Bug 14282

Summary:	Using FreeBSD 3.* ThinkPad 600E doesn't recognize IBM's 64MB DIMMs
Product:	Base System	Reporter:	jarkko.hietaniemi <jarkko.hietaniemi>
Component:	i386	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	Unspecified
Hardware:	Any
OS:	Any

Description jarkko.hietaniemi 1999-10-12 12:00:00 UTC

Using either FreeBSD 3.3-RELEASE or 3.2-RELEASE an IBM ThinkPad 600E
doesn't boot if there are any IBM 64MB DIMMs installed.  32MB DIMMs
work okay.

Symptom: When booting from the 3.3 boot floppies (ThinkPad doesn't
find 'kernel' from the 3.3 CD-ROM), boot proceeds fine (though there's
one warning sign, of which more shortly) until the point

Probing for PnP devices

That's the last thing ever that happens: after that the boot hangs,
in a major way: floppy drive keeps whirring, nothing happens
on the screen, and nothing short of ripping the battery out
resets the nirvana.  No ctrl-c, no ctrl-alt-del, not even
toggling the power switch of the ThinkPad.  As long as there
is power in the battery, the machine is completely dead.
(After the battery removal, it's dead in another way...)

The one oddity I mentioned earlier: the FreeBSD bootloader
only ever reports 64MB, never more than that, even if there
is 96MB (the base r32 + one 64 DIMM), or 128 (base 32 + 32 + 64).

I had two 64MB DIMMs and one 32MB DIMM and I tested all possible
combinations of having a 64MB or a 32MB on either socket, and using
either 64MB.  No difference.  The only combinations that boot are
the ones that have the (std factory-installed base) 32MB, and either
nothing or just the 32MB DIMM.  Install a 64MB DIMM anywhere, boot
fails.

Moreover, I had two identical ThinkPad 600Es to test this.
So it is unlikely to be a ThinkPad/memory socket/64MB DIMM failure.

Moremoreover, I tested this already in FreeBSD 3.2, and hoped
3.3 to work better.

No, I don't know how a 64MB DIMM has anything to do with the
boot freezing at the aforementioned point.  That just happens.
When I take the 64MB DIMM(s) away, boot succeeds just fine.

The BIOS of the ThinkPad always correcly detects the amount
of the memory.  Windows98 booted fine, too.

DIMMs:
20L0241 Non-Parity S0 DIMM Memory Upgrade
64 MB 66MHz 3.3SV SDRAM 4k Refresh
1- 8Mx64 144-pin (Au) Serial-PD low-power S0 DIMM

Fix: 

Do not use the IBM 64MB DIMMs.
How-To-Repeat: Install an IBM 64MB DIMM into either of the two memory extension sockets.

Comment 1 nate 1999-10-12 16:55:08 UTC

> >Number:         14282
> >Category:       i386
> >Synopsis:       Using FreeBSD 3.* ThinkPad 600E doesn't recognize IBM's 64MB DIMMs
> >Confidential:   no
> >Severity:       serious
> >Priority:       medium
> >Responsible:    freebsd-bugs
> >State:          open
> >Quarter:        
> >Keywords:       
> >Date-Required:
> >Class:          sw-bug
> >Submitter-Id:   current-users
> >Arrival-Date:   Tue Oct 12 04:00:00 PDT 1999
> >Closed-Date:
> >Last-Modified:
> >Originator:     Jarkko Hietaniemi
> >Release:        3.3
> >Organization:
> Nokia Research Center
> >Environment:
> FreeBSD hotspur.research.nokia.com 3.3-RELEASE FreeBSD 3.3-RELEASE #0: Thu Sep 16 23:40:35 GMT 1999     jkh@highwing.cdrom.com:/usr/src/sys/compile/GENERIC  i386
> >Description:
> Using either FreeBSD 3.3-RELEASE or 3.2-RELEASE an IBM ThinkPad 600E
> doesn't boot if there are any IBM 64MB DIMMs installed.  32MB DIMMs
> work okay.

Correct, this is a bug in FreeBSD 'memory sizing' code.  However, *once*
you get FreeBSD installed, you can build a custom kernel that states how
much memory is in the system (using the number printed in the upper-left
corner), and it will work fine.

> That's the last thing ever that happens: after that the boot hangs,
> in a major way: floppy drive keeps whirring, nothing happens
> on the screen, and nothing short of ripping the battery out
> resets the nirvana.

FreeBSD has accessed non-existent memory which hangs the hardware.

Rip out any memory you have so you have less than 64M, and then install
FreeBSD on it.  Build a custom kernel with the MAXMEM option set to 1MB
less than what is in the kernel (you can get more, but that's a good
start).  Something like

options		"MAXMEM=(127*1024)"

(Where in reality you have 128.  Change to whatever your box *really*
has, possibly 96MB/95*1024).

After building and installing the custom kernel, halt the box,
re-install the memory, and boot again.

Everything should work fine.

This *might* be fixed in -current, as I believe -current now uses the
VM86 code to determine how much memory a system has, but I'm unsure of
this.

The bootloader will not be correct, since I believe the BIOS is limited
to only report 64M of memory.


Nate

Comment 2 iedowse freebsd_committer

2001-07-10 00:36:28 UTC

State Changed
From-To: open->feedback


Is this still a problem in more recent releases?

Comment 3 iedowse freebsd_committer

2001-07-10 18:23:25 UTC

State Changed
From-To: feedback->closed


Submitter says this can be closed. Thanks!