Colibri t20 boot from sd card

Technical Support
1

Colibri t20 v1.2 512mb.

Can I boot the operating system from an SD card on a Colibri T20? The Linux kernel has been successfully compiled. How do I make the SD card bootable?

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

Yes, you can boot the Colibri T20 from an SD card (1). The module supports this through bootstrap pin configuration.

Bootstrap Configuration for SD Card Boot

To enable SD card booting on the Colibri T20, you need to configure the bootstrap pins as follows (1):

  • X1 Pin #: 173, 175, 177, 179
  • Status: All pulled low with 680 Ohm resistors
  • Boot Device: MMC/SD Card
  • Comment: These pins are internally pulled up with 3.3kOhm (1)

By default, the Colibri T20 boots from internal Flash Memory when these pins are open or pulled high (1).

Power Consumption Consideration

If you want to minimize power consumption, you can activate the pull-down resistors only at boot time (1).

SD Card Preparation

The documentation mentions that you need to format the SD Card with a special tool to use it as a boot device (1). However, the specific formatting procedure isn’t detailed in the available sources.

Recovery Mode Alternative

If your system doesn’t boot from internal Flash Memory anymore, you can also use recovery mode to flash a new image. The Colibri T20 supports recovery mode through hardware mechanisms or bootloader commands (2).

For more detailed information about SD card formatting and bootable image creation, you may need to consult additional Toradex documentation or contact support through the Community or GitHub.

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3

The answer was not entirely satisfactory. I booted from the SD card. I connected X1 Pin #: 173, 175, 177, 179 to ground. How to make a bootable SD card?

4

Great! Since you’ve successfully configured the bootstrap pins for SD card boot, let me help you create a bootable SD card for your Colibri T20.

SD Card Requirements for Windows CE

For Windows CE on the Colibri T20, the SD card must meet specific requirements (1):

  • Format: SDCard FAT16 formatted (1)
  • Compatibility: SDHC is not supported (1)
  • Image location: Image has to be located in the root folder (1)
  • Image name: Image has to be named “nk.bin” (1)

Bootloader Configuration

To enable SD Card boot in the bootloader, you need to edit the Config Block (1):

boot.dltype=2           (Download via: 0=Ethernet,1=USBC,2=SDCard)

(1)

Boot Options

Once configured, you have two options in the Bootloader Menu (1):

  • Option ‘d’: Loads the Windows CE image into RAM and jumps to this image (1)
  • Option ‘f’: Saves the Windows CE image to Flash first and launches afterwards (1)

For Linux Systems

If you’re working with Linux instead of Windows CE, the process is different. For modern Toradex modules, you would typically need (2):

  • A FAT partition to store the kernel image and device trees (2)
  • An ext4 partition to store the rootfs (2)

However, since you mentioned you have a compiled Linux kernel, you’ll need to ensure it’s properly formatted for the Colibri T20’s boot requirements.

Next Steps

Since the specific Linux SD card creation process for Colibri T20 isn’t fully detailed in the available sources, I recommend checking these potentially useful sources:

Would you like a general answer based on my knowledge instead?

Best regards, Toradex AI Assistant.

Did you like my answer? :+1: :-1:

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.

5

I compiled Linux on BSP version 2.8. I need it to boot from an SD card.

6

Colibri T20 modules are fused to boot from internal flash, so the bootloader must be started from internal flash. Once the bootloader is running, it can boot the OS from any available storage, including an SD card, if configured properly. We use U-Boot, which you can flash from the legacy images available here.

7

Are there instructions for preparing an SD card to start the system?

8
9

I tried to follow the instructions. But the system won’t boot from the SD card. Maybe there are more detailed instructions adapted for Colibri T20?