Re: RaspberryPi Kernel - Fails to boot when sound driver is a built-in

Chris Tapp

Hi Paul,

On 24 Jun 2012, at 16:25, Paul Eggleton wrote:

On Monday 18 June 2012 22:16:44 Chris Tapp wrote:
If I build the RPi kernel (SRCREV 3fc65f9f291fb19cad434968a4a0f66ab749e637)
then the board boots as expected.

However, if a modify the .config (either manually after -c configure, or by
-c menuconfig) so that CONFIG_SND, CONFIG_SND_TIMER, CONFIG_SND_PCM and
CONFIG_BCM2835 are set to 'y' (i.e. changed from modules) then the kernel
no longer boots.

Has anyone else tried to do this? I'm trying to get a kernel that has ALSA
working out-of-the-box.
Well, FWIW I can't even get a kernel with the default configuration built from
meta-raspberrypi to boot - I even tried copying it to a Debian SD-card and it
doesn't boot there either. All I get is a black screen or with the newer
firmware I get the four-colour display which apparently indicates it couldn't
load the kernel.

Any suggestions would be welcome...

1) Are you using the SRCREVs as supplied, or have you updated them?
2) Which version of the bootfiles are you using?

Everything is in such a state of flux at the moment that it does seem to be difficult to be sure what works one day will work if you upgrade anything to use the latest versions. I can get some combinations to work, the most up-to-date being:

1) Use the bootfiles with SRCREV = "9308c7ed387e5422883753f7fb71a75506abd1f8"
2) Build the kernel using SRCREV = "3fc65f9f291fb19cad434968a4a0f66ab749e637"

Later kernels should be 'better', but I've not yet got any to boot. I use the serial port to monitor the boot and this shows nothing. Not seen if the color bars show as I've not looked - will do next time I have a play.

BTW - you need to update the .conf file for the machine to use ttyAMA0 if you want to use the serial port for kernel debug.

There have been a lot of changes to the kernel / bootfiles that mean you must update both to get a working image. Some of these relate to where the image is loaded, some to how the screen is activated (my config.txt entries to set the HDMI video mode stopped working at one point). It seems as if nothing is really fixed at the moment and you need to be prepared to 'do some digging' if you change anything. When I get a moment I want to suggest that a list of matched SRCREVs for 'stable' builds that have been verified can be kept somewhere.

Chris Tapp


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