Re: Use SMP kernel for Alpha (udeb) builds

Hi Bob, Michael,

On 12/8/18 21:03, Bob Tracy wrote:
> On Sat, Dec 08, 2018 at 07:41:15PM +0100, Frank Scheiner wrote:
>> On 12/8/18 15:05, Bob Tracy wrote:
>> So can we assume `CONFIG_ALPHA_GENERIC=y` also activates
>> `CONFIG_ALPHA_LEGACY_START_ADDRESS`?
> 
> I wouldn't assume so, particularly for the Gentoo kernel source tree to
> whatever extent it differs from the kernel.org source tree.
> 
> What the dependency is saying is, you can't have the legacy start address
> config option force-enabled unless you're building a generic kernel.

Thanks for the clarification.

> Otherwise, the (alpha) processor-specific config options presumably
> dictate whether the legacy start address is used.  This is, I think,
> why Gentoo includes a generic+lsa kernel and a generic+nolsa kernel in
> their install image.

Not helpful for our problem, but say, does the generic+nolsa kernel also 
boot on your PWS? I'd actually expect it to work.

Because if that lsa is really only needed for older bootloaders (as 
mentioned on [1]), using a nolsa kernel on an older Alpha with a current 
bootloader shouldn't be a problem.

[1]: https://cateee.net/lkddb/web-lkddb/ALPHA_LEGACY_START_ADDRESS.html

But then I don't understand why Gentoo "today" still needs two different 
kernels.

> Just to be clear, Gentoo's generic kernel *does* have SMP configured, and
> *with* the legacy start address enabled should boot just fine on your PWS
> as it does on mine.

Yes, I expect that, too. But if SMP support really has a play in our 
problem, than the Gentoo kernels (being both SMP capable) cannot provide 
"new" information for our problem.

BTW, the patches applied by Gentoo for a slightly newer kernel (4.14.72) 
are available on [2].

[2]: https://dev.gentoo.org/~mpagano/genpatches/patches-4.14-72.html

> The kernel version is 4.14(.65).

I was missing the time yesterday, so tested the Debian generic kernel on 
my ES45 today. it behaves like the DS25, i.e. it seems to hang after 
aboot starts the kernel:

As I'm still missing a "MMJ to whatever" adapter I "copied" this from a 
glass console:
```
[...]
bootstrap code read in
base = 2fc000, image_start = 0, image_bytes = 90b86c(9484396)
initializing HWRPB at 2000
initializing page table at ffff0000
initializing machine state
setting affinity to the primary CPU
jumping to bootstrap code
aboot: Linux/Alpha SRM bootloader version 1.0_pre20040408
aboot: switching to OSF/1 PALcode version 1.92
aboot: loading initrd (4874860 bytes/9522 blocks) at 0xfffffc00ffb46000
aboot: starting kernel network with arguments root=/dev/nfs 
ip=:::::eth0:dhcp console=tty1 net.ifnames=0 biosdevname=0
```

Another thing to note: Pushing (and releasing) the halt button on the 
ES45's OCP has no effect afterwards (I haven't yet checked that on my 
DS25). Doing the same when the Debian SMP kernel has started and the OS 
is running returns me immediately to the SRM prompt. So this mechanism 
seems to be broken by loading the Debian generic kernel.

Cheers,
Frank