i.MX ProcessorsのトピックRe: Load u-boot with JTAG

Load u-boot with JTAG

rajtantajtan — Tue, 09 Jul 2013 06:24:05 GMT

Hi,

I have a Segger J-Link and openocd and got a connection running with my imx28evk-board.

Now I want to load U-boot to memory with JTAG so I can run it directly and not have to read it from sdcard, however I haven't found any documentation on how to do this. I have moved the switches to JTAG boot mode and tried to follow something like this guy did https://community.nxp.com/message/307083

but the only output I got from my evk-board was this:

U-Boot 2013.07-rc2-00023-ga544ead (Jul 04 2013 - 15:30:51)

CPU:   Freescale i.MX28 rev1.2 at 454 MHz

BOOT: Û_©ÌÚ^)×

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            `m

ÆãäÉê$1³ÿbdè»¼vþ¾_^Òo?+k

ÃÊôã»ÆZPÜxÿ¥

¸'pfE¾¤à®zÇt¹5Ù,HíÈ&>©ãsë¢ö]®mïÃþòÏÛk=-_ÎÙ®|~   £Gô'?J;î-

                                             R¯CabsRØäÿkèDk2:Gfø^ÂùµüÄù¾

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As you may notice I have compiled mainline U-boot and it seems to start but then turns into random crap. Do you have any idea of what I'm doing wrong here?

Re: Load u-boot with JTAG

sinanakman — Tue, 09 Jul 2013 14:34:33 GMT

Is this perhaps a baudrate issue ? You are using your terminal emulator with a baudrate, then u-boot starts and set it to another value and your terminal emulator stays with the older setting. Try changing the baudrate of your terminal emulator or find out what u-boot setting is. Just an idea ..

Re: Load u-boot with JTAG

rajtantajtan — Wed, 10 Jul 2013 05:21:18 GMT

After I done my homework I found out that u-boot should not be loaded directly to RAM with JTAG. u-boot should be loaded from nand/nor/sd-card.

Re: Load u-boot with JTAG

fabio_estevam — Wed, 10 Jul 2013 18:08:35 GMT

Please follow the steps from:

git.denx.de Git - u-boot.git/blob - doc/README.mx28_common

Re: Load u-boot with JTAG

rajtantajtan — Thu, 11 Jul 2013 07:56:50 GMT

Yes, there is very good documentation on how to make mx28 boot in u-boot's documentation.

Re: Load u-boot with JTAG

cono — Tue, 31 Mar 2015 17:13:41 GMT

Hi rajtantajtan,

it is no problem to load U-Boot into RAM via JTAG. Just load and execute i.MX28's U-Boot SPL ELF before normal U-Boot ELF. After SPL was execiuted DDR is initialized and normal U-Boot ELF could be loaded to DDR.

SPL ELF could be found in subfolder SPL of U-Boot source tree.

Regards,

Christoph