* No console output when booting linux from uboot @ 2008-06-03 15:17 Qin, Laigui (GE EntSol, Security) 2008-06-04 16:30 ` Detlev Zundel 0 siblings, 1 reply; 7+ messages in thread From: Qin, Laigui (GE EntSol, Security) @ 2008-06-03 15:17 UTC (permalink / raw) To: linuxppc-embedded [-- Attachment #1: Type: text/plain, Size: 490 bytes --] Hi all, I am trying to boot linux kernel (2.6.23) from uboot (1.3.2) for my custom board. The uboot works well, the kernel booting hit the start_kernel(). But there is nothing output from console. With debugger, I saw that the printk() functions were called many times without any console output. Tracing into the source code, I found that the printk() called "con->write" operation... Can anyone guide me to solve this? Mike Qin GE Security GE imagination at work [-- Attachment #2: Type: text/html, Size: 1258 bytes --] ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: No console output when booting linux from uboot 2008-06-03 15:17 No console output when booting linux from uboot Qin, Laigui (GE EntSol, Security) @ 2008-06-04 16:30 ` Detlev Zundel 2008-06-05 1:55 ` Qin, Laigui (GE EntSol, Security) 0 siblings, 1 reply; 7+ messages in thread From: Detlev Zundel @ 2008-06-04 16:30 UTC (permalink / raw) To: linuxppc-embedded Hi Mike, > I am trying to boot linux kernel (2.6.23) from uboot (1.3.2) for my custom > board. The uboot works well, the kernel booting hit the start_kernel(). But > there is nothing output from console. Do you provide a correct "console=..." parameter? > With debugger, I saw that the printk() functions were called many times without > any console output. Tracing into the source code, I found that the printk() > called "con->write" operation... > > Can anyone guide me to solve this? I have a hint concerning an incorrect conjecture from your side. Usually when start_kernel starts, the kernel knows nothing about consoles to output printk messages to, so in the early phases the printk's (like printk(KERN_NOTICE)) only end up in the internal ring buffer. Its only later when the console is associated with a real device that everything gets sent there. So you shouldn't really wonder why early printk's do not output anything, this is a red herring. Debug the code responsible for the hw acting as your console according to the kernel command line. Cheers Detlev -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de ^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: No console output when booting linux from uboot 2008-06-04 16:30 ` Detlev Zundel @ 2008-06-05 1:55 ` Qin, Laigui (GE EntSol, Security) 2008-06-05 14:22 ` Detlev Zundel 0 siblings, 1 reply; 7+ messages in thread From: Qin, Laigui (GE EntSol, Security) @ 2008-06-05 1:55 UTC (permalink / raw) To: Detlev Zundel, linuxppc-embedded Thanks. Now I am confusing with the way uboot passing parameters to linux kernel: in Uboot 1.2.0: Kernel is entered through the following calling theKernel (linux_argc, linux_argv, linux_env, 0); while in Uboot 1.3.0: (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end); The linux kernel I used is designed with Uboot 1.2.0, while I used 1.3.2. Will this be a problem for passing the parameters? Mike Qin -----Original Message----- From: linuxppc-embedded-bounces+laigui.qin=3Dge.com@ozlabs.org [mailto:linuxppc-embedded-bounces+laigui.qin=3Dge.com@ozlabs.org] On Behalf Of Detlev Zundel Sent: Thursday, June 05, 2008 12:31 AM To: linuxppc-embedded@ozlabs.org Subject: Re: No console output when booting linux from uboot Hi Mike, > I am trying to boot linux kernel (2.6.23) from uboot (1.3.2) for my=20 > custom board. The uboot works well, the kernel booting hit the=20 > start_kernel(). But there is nothing output from console. Do you provide a correct "console=3D..." parameter? > With debugger, I saw that the printk() functions were called many=20 > times without any console output. Tracing into the source code, I=20 > found that the printk() called "con->write" operation... > > Can anyone guide me to solve this? I have a hint concerning an incorrect conjecture from your side. Usually when start_kernel starts, the kernel knows nothing about consoles to output printk messages to, so in the early phases the printk's (like printk(KERN_NOTICE)) only end up in the internal ring buffer. Its only later when the console is associated with a real device that everything gets sent there. So you shouldn't really wonder why early printk's do not output anything, this is a red herring. Debug the code responsible for the hw acting as your console according to the kernel command line. Cheers Detlev --=20 DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: No console output when booting linux from uboot 2008-06-05 1:55 ` Qin, Laigui (GE EntSol, Security) @ 2008-06-05 14:22 ` Detlev Zundel 2008-06-06 11:54 ` Qin, Laigui (GE EntSol, Security) 0 siblings, 1 reply; 7+ messages in thread From: Detlev Zundel @ 2008-06-05 14:22 UTC (permalink / raw) To: linuxppc-embedded Hi Mike, > Thanks. Now I am confusing with the way uboot passing parameters to > linux kernel: > > in Uboot 1.2.0: Kernel is entered through the following calling > theKernel (linux_argc, linux_argv, linux_env, 0); > while in Uboot 1.3.0: > (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end); > > The linux kernel I used is designed with Uboot 1.2.0, while I used > 1.3.2. Will this be a problem for passing the parameters? Hm, now you got me confused. I cannot see the first version anywhere in u-boot or its history. Even in 1.2.0 its either (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end); or (*kernel) ((bd_t *)of_flat_tree, (ulong)kernel, 0, 0, 0); The first path is chosen when using the traditional 2 argument bootm command, the logic being that this is a non-fdt aware kernel. The second path is chosen when using the newer three-argument version of bootm with the third argument being the flat device tree (needs CONFIG_OF_FLAT_TREE in U-Boot 1.2.0). So if you have anything differing from this, you have to conclude for yourself what the situation is. When you have mainline U-Boot and Linux, i.e. comparable what I describe, we especially took care that we are backwards compatible. So by using the two- or three parameter version, we effectively select between two kernel call conventions. The situation stays the same in newer U-Boot versions. Cheers Detlev -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de ^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: No console output when booting linux from uboot 2008-06-05 14:22 ` Detlev Zundel @ 2008-06-06 11:54 ` Qin, Laigui (GE EntSol, Security) 2008-06-07 11:08 ` Detlev Zundel 0 siblings, 1 reply; 7+ messages in thread From: Qin, Laigui (GE EntSol, Security) @ 2008-06-06 11:54 UTC (permalink / raw) To: Detlev Zundel; +Cc: linuxppc-embedded Sorry for the confusing. I just figured out my problem is not for the Uboot version... As you suggested, I debuged the hw action related to serial driver today. I add the "console=3DttyS2" in my uboot bootargs and corrected = some part, but still no output yet. Is there other factors will affect the console output, except the serial driver? BestRegards, Mike Qin -----Original Message----- From: linuxppc-embedded-bounces+laigui.qin=3Dge.com@ozlabs.org [mailto:linuxppc-embedded-bounces+laigui.qin=3Dge.com@ozlabs.org] On Behalf Of Detlev Zundel Sent: Thursday, June 05, 2008 10:22 PM To: linuxppc-embedded@ozlabs.org Subject: Re: No console output when booting linux from uboot Hi Mike, > Thanks. Now I am confusing with the way uboot passing parameters to=20 > linux kernel: > > in Uboot 1.2.0: Kernel is entered through the following calling > theKernel (linux_argc, linux_argv, linux_env, 0); while in=20 > Uboot 1.3.0: > (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end); > > The linux kernel I used is designed with Uboot 1.2.0, while I used=20 > 1.3.2. Will this be a problem for passing the parameters? Hm, now you got me confused. I cannot see the first version anywhere in u-boot or its history. Even in 1.2.0 its either (*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end); or (*kernel) ((bd_t *)of_flat_tree, (ulong)kernel, 0, 0, 0); The first path is chosen when using the traditional 2 argument bootm command, the logic being that this is a non-fdt aware kernel. The second path is chosen when using the newer three-argument version of bootm with the third argument being the flat device tree (needs CONFIG_OF_FLAT_TREE in U-Boot 1.2.0). So if you have anything differing from this, you have to conclude for yourself what the situation is. When you have mainline U-Boot and Linux, i.e. comparable what I describe, we especially took care that we are backwards compatible. So by using the two- or three parameter version, we effectively select between two kernel call conventions. The situation stays the same in newer U-Boot versions. Cheers Detlev=20 -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: No console output when booting linux from uboot 2008-06-06 11:54 ` Qin, Laigui (GE EntSol, Security) @ 2008-06-07 11:08 ` Detlev Zundel 2008-06-07 11:52 ` Matvejchikov Ilya 0 siblings, 1 reply; 7+ messages in thread From: Detlev Zundel @ 2008-06-07 11:08 UTC (permalink / raw) To: linuxppc-embedded Hi Mike, > Sorry for the confusing. I just figured out my problem is not for the > Uboot version... > > As you suggested, I debuged the hw action related to serial driver > today. I add the "console=ttyS2" in my uboot bootargs and corrected some > part, but still no output yet. Is there other factors will affect the > console output, except the serial driver? Actually not that I can think of. Depending on your driver, maybe the default baud rate is not correct? Did you try a "console=ttyS2,115200" for example? Cheers Detlev -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: No console output when booting linux from uboot 2008-06-07 11:08 ` Detlev Zundel @ 2008-06-07 11:52 ` Matvejchikov Ilya 0 siblings, 0 replies; 7+ messages in thread From: Matvejchikov Ilya @ 2008-06-07 11:52 UTC (permalink / raw) To: Detlev Zundel; +Cc: linuxppc-embedded May be console=ttyCPM0,115200 helps? 2008/6/7 Detlev Zundel <dzu@denx.de>: > Hi Mike, > >> Sorry for the confusing. I just figured out my problem is not for the >> Uboot version... >> >> As you suggested, I debuged the hw action related to serial driver >> today. I add the "console=ttyS2" in my uboot bootargs and corrected some >> part, but still no output yet. Is there other factors will affect the >> console output, except the serial driver? > > Actually not that I can think of. Depending on your driver, maybe the > default baud rate is not correct? Did you try a "console=ttyS2,115200" > for example? > > Cheers > Detlev > > -- > DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu@denx.de > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2008-06-07 11:52 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2008-06-03 15:17 No console output when booting linux from uboot Qin, Laigui (GE EntSol, Security) 2008-06-04 16:30 ` Detlev Zundel 2008-06-05 1:55 ` Qin, Laigui (GE EntSol, Security) 2008-06-05 14:22 ` Detlev Zundel 2008-06-06 11:54 ` Qin, Laigui (GE EntSol, Security) 2008-06-07 11:08 ` Detlev Zundel 2008-06-07 11:52 ` Matvejchikov Ilya
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