Save U-Boot environment to SPI

VIM3
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Hello, I am using SPI U-Boot. Would it be safe to build U-Boot with an option to store env to SPI, instead of a FAT partition? That is, is it safe to enable CONFIG_ENV_IS_IN_SPI_FLASH in U-Boot build config?

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Yes ! why not ? its works fine

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Nice, thanks! I just wanted to ask first as it’s my first time messing with bootloaders :smile:

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@hyphop Uh I just figured U-Boot images are built from your repo here: https://github.com/krescue/khadas-uboot
Since the scripts are highly automated, how do I edit the U-Boot config before it gets built?

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i will try to check tomorrow :wink:

1 Like
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Thank you! I tried to figure out how to get saveenv runing myself today by playing around with the board to save some U-Boot env variables regarding usb boot and this is a quick report:

  1. Legacy U-Boot in a Ubuntu EMMC image can run saveenv, but can’t do USB boot
  2. Mainline U-Boot can do USB boot, but I can’t saveenv. I have three ideas so far that I think could work, but I don’t know how to do any of these three things:
  • Create a FAT EMMC partition after flashing U-Boot mainline, or
  • Build U-Boot mainline with support for saveenv to SPI, or
  • Build U-Boot with a modified environment

I hoped to figure something out so I don’t have to bug you guys, but as my knowledge ends here, unfortunately so do my attempts at saveenv with mainline U-Boot, and I await your kind assistance @hyphop :smile:

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same can boot but need change default uboot env

Mainline U-Boot can do USB boot, but I can’t saveenv . I have three ideas so far that I think could work, but I don’t know how to do any of these three things:

our mainline uboot variant can save env but need fat partition

PS: tell me what you need from uboot ?

UPDATE: https://dl.khadas.com/Firmware/uboot/mainline/Khadas.UBOOT.mainline.emmc.kresq - was updated now with fat partition (no need to create it )

2 Likes
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AMAZING, thank you! That’s exactly what I needed!

Well, I’ve got a problem booting from a USB HDD where U-Boot recognizes it as a USB device, but not as a storage device, and skips it. If I run the command prompt and just do usb reset, that takes care of it - U-Boot then recognizes it as a storage device, and can boot from it. I posted some logs etc. to the forum, and then after playing around some more I posted an issue to GitHub, but to the wrong repo (this GitHub issue is more complete than the forum post).

Anyway, I suspect the problem is simply that the disk hasn’t spun up or something like that, so I plan on adding a boot delay, and, if needed, a usb reset to the USB boot command. I’ll try playing around now that I can save env to a FAT partition, thanks again!

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Okay, I got it working by modifying preboot - I suspect there is a bug in U-Boot. To repeat, U-Boot sees my USB HDD, but doesn’t recognize it as a storage device, unless I do usb reset.

Default preboot, which fails:

run load_logo; usb start; kbi init; sleep 1;

Setting sleep 10; before usb start doesn’t work, so it’s not related to HDD powerup or something like that. Strictly usb reset is needed after usb start, so there is something happening differently between usb start and usb start; usb reset, when there shouldn’t be any difference. I thought kbi init might need to be run before usb start, so I tried it, and it still failed.

So usb start; usb reset; is the only thing that works - this is my current preboot:

run load_logo; usb start; kbi init; sleep 1; usb reset; sleep 1;

So my system works and I’m very happy, but it’s still just a workaround and I am pretty sure there’s some kind of bug in U-Boot (and/or its USB subsystem) that’s causing it. If I can be of any help, please let me know! :smile: Relevant logs are here. Thanks for the help!

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tell me more about your USB HDD - model etc … , and power supply and which usb port used !
and we can test and improve it !!!

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  • USB HDD: ID 125f:a83a A-DATA Technology Co., Ltd. HD330 (1TB, USB3)
  • Power supply: 9VDC, 1.67A; or 5VDC 2A
  • USB ports: happens on both, but I’m using the USB3 900 mA port (KBI set to USB3)

I don’t think it’s the power supply because a 10 second boot delay would’ve likely given a weak PSU more than enough time to level out its voltage. On the other hand, nothing except a usb reset helps.

However, that’s just my educated guess, and not a test! I have three things I’ll do in order to rule out the power supply:

  1. I ordered an official Khadas 24W power supply plus USB-C cable directly from the Khadas AliExpress store two weeks ago, will test as soon as it arrives. If it doesn’t in the next few days, then…:
  2. I’ll hook up an oscilloscope to the power supply line and see what happens to the power supply voltage during the boot process.
  3. If it has dips, I’ll hook up a beefy capacitor across the power supply lines and see if that helps.