* [U-Boot] break command. @ 2013-02-14 20:19 Sean Omalley 2013-02-15 12:38 ` Albert ARIBAUD 0 siblings, 1 reply; 6+ messages in thread From: Sean Omalley @ 2013-02-14 20:19 UTC (permalink / raw) To: u-boot Is there anyway to break back into u-boot after trying to boot from linux (arm)? Similar to Open Firmwares stop-a, ctrl-break? I didn't see anything in the documentation nor poking around online. I am really hoping I missed something, or there is support that just needs to be compiled in. :) Even if it resets the cpu, or sends a signal to the jtag_reset would be fine. When the machine locks up, I don't want to have to push a button or unplug it since most of the time, I am not in the same vicinity as the machine. Leaving a serial console attached and remoting into another machine is easier and cheaper, then other alternatives. I could send a signal from a gpio to the jtag_reset (or short it), but the machine I would -want- to use doesn't have a gpio, and I don't want to spend money for multiple jtags when it seems more logical to do it through the serial console.? Thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
* [U-Boot] break command. 2013-02-14 20:19 [U-Boot] break command Sean Omalley @ 2013-02-15 12:38 ` Albert ARIBAUD 2013-02-15 19:00 ` Harvey Chapman 0 siblings, 1 reply; 6+ messages in thread From: Albert ARIBAUD @ 2013-02-15 12:38 UTC (permalink / raw) To: u-boot Hi Sean, (can you please set your mailer to wrap lines at about 70?75 characters? Thanks in advance!) On Thu, 14 Feb 2013 12:19:11 -0800 (PST), Sean Omalley <omalley_s@rocketmail.com> wrote: > Is there anyway to break back into u-boot after trying to boot from linux (arm)? Similar to Open Firmwares stop-a, ctrl-break? I didn't see anything in the documentation nor poking around online. I am really hoping I missed something, or there is support that just needs to be compiled in. :) > > Even if it resets the cpu, or sends a signal to the jtag_reset would be fine. When the machine locks up, I don't want to have to push a button or unplug it since most of the time, I am not in the same vicinity as the machine. Leaving a serial console attached and remoting into another machine is easier and cheaper, then other alternatives. I could send a signal from a gpio to the jtag_reset (or short it), but the machine I would -want- to use doesn't have a gpio, and I don't want to spend money for multiple jtags when it seems more logical to do it through the serial console.? As soon as U-Boot gives control to the payload (Linux or whatever) there is no possible assumption that U-Boot remains intact in RAM, so your only chance is indeed some hardware reset... But then the question is not related to U-Boot any more. > Thanks! No problem. Amicalement, -- Albert. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [U-Boot] break command. 2013-02-15 12:38 ` Albert ARIBAUD @ 2013-02-15 19:00 ` Harvey Chapman 2013-02-15 19:03 ` Peter Barada ` (2 more replies) 0 siblings, 3 replies; 6+ messages in thread From: Harvey Chapman @ 2013-02-15 19:00 UTC (permalink / raw) To: u-boot On Feb 15, 2013, at 7:38 AM, Albert ARIBAUD <albert.u.boot@aribaud.net> wrote: > On Thu, 14 Feb 2013 12:19:11 -0800 > (PST), Sean Omalley <omalley_s@rocketmail.com> wrote: > >> Is there anyway to break back into u-boot after trying to boot from linux (arm)? Similar to Open Firmwares stop-a, ctrl-break? I didn't see anything in the documentation nor poking around online. I am really hoping I missed something, or there is support that just needs to be compiled in. :) >> > As soon as U-Boot gives control to the payload (Linux or whatever) > there is no possible assumption that U-Boot remains intact in RAM, so > your only chance is indeed some hardware reset... But then the question > is not related to U-Boot any more. On that note, does anyone know of a device that would do this? Perhaps a combination device like this: - USB interface to a pc - serial port for device - relay controllable A/C power plug (U.S.) - controllable gpio (for wiring to a power button, reset switch, etc) ^ permalink raw reply [flat|nested] 6+ messages in thread
* [U-Boot] break command. 2013-02-15 19:00 ` Harvey Chapman @ 2013-02-15 19:03 ` Peter Barada 2013-02-15 19:28 ` Ira W. Snyder 2013-02-17 20:49 ` Wolfgang Denk 2 siblings, 0 replies; 6+ messages in thread From: Peter Barada @ 2013-02-15 19:03 UTC (permalink / raw) To: u-boot On 02/15/2013 02:00 PM, Harvey Chapman wrote: > On Feb 15, 2013, at 7:38 AM, Albert ARIBAUD <albert.u.boot@aribaud.net> wrote: >> On Thu, 14 Feb 2013 12:19:11 -0800 >> (PST), Sean Omalley <omalley_s@rocketmail.com> wrote: >> >>> Is there anyway to break back into u-boot after trying to boot from linux (arm)? Similar to Open Firmwares stop-a, ctrl-break? I didn't see anything in the documentation nor poking around online. I am really hoping I missed something, or there is support that just needs to be compiled in. :) >>> >> As soon as U-Boot gives control to the payload (Linux or whatever) >> there is no possible assumption that U-Boot remains intact in RAM, so >> your only chance is indeed some hardware reset... But then the question >> is not related to U-Boot any more. > On that note, does anyone know of a device that would do this? Perhaps a combination device like this: > > - USB interface to a pc > - serial port for device > - relay controllable A/C power plug (U.S.) > - controllable gpio (for wiring to a power button, reset switch, etc) > > If your board/processor has it, a watchdog can be used to force a reset if it expires... -- Peter Barada peter.barada at logicpd.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* [U-Boot] break command. 2013-02-15 19:00 ` Harvey Chapman 2013-02-15 19:03 ` Peter Barada @ 2013-02-15 19:28 ` Ira W. Snyder 2013-02-17 20:49 ` Wolfgang Denk 2 siblings, 0 replies; 6+ messages in thread From: Ira W. Snyder @ 2013-02-15 19:28 UTC (permalink / raw) To: u-boot On Fri, Feb 15, 2013 at 02:00:10PM -0500, Harvey Chapman wrote: > On Feb 15, 2013, at 7:38 AM, Albert ARIBAUD <albert.u.boot@aribaud.net> wrote: > > On Thu, 14 Feb 2013 12:19:11 -0800 > > (PST), Sean Omalley <omalley_s@rocketmail.com> wrote: > > > >> Is there anyway to break back into u-boot after trying to boot from linux (arm)? Similar to Open Firmwares stop-a, ctrl-break? I didn't see anything in the documentation nor poking around online. I am really hoping I missed something, or there is support that just needs to be compiled in. :) > >> > > As soon as U-Boot gives control to the payload (Linux or whatever) > > there is no possible assumption that U-Boot remains intact in RAM, so > > your only chance is indeed some hardware reset... But then the question > > is not related to U-Boot any more. > > On that note, does anyone know of a device that would do this? Perhaps a combination device like this: > > - USB interface to a pc > - serial port for device > - relay controllable A/C power plug (U.S.) > - controllable gpio (for wiring to a power button, reset switch, etc) > I have a BayTech network-attached powerstrip that does something similar. It has switchable AC outlets and network-accessible serial ports, but it doesn't have controllable GPIOs or a USB interface. Ira ^ permalink raw reply [flat|nested] 6+ messages in thread
* [U-Boot] break command. 2013-02-15 19:00 ` Harvey Chapman 2013-02-15 19:03 ` Peter Barada 2013-02-15 19:28 ` Ira W. Snyder @ 2013-02-17 20:49 ` Wolfgang Denk 2 siblings, 0 replies; 6+ messages in thread From: Wolfgang Denk @ 2013-02-17 20:49 UTC (permalink / raw) To: u-boot Dear Harvey Chapman, In message <2586B402-FB69-465C-82A4-62A065C74234@3gfp.com> you wrote: > > > As soon as U-Boot gives control to the payload (Linux or whatever) > > there is no possible assumption that U-Boot remains intact in RAM, so > > your only chance is indeed some hardware reset... But then the question > > is not related to U-Boot any more. > > On that note, does anyone know of a device that would do this? Perhaps a combination device like this: > > - USB interface to a pc > - serial port for device > - relay controllable A/C power plug (U.S.) > - controllable gpio (for wiring to a power button, reset switch, etc) The standard approach is to use a hardware watchdog that will reset the board if it is not triggered in time. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de A good marriage would be between a blind wife and deaf husband. -- Michel de Montaigne ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-02-17 20:49 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-02-14 20:19 [U-Boot] break command Sean Omalley 2013-02-15 12:38 ` Albert ARIBAUD 2013-02-15 19:00 ` Harvey Chapman 2013-02-15 19:03 ` Peter Barada 2013-02-15 19:28 ` Ira W. Snyder 2013-02-17 20:49 ` Wolfgang Denk
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