PPC405 support in later 2.4.x kernels
From: Trevor Woerner <hidden>
Date: 2003-08-01 03:32:41
The following email is with respect to the code in the bitkeeper repository at ppc.bkbits.net. I *believe* this is the correct place from which to be getting my kernels? I've been working with a PPC405-based device and wanted to keep up-to-date with the 2.4.x series kernels. I interface to the device via a serial cable console. I had been using 2.4.21-pre7 and it was working well for me. Then I decided to update to an official release, namely 2.4.21, and found the 405 support completely missing! Several of the ppc4xx-specific files in arch/ppc/kernel had the bodies of functions replaced with "implement me!". I am curious to know why. I grabbed 2.4.22-pre8 and found the ppc4xx code back, but the strangest thing is now happening: I've lost my user-space. The kernel boots up perfectly fine, all the printk() messages show up fine, but the last thing I get is kernel message about releasing memory, just before the execve() is called from init/main.c where it's looking for the init() to run. After that I get nothing. I've even put printk()'s in the sys_execve and it runs fine. As soon as the kernel is done printing printk()'s I get nothing more on my serial port. I believe I've done all the standard things, i.e. replace /sbin/init with a shell script, replace /sbin/init with a statically-linked "hello world", remove /sbin/init and watch the kernel panic... It's as if the user-space stuff is going someplace other than the serial port. I searched through the archives and found a tip about turning on math emulation, which I did, but it had no apparent effect. I don't think user-space is coming up. If I ping the box I don't get my packets back, which suggests the interface isn't being set (which is something that would occur if user-space were coming up and running okay). I believe the kernel is still running, I turned on debugging in drivers/char/serial.c and sure enough I do continue to get printk()'s to indicate interrupts. I was thinking of hanging a small routine off of the timer interrupt and printk()'ing something every couple of jiffies, just to see if the kernel is still running. I also noticed that the ppc_bd.progress() functions weren't printing their strings like they were supposed to. This was because the option to allow early boot messages had been removed from the build operation. Perhaps someone more familiar with what's going on in the kernel, and which directions it's going in, might know why I'm seeing what I'm getting? Best regards, Trevor ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/