How to download U-boot to RAM with Trace32 ? (iMX28)

[danielyun]

Hello, guys.

Board : iMX28-evk based

Boot Method : NAND flash (Zentel 128MB)

RAM : DDR2 (Zentel 64MB)

We have made a new board revision named ES_01.

Until the WS_02 board, everything works fine.

But, with this new ES_01 board, there's some problem with USB download. (the USB D+/D- path is not working)

So I tried to download U-boot image directly from RAM to NAND flash.

For the first step, I had attached Lauterbach Trace32 to our ES_01 board successfully.

As for the second step, I had initialized the ES_01 board's DDR2 ram.

And then, I've downloaded u-boot binary to 0x41008000 RAM address and Reset the P.C to 0x41008000.

But, whenever I started the u-boot routine, I got this answer by debug UART.

"Undefined Ins0x80508002"

I am stuck up here.

Any advice would be helpful.

[Yuri · Accepted solution]

At first, it makes sense to test memory.
The error message "Undefined Ins" may relate to DDR issue.

You may try the memory test, provided in Community.

https://community.freescale.com/message/375263#375263

https://community.freescale.com/servlet/JiveServlet/download/375692-270338/mem_test.7z.zip

Next, is U-boot start address correct ? Can You see standard ARM startup codes ? 

Have a great day,
Yuri

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[danielyun]

Hello Yuri,

Thanks for your advice.

"The error message "Undefined Ins" may relate to DDR issue." was the key point.

I've read DDR initialization code and I found that there was some wrong instructions

We use Zentel 512Mb DDR2 SDRAM A3R12E40CBF

1) This chip uses A0~A12 addresses

    Data.Set 0x800E0074 %Long 0x0302020A => Data.Set 0x800E0074 %Long 0x0f02020A

2) The DDR has 4 banks

    Data.Set 0x800E007C %Long 0x00010101 => Data.Set 0x800E007C %Long 0x00000101

After changing these two instructions, U-boot works well in DDR2 RAM.

For those who suffers the same problem, I wish this may help.

Thank you again, Yuri