How to collect debug information while booting kernel on powerpc 32 bit
Hello, I cannot boot a powerbook g4 with kernels more recent than 3.16. Using 5.6 and 5.7 from sid, the system blocks after printing these lines: pmac32_cpufreq: registering PowerMac CPU frequency driver pamc32_cpufreq: Low: 667 MHz, High: 867 Mhz, Boot: 667 MHz I opened a bug report (#963689) but I would like to contribute more information. How may I debug the problem? I tried a lot of kernel parameters without having any additional information on the screen. Would it be helpful to connect a serial cable (where?), use it to connect a console, and get more info? Is there any parameter that may be used for collecting more information when creating the initrd image? Thank you, Giuseppe
Re: How to collect debug information while booting kernel on powerpc 32 bit
On 7/1/20 4:51 PM, Giuseppe Sacco wrote: > How may I debug the problem? I tried a lot of kernel parameters without > having any additional information on the screen. Would it be helpful to > connect a serial cable (where?), use it to connect a console, and get > more info? Is there any parameter that may be used for collecting more > information when creating the initrd image? Try setting up a netconsole [1][2], that usually works just fine. Adrian > [1] https://wiki.ubuntu.com/Kernel/Netconsole > [2] https://www.kernel.org/doc/Documentation/networking/netconsole.txt -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaub...@debian.org `. `' Freie Universitaet Berlin - glaub...@physik.fu-berlin.de `-GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
Re: How to collect debug information while booting kernel on powerpc 32 bit
Hello Adrian, Il giorno mer, 01/07/2020 alle 20.02 +0200, John Paul Adrian Glaubitz ha scritto: > On 7/1/20 4:51 PM, Giuseppe Sacco wrote: > > How may I debug the problem? I tried a lot of kernel parameters without > > having any additional information on the screen. Would it be helpful to > > connect a serial cable (where?), use it to connect a console, and get > > more info? Is there any parameter that may be used for collecting more > > information when creating the initrd image? > > Try setting up a netconsole [1][2], that usually works just fine. Thank you for those links. I was not aware of such console, so I spent some time studying it. Unfortunately, I cannot use it since the kernel stops before listing the Ethernet device. Another option i would like to try, is to test kernel versions in between 3.16 and 5.7, in order to find about when the problem start. I couldn't find a guide for cross compiling the debian kernel package. Do you know if it is possible to cross compile the powerpc kernel on a debian 10 machine with amd64 arch? Thank you, Giuseppe
