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U-boot is an open source bootloader. This post is here because I had a problem with U-boot where I couldn't update it using ethernet.

It's not that difficult to use serial line for u-boot upgrading, as long as you have a "working" u-boot flashed in your board, you can always use loady or loadb to download binary image into your board's RAM.

For achieving this, we'll need:

• A target board with u-boot running;
• A new u-boot binary;
• Minicom;
• a serial cable.

Let's do it, step by step. By the way, I'm using an OMAP 1710 H3 board, so be aware memory offsets in your board may change.

1. Attach a serial cable to your board;
2. Open minicom by issuing:

 $ minicom

in a terminal;

3. Start your board and stop u-boot's autoboot;
4. run:

 # loady 10000000 115200

at u-boot's prompt;

5. Issue CTRL+s at U-boot and choose ymodem
6. Wait until the image is loaded into memory
7. After the image is loaded in RAM memory, it'll return you the amount of transfered bytes.

8.  # protect off 00000000 0001ffff

9.  # era 00000000 0001ffff

10.  # cp.b 0x10000000 0x00000000 size_in_hex

11.  # protect on 00000000 0001ffff

And that's all. Restart your board and you'll have a new U-boot flashed.

This entry was posted on Thursday, December 6th, 2007 at 22:34 and is filed under Linux, U-boot. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.