How can I write a u-boot.bin-sdcard to an SD card for Tt1042d4rdb?
Here's what I did:
1. Using Yocto 2.6.1, I've followed:https://www.yoctoproject.org/docs/2.6.1/brief-yoctoprojectqs/brief-yoctoprojectqs.html
2. In local.confg, I've set "MACHINE ??= "t1042d4rdb"
3. I've run "bitbake u-boot"
4. I've run: sudo dd if=tmp/deploy/images/t1042d4rdb/u-boot.bin-sdcard of=/dev/sdb obs=4096 seek=1; sync
5. I've set the dip-switches as per the image below
6. Insert sd-card
7. power up
Expected result: u-boot startup output on the UART1 115200. I'm getting output when I run the factory installed u-boot from NOR flash.
Actual result: no output on serial port
AN12105.pdf tells me: "SD card must be pre-programmed at 0x1000 offset starting with RCW
data, PBI commands, SPL, and U-Boot image."
已解决! 转到解答。
I've discovered that my Ubuntu 18 laptop sometimes fails to write to the SD card. There's no error message, the "sudo dd ..;sync" commands happily completes. However, the SD card is not updated. The fix is to reboot my PC.
Also, if I forget to insert the SD card, the "sudo dd ...;sync" command still completes successfully, which is unfortunate. I'd much prefer an explict error message.
I ran: "sudo dd if=tmp/deploy/images/t1042d4rdb/u-boot.bin-sdcard of=/dev/sdb bs=512 seek=8; sync"
Now it works: it boots from the SD-card.
Thanks!
Q: what's the difference between "bs=512 seek=8" and "bs=4096 seek=1"?