Obtaining u-boot source code for mpc5121e

[bbjh1]

I am trying to install LTIB on my host machine (Linux) for mpc5121e. I found the iso image for the bsp (20090603). I installed it and configured it but for some reason I can't find any u-boot folder inside /rpm/BUILD. Does anyone know why?

Thank you.

[moidom]

Hi,

Take a look at: http://www.freescale.com/files/32bit/doc/app_note/AN3220.pdf

./ltib -p u-boot-1.2.3-mpc5121ads.spec -m prep        -> extract

./ltib -p u-boot-1.2.3-mpc5121ads.spec -m scbuild   -> compile

[abartky · Accepted solution]

bbjh1,

FYI.  Besides app note 3220 on U-boot, if you haven't checked it out already, there is lots of additional information at http://www.bitshrine.org which is the official open source site for LTIB.

In particular, I think you may find the FAQ section there.  Check out: http://www.bitshrine.org/ltib/documentation-LtibFaq and in particular take a look at the section on "Packages".  That gives most of the commands you need to know when working with LTIB source packages of which U-boot is one of the packages in the Freescale Linux distributions.

That section also gives guidlines on how to create you own package to add to the system. 

Hope this helps.

Best regards,

Alan

[bbjh1]

Moidom,

Thank you for your reply. It was very helpful.

I am facinf an issue and I hope you can help me. For some reason, whenever I try to boot the board via nfs (run net_nfs) I am getting an error : Wrong Kernel Image! and Bad CRC.

I am using mpc5121e on ADS512101 board rev. 3.2. Do you know which BSP I should install? I installed the one found on freescale.com MPC512xADS_20090603. Is this the right file?

Thank you in advance.

bbjh1

[moidom]

Hi,

>>error : Wrong Kernel Image! and Bad CRC.

- First thing I should do is to update u-boot: place a compiled u-boot.bin in your tftpfolder and type

=>run load
=>run update

-Second I would do is be sure that u-boots environments var are setted right (in porting linux app note are the right values)

>> am using mpc5121e on ADS512101 board rev. 3.2.

I am using LTIB too but with a rev 4.1 file.

[bbjh1]

Hi moidom,

Thank you so much for your reply. I want to ask you if it is safe to update the u-boot because I read that this is a dangerous process and I might loose u-boot loader on the board.

Thank you!

[abartky]

bbjh1,

If you do not have all the tools you need for developing/debugging U-boot (including a full compiler set and also a Hardware JTAG Pod/debugger set so you can burn Flash images directly without using TFTP).  Then you should leave U-boot alone as you can make the board useless if you screw up.  Trust me, I've done that and was really glad that I had the Codewarrior USB tap to reburn my board to bring it back to life.

If you goal is to write simple programs rather then bringing up full blown linux, then the better method is to leave U-boot alone and  instead, write code to locate to an area of flash not used by U-boot or Linux (assuming you are running Linux), burn that area of flash using U-boot TFTP to transfer the binary image and U-boot to burn it to flash and then use U-boot to jump to that location and start executing.  That is a method I've used in the past and it works quite well.

Having said that, if you are really serious about doing low level programming and not just Linux applications, you really do need to invest in a USB TAP or other Hardware debugger to get your job done.

Hope this helps.

Best regards,

Alan

[bbjh1]

Thank you guys! I was able to solve the problem....I have mounted the jffs2 file system image on the board's flash memory and I can run jffs2boot normally.

Thank you again.

Now it is time to figure out how to access the memory so the first thing I need to know is how to turn on the LED using only the apptrk connection ( I can't afford buying the USB tap).

bbjh1

[bbjh1]

Hey Alan,

Thank you for ur reply and ur help. I was able to boot the board using nfs. Now I am trying to deploy jffs2 image. I followed all the steps but whenever I try to run jffs2boot nothing happens!!

Is there any steps I can follow to use u-boot to load c code and try to, for example, turn on the LEDs on the board?

Thank you again for the help.

bbjh1