-2-1″][vc_column_text]First see the sunxi-current with inside source code, found that he has been in the boards initialization of the network, we can start from here

vim ./arch/arm/cpu/armv7/sunxi/board.c  #add

157 #if defined(CONFIG_SUNXI_EMAC)

158 /*

159  * Initializes on-chip ethernet controllers.

160  * to override, implement board_eth_init()

161  */

162 int cpu_eth_init(bd_t *bis)

163 {

164     sunxi_emac_initialize(bis);

165

166     return 0;

167 }

168 #endif

Then sunxi – the inside of the current network card driver copy into the lichee – dev

cp ~/u-boot/drivers/net/sunxi_emac.c     drivers/net/

Modify  Makefile

vim drivers/net/Makefile      #add

29 COBJS-$(CONFIG_SUNXI_EMAC) += sunxi_emac.o

Save after compiling, there must be some wrong here, now you only need to solve these errors, you can complete the u – the boot.The following is my all changes:

https://github.com/Pillar1989/sunxi-u-boot/blob/lichee-dev/diff.log

And ++ meaning add then – meaning delete

So you can see my git warehouse https://github.com/Pillar1989/sunxi-u-boot

Download test

sun4i# tftp 0×46000000 uImage

Using emac device

TFTP from server 192.168.2.3; our IP address is 192.168.2.22

Filename ‘uImage’.

Load address: 0×46000000

Loading: #################################################################

          #############################################

done

Bytes transferred = 1611552 (189720 hex)

sun4i#tftp 0×49000000 dts/sun4i-a10-cubieboard.dtb

Using emac device

TFTP from server 192.168.2.3; our IP address is 192.168.2.22

Filename ‘dts/sun4i-a10-cubieboard.dtb’.

Load address: 0×49000000

Loading: #

done

Bytes transferred = 7940 (1f04 hex)

sun4i#bootm 0×46000000 – 0×49000000

## Booting kernel from Legacy Image at 46000000 …

   Image Name:   Linux-3.12.0-10089-gf16892f-dirt

   Created:      2013-11-19  12:28:56 UTC

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    1611488 Bytes = 1.5 MiB

   Load Address: 40008000

   Entry Point:  40008000

   Verifying Checksum … OK

   Loading Kernel Image … OK

OK

Starting kernel …

Ending everyone see the perfect support TFTP download,,Next time I will explain what’s TFTP server and nfs server,etc.[/vc_column_text][/vc_tab][/vc_tour][/vc_column][/vc_row]