To Jie, You are right that when Android boots up, you will see the logo screen, instead of the Linux console output. I guess this is what you mean by the "tty". What Vishnu said is you won't get the kernel messages on the LCD, but you can get it from a host PC to which you have connected the Android device.
When you specify the "console=<serial tty device>" in the kernel command line (BoardConfig.mk), printk will send kernel messages to the tty device -- if it supports the "console" functionality (not all tty devices do; they have to call "register_console" in the driver). By default, just by setting console=<serial tty device> won't directly display the kernel messages, you will need to connect the device to the host PC (depends on the serial device, it could be a serial cable, or USB cable), and then find the serial device on the host PC (e.g., ttyS0 or ttyUSB1), then you can use "cat" to get the messages. For a quick start, I would suggest that you try "console=tty0", and the kernel messages will be dumped to the screen, and of course, if you only need the kernel, but not the framework for debugging, you can comment out "service zygote" in system/core/rootdir/init.rc to prevent the whole system from booting up. Good luck. Thanks, Danke On Jul 14, 2:21 am, Vishnu Pratap Singh <vishu13...@gmail.com> wrote: > set BOARD_KERNEL_CMDLINE to no_console_suspend=1 console=<Serial TTY device> > <Baud rate of serial port> <loglevel=8> > > Regards > > On Wed, Jul 14, 2010 at 2:38 PM, Vishnu Pratap Singh > <vishu13...@gmail.com>wrote: > > > > > > > Dear Jie, > > > Can you make clear, how you are going to boot prompt, are you using jig box > > for getting boot prompt or serial logs ? > > > On Wed, Jul 14, 2010 at 2:28 PM, Jie <cn.fyo...@gmail.com> wrote: > > >> But Tattoo device booted with a TATTOO logo screen and no ttys will > >> appear to check out the dmesg. It seems like a paradox for android > >> devices. > > >> I've changed the CMDLINE for mkbootimg command but no luck. The > >> bootloader on HTC Tattoo hasn't been hacked so far. Any suggestions? > > >> PS, I'll try it on emulators. > > >> Regards, > > >> On Jul 14, 3:54 pm, Vishnu Pratap Singh <vishu13...@gmail.com> wrote: > >> > actually if you want you can change the debug level in boot parameters > >> also, > >> > this should be present in your bootloader code. > > >> > On Wed, Jul 14, 2010 at 1:20 PM, Vishnu Pratap Singh > >> > <vishu13...@gmail.com>wrote: > > >> > > yes, you can try it out. > > >> > > On Wed, Jul 14, 2010 at 12:24 PM, Jie <cn.fyo...@gmail.com> wrote: > > >> > >> Hi, vishnu > > >> > >> Thanks for quick reply. I've executed 'printenv' on my Tattoo device, > >> > >> 'CMDLINE' environment value isn't there. I guess it should be set in > >> > >> BoardConfig.mk file, right? There is an item named > >> > >> 'BOARD_KERNEL_CMDLINE' in this file. Right now, I set it to > >> > >> 'no_console_suspend=1 console=null' as Google did for other devices. > > >> > >> Is this correct? > > >> > >> Regards, > > >> > >> On Jul 14, 12:10 pm, Vishnu Pratap Singh <vishu13...@gmail.com> > >> wrote: > >> > >> > Hi Jie, > > >> > >> > you can use serial port for getting the logs. on serail port go to > >> boot > >> > >> > prompt and there you just change the log level from 4 to 8 like > >> below > >> > >> > execute -> printenv > >> > >> > it will show the environment there you will see following > > >> > >> > CMDLINE=console=ttySAC2,115200 loglevel=4 > > >> > >> > then execute > >> > >> > setenv CMDLINE=console=ttySAC2,115200 loglevel=*8* > >> > >> > saveenv > >> > >> > * > >> > >> > * > >> > >> > reboot your target, you will get all printk logs. > > >> > >> > regards, > >> > >> > vishnu > > >> > >> > On Wed, Jul 14, 2010 at 9:21 AM, Jie <cn.fyo...@gmail.com> wrote: > >> > >> > > Hi, all > > >> > >> > > I've ported the HTC drivers for 2.6.29 to kernel-msm-2.6.32.9 on > >> my > >> > >> > > HTC Tattoo. After a long time debugging, I completed the > >> compilation > >> > >> > > without any errors. I've compared the .config files of both > >> HTC(.29) > >> > >> > > and android(.32.9) carefully, nothing strange was found. However, > >> the > >> > >> > > phone got stuck after the new boot.img flashed and the adbd had > >> not > >> > >> > > started yet, so I couldn't find any useful debug messages from > >> the new > >> > >> > > kernel. My question is how to debug the kernel on my HTC Tattoo > >> > >> > > without adb. Thanks a lot! > > >> > >> > > Regards, > > >> > >> > > -- > >> > >> > > unsubscribe: > >> > >> > > android-kernel+unsubscr...@googlegroups.com<android-kernel%2bunsubscr...@go > >> > >> > > oglegroups.com> > >> <android-kernel%2bunsubscr...@googlegroups.com<android-kernel%252Bunsubscri > >> b...@googlegroups.com> > > >> > >> <android-kernel%2bunsubscr...@googlegroups.com<android-kernel%252Bunsubscri > >> > >> b...@googlegroups.com> > >> <android-kernel%252bunsubscr...@googlegroups.com<android-kernel%25252Bunsub > >> scr...@googlegroups.com> > > >> > >> > > website:http://groups.google.com/group/android-kernel > > >> > >> -- > >> > >> unsubscribe: > >> > >> android-kernel+unsubscr...@googlegroups.com<android-kernel%2bunsubscr...@go > >> > >> oglegroups.com> > >> <android-kernel%2bunsubscr...@googlegroups.com<android-kernel%252Bunsubscri > >> b...@googlegroups.com> > > >> > >> website:http://groups.google.com/group/android-kernel > > >> > > -- > >> > > Vishnu Pratap Singh > > >> > -- > >> > Vishnu Pratap Singh > > >> -- > >> unsubscribe: > >> android-kernel+unsubscr...@googlegroups.com<android-kernel%2bunsubscr...@go > >> oglegroups.com> > >> website:http://groups.google.com/group/android-kernel > > > -- > > Vishnu Pratap Singh > > -- > Vishnu Pratap Singh -- unsubscribe: android-kernel+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-kernel
