Using the hints I got here, I realized that /proc/apm
is supposed to be created (for x86) by:
apm_init() @ arch/x86/kernel/apm_32.c
I added some debug printk messages in some places I considered related.
From these I learned the following:
1. In setup_arch(...) @ arch/x86/kernel/setup.c:
apm_info.bios = boot_params.apm_bios_info;
it has the value:
apm_info.bios.version == 0
2. In apm_init() @ arch/x86/kernel/apm_32.c:
if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
printk(KERN_INFO "apm: BIOS not found.\n");
return -ENODEV;
}
It gets here with
apm_info.bios.version == 0
This is why 'dmesg' shows:
apm: BIOS not found
and thus /proc/apm is not created.
3. In query_apm_bios() @ arch/x86/boot/apm.c
I added debug puts messages.
But 'dmesg' showed none of them.
Could it be that some boot-command line parameters are not well passed
to the kernel?
Is the 'initrd' involved in this? I am not familiar with the 'black art' of
constructing 'initrd'. I am using mkinitramfs for this.
The initrd I get does manage to bring up the kernel, the file-systems
and a essentially - a running system.
I still have not tried compiling apm directly into the kernel.
I may try it later, but I believe the problem lies elsewhere.
Thanks for all the tips -- yotam
On Fri, 31 Dec 2010 14:23:35 -0800
Randy Dunlap <rdunlap@xenotime.net> wrote:
