Question about environment variables

Discussion about U-Boot and the kernel.

Question about environment variables

Postby woody » Mon May 27, 2013 9:37 pm

I've been trying everything I can to try to get my Pogoplug V2 to reboot successfully from a USB hard drive. Right now, I have to pull the power cord every time to get it to reboot. Also, recently, the Pogo failed to boot up after a power failure.

While I'm experimenting, I don't want to hose up my system so that it won't boot up at all. Is there a way to back up and restore some default environmental variables? Or else, is there a way that I can edit my USB drive in another PC to fix the environment variables, in case I break something?
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Re: Question about environment variables

Postby WarheadsSE » Tue May 28, 2013 3:18 am

Generally, the entire configuration is stored in /etc and your home directory (/root or /home/username)
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Re: Question about environment variables

Postby woody » Tue May 28, 2013 11:27 am

$this->bbcode_second_pass_quote('WarheadsSE', 'G')enerally, the entire configuration is stored in /etc and your home directory (/root or /home/username)


Does that include the U-boot variables set by fw_setenv? Where are those stored?
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Re: Question about environment variables

Postby WarheadsSE » Tue May 28, 2013 4:15 pm

Those are stored in the nand
Last edited by WarheadsSE on Tue May 28, 2013 4:15 pm, edited 1 time in total.
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Re: Question about environment variables

Postby woody » Tue May 28, 2013 4:22 pm

$this->bbcode_second_pass_quote('WarheadsSE', 'T')hose are stored in the nand


That's what I thought. So, now I think I've managed to mess up my environment variable in such a way that I'm unable to boot.

This is what I set:

$this->bbcode_second_pass_code('', 'fw_setenv usb_init "run usb_scan; setenv usb_root LABEL=ROOTFS rw"')

I think that I need to set it back to:

$this->bbcode_second_pass_code('', 'fw_setenv usb_init "run usb_scan"')

So, can anybody suggest a way to get it to boot with the existing setting or else get the environment variable changed back?
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Re: Question about environment variables

Postby woody » Tue May 28, 2013 7:05 pm

Never mind. I figured out that I can boot back into the original "naked" Pogoplug firmware and reset the U-boot variables there. For some reason, I thought that the updated U-boot would now allow me to boot into the old Pogoplug environment, but obviously that's incorrect. Lots to learn about hacking these things!
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