head -r339076's boot loader fails to boot threadripper 1950X system (BTX halted); an earlier version works [ -r336532 broke it ]

[Mark Millard]

[I found what change lead to the 1950X boot crashing
with BTX halted.]

On 2018-Oct-20, at 12:44 PM, Mark Millard <marklmi at yahoo.com> wrote:

> [Adding some vintage information for a loader
> that allowed a native boot.]
> 
> On 2018-Oct-20, at 4:00 AM, Mark Millard <marklmi at yahoo.com> wrote:
> 
>> I attempted to jump from head -r334014 to -r339076
>> on a threadripper 1950X board and the native
>> FreeBSD boot failed very early. (Hyper-V use of
>> the same media did not have this issue.)
>> 
>> But copying over an older /boot/loader from another
>> storage device with a FreeBSD head version that has
>> not been updated yet got past the problem being
>> reported here. (For other reasons, the kernel has
>> been moved back to -r338804 --and with that,
>> and the older /boot/loader, the 1950X native-boots
>> FreeBSD all the way just fine.)
> 
> I found one /boot/loader.old that was dated
> in the update'd file system as 2018-May 20,
> instead of 2018-Apr-03 from the older file
> system. May 20 would apparently mean a little
> below -r334014 . It native-booted okay, as did
> the April one.
> 
> [I do not know how to inspect a /boot/loader*
> to find out what -r?????? it is from.]
> 
> Unfortunately, I had done more than one -r339076
> install from -r334014 before rebooting and
> no -r334014 loaders were still present:
> the other *.old files from a few minutes before
> the ones I had the boot problem with.
> 
> I might be able to extract loaders from various:
> 
> https://artifact.ci.freebsd.org/snapshot/head/r*/amd64/amd64/base.txz
> 
> materials and try substituting them in order to
> narrow the range for works -> fails. If I can,
> this likely would take a fair amount of time in
> my context.
> 
> Other notes:
> 
> It turns out that only Hyper-V based use needed
> a -r334804 kernel: Native booting with the older
> loaders and newer kernels works fine.
> 
> Windows 10 Pro 64bit also has no problems
> booting and operating the machine.
> 
> The native-boot problem does seem to be freeBSD
> loader-vintage specific.
> 
>> For the BTX failure the display ends up with
>> (hand transcribed, ". . ." for an omission):
>> 
>> BTX loader 1.00 BTX version is 1.02
>> Console: internal video/keyboard
>> BIOS drive C: is disk0
>> . . .
>> BIOS drive P: is disk13
>> -
>> int=00000000  err=00000000  efl=00010246  eip=000096fd
>> eax=74d48000  ebx=74d4e5e0  ecx=00000011  edx=00000000
>> esi=74d4e380  edi=74d4e5b0  ebp=00091da0  esp=00091d60
>> cs=002b  ds=0033  es=0033    fs=0033  gs=0033  ss=0033
>> cs:eip=66 f7 77 04 0f b7 c0 89-44 24 0c 89 5c 24 04 8b
>>      45 08 89 04 24 83 64 24-10 00 c7 44 24 08 01 00
>> ss:esp=00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00
>>      00 00 00 00 00 00 00 00-f0 1d 89 00 00 00 00 00
>> BTX halted
> 
> I've no clue what of that output might be loader vintage
> specific. It might not be of use without knowing the
> exact build of the loader.
> 
>> The board is a GIGABYTE X399 AORUS Gaming 7 (rev 1.0).
>> It has 96 GiBytes of ECC RAM, just 6 DIMMs installed.
> 
> For reference for the board's BIOS:
> 
> Version: F11e
> Dated: 2018-Sep-17
> Description: Update AGESA 1.1.0.1a

Using:

https://artifact.ci.freebsd.org/snapshot/head/r*/amd64/amd64/base.txz

materials I found that:

-r336492: worked (loader vs. zfsloader: not linked)
(no more amd64 builds until . . .)
-r336538: failed (loader vs. zfsloader: linked)

(Later ones that I tried also failed.)

Looks like this broke for booting the 1950X 
system in question when the following was
checked in:

Author: imp
Date: Fri Jul 20 05:17:37 2018
New Revision: 336532
URL: 
https://svnweb.freebsd.org/changeset/base/336532


Log:
  Collapse zfsloader functionality back down into loader.
. . .


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)