Loading Barebox to RAM

Loading Barebox to RAM

[Patrick Schneider]

Hey guys,
I have a question about a way of "emergency flashing" the device.
So I have a fully operational linux system with barebox as bootloader. In production environment I have no access to the serial console but I have a USB OTG port.
For security reasons I don't want USB active in my "normal" barebox environment, so it's off by config.
For support, to gain access to a barebox and bootloader functionality is there a way to load another barebox (with usb active) from linux userspace into RAM and start/reboot into that?
Have a nice weekend!
Regards,
Patrick

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Re: Loading Barebox to RAM

[Oleksij Rempel]

Hi,

Am 02.03.19 um 13:49 schrieb Patrick Schneider:
> Hey guys,
> I have a question about a way of "emergency flashing" the device.
> So I have a fully operational linux system with barebox as bootloader. In production environment I have no access to the serial console but I have a USB OTG port.
> For security reasons I don't want USB active in my "normal" barebox environment, so it's off by config.
> For support, to gain access to a barebox and bootloader functionality is there a way to load another barebox (with usb active) from linux userspace into RAM and start/reboot into that?
> Have a nice weekend!

Let me rephrase: you disabled every thing in a bootloader which can be
accessed only locally and provided functional to nuke complete system
from linux which can be accessed locally and remotely?
I assume, it would make sense to review the thread model of this project.

Any way. "is it possible to run barebox from linux", the answer would
be: theoretically it should be possible to do it from kexec. I never
tried it before.
-- 
Regards,
Oleksij

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Re: Loading Barebox to RAM

[Sascha Hauer]

On Sat, Mar 02, 2019 at 03:36:51PM +0100, Oleksij Rempel wrote:
> Hi,
> 
> Am 02.03.19 um 13:49 schrieb Patrick Schneider:
> > Hey guys,
> > I have a question about a way of "emergency flashing" the device.
> > So I have a fully operational linux system with barebox as bootloader. In production environment I have no access to the serial console but I have a USB OTG port.
> > For security reasons I don't want USB active in my "normal" barebox environment, so it's off by config.
> > For support, to gain access to a barebox and bootloader functionality is there a way to load another barebox (with usb active) from linux userspace into RAM and start/reboot into that?
> > Have a nice weekend!
> 
> Let me rephrase: you disabled every thing in a bootloader which can be
> accessed only locally and provided functional to nuke complete system
> from linux which can be accessed locally and remotely?
> I assume, it would make sense to review the thread model of this project.
> 
> Any way. "is it possible to run barebox from linux", the answer would
> be: theoretically it should be possible to do it from kexec. I never
> tried it before.

I tried it on ARM and it used to work. Of course you need a barebox that
doesn't try to bringup the SDRAM you are currently running at, but most
code in barebox tests the PC being outside SDRAM before setting it up.

Sascha

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