[beagleboard] Re: Is it possible to change boot device 'programmatically'?
Dennis Lee Bieber wrote: > On Wed, 1 Sep 2021 20:06:49 +0100, in gmane.comp.hardware.beagleboard.user > Chris Green wrote: > > >Dennis Lee Bieber > wrote: > >> > >> I'm surprised this post even came through. The beagleboard forum > >> /moved/ to a new web-based-only system (which I have refused to fight with > > > >I suspect this will carry on working. :-) Good! > > > But you and I may be the only ones still monitoring it > > > >OK, thanks, I suspect it may be rather more difficult than I had hoped. > > > >What I'm aiming for is a Pi/BBB type system that can clone itself > >automatically every day or so. That would allow me to have a fairly > >quick to implement backup for my Pi (could justas well be a BBB) that > >provides DHCP/DNS on my LAN. > > Mostly I think folks do that with rsync > https://man7.org/linux/man-pages/man1/rsync.1.html > I use rsync a lot but getting it to copy the right bits across to a target is not a straightforward exercise. I think what one might do is:- Maintain an up to date image somehow (but how) Copy the necessary files for dnsmasq across (again, how to select files) Trying to maintain the whole thing by copying with rsync doesn't seem to me to be a good idea. However, from another mailing list (hurrah!), it has been suggested that docker may be the answer. Run dnsmasq in docker on one system and synchronise its files across to another docker image that you don't run until needed. -- Chris Green · -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/nvf60i-q3fj1.ln1%40esprimo.zbmc.eu.
[beagleboard] Re: Is it possible to change boot device 'programmatically'?
On Wed, 1 Sep 2021 20:06:49 +0100, in gmane.comp.hardware.beagleboard.user Chris Green wrote: >Dennis Lee Bieber >wrote: >> >> I'm surprised this post even came through. The beagleboard forum >> /moved/ to a new web-based-only system (which I have refused to fight with > >I suspect this will carry on working. :-) Good! > But you and I may be the only ones still monitoring it >OK, thanks, I suspect it may be rather more difficult than I had hoped. > >What I'm aiming for is a Pi/BBB type system that can clone itself >automatically every day or so. That would allow me to have a fairly >quick to implement backup for my Pi (could justas well be a BBB) that >provides DHCP/DNS on my LAN. Mostly I think folks do that with rsync https://man7.org/linux/man-pages/man1/rsync.1.html -- Dennis L Bieber -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/23nvigpjgvll4lpkfm1cfak9uk053okbkp%404ax.com.
[beagleboard] Re: Is it possible to change boot device 'programmatically'?
Dennis Lee Bieber wrote: > > I'm surprised this post even came through. The beagleboard forum > /moved/ to a new web-based-only system (which I have refused to fight with I suspect this will carry on working. :-) Good! > -- I tried but found it cryptic and unusable for someone accustomed to > newsreader clients which fetch all messages in a batch and permit later > responses to be made; I abhor web-based "fetch one message, make a reply, > send, fetch next message") > > The Google Groups forum has been abandoned. > > On Wed, 1 Sep 2021 16:50:11 +0100, in gmane.comp.hardware.beagleboard.user > Chris Green wrote: > > >If one has a BBB which normally boots from eMMC is it possible to > >write a script that will reboot from the microSD card? > > > > On current Beagle systems, it is u-Boot which determines the boot > device dynamically. > > That is: > > By default the u-Boot in the eMMC starts processing > > It then scans for a bootable uSD card > > If a valid uSD card is found, it toggles the boot device to > be the > uSD card, and proceeds to load the configuration from the uSD card; > otherwise it continues to load the configuration from the eMMC > > If there is no u-Boot (and maybe other files) found on the eMMC, the > SoC [hardware] boot sequence is to look for a valid uSD card and load > u-Boot from that card. > > The end state: if a bootable uSD card exists, it automatically becomes > the booted image, skipping the rest of the eMMC (u-Boot comes from the > first version found: eMMC then uSD). > > Prior to this form of u-Boot, one was required to hold down the > boot-select button on the BBB to force uSD card load. But that form of > u-Boot vanished near the end of the Wheezy era (Debian 7). This was also > the days of kernel loaded device tree overlays -- u-Boot loaded overlays > came in during the Jessie (Debian 8) era. The two u-Boots are totally > INCOMPATIBLE with Debian versions of the other style (Wheezy u-Boot does > not load DTOs, but Jessie and later Debian kernels expect to find the DTOs > already loaded). > > I don't know enough about u-Boot and uEnv.txt to know if there is some > way to modify uEnv.txt to /not/ transfer control to the uSD card except > when you want to do you back-up stuff. > OK, thanks, I suspect it may be rather more difficult than I had hoped. What I'm aiming for is a Pi/BBB type system that can clone itself automatically every day or so. That would allow me to have a fairly quick to implement backup for my Pi (could justas well be a BBB) that provides DHCP/DNS on my LAN. -- Chris Green · -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/9jv40i-u7eg1.ln1%40esprimo.zbmc.eu.
[beagleboard] Re: Is it possible to change boot device 'programmatically'?
I'm surprised this post even came through. The beagleboard forum /moved/ to a new web-based-only system (which I have refused to fight with -- I tried but found it cryptic and unusable for someone accustomed to newsreader clients which fetch all messages in a batch and permit later responses to be made; I abhor web-based "fetch one message, make a reply, send, fetch next message") The Google Groups forum has been abandoned. On Wed, 1 Sep 2021 16:50:11 +0100, in gmane.comp.hardware.beagleboard.user Chris Green wrote: >If one has a BBB which normally boots from eMMC is it possible to >write a script that will reboot from the microSD card? > On current Beagle systems, it is u-Boot which determines the boot device dynamically. That is: By default the u-Boot in the eMMC starts processing It then scans for a bootable uSD card If a valid uSD card is found, it toggles the boot device to be the uSD card, and proceeds to load the configuration from the uSD card; otherwise it continues to load the configuration from the eMMC If there is no u-Boot (and maybe other files) found on the eMMC, the SoC [hardware] boot sequence is to look for a valid uSD card and load u-Boot from that card. The end state: if a bootable uSD card exists, it automatically becomes the booted image, skipping the rest of the eMMC (u-Boot comes from the first version found: eMMC then uSD). Prior to this form of u-Boot, one was required to hold down the boot-select button on the BBB to force uSD card load. But that form of u-Boot vanished near the end of the Wheezy era (Debian 7). This was also the days of kernel loaded device tree overlays -- u-Boot loaded overlays came in during the Jessie (Debian 8) era. The two u-Boots are totally INCOMPATIBLE with Debian versions of the other style (Wheezy u-Boot does not load DTOs, but Jessie and later Debian kernels expect to find the DTOs already loaded). I don't know enough about u-Boot and uEnv.txt to know if there is some way to modify uEnv.txt to /not/ transfer control to the uSD card except when you want to do you back-up stuff. -- Dennis L Bieber -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/i2cvigt822989kf4gbfu2ob6a5p62osu6v%404ax.com.
