Anyone have 4.8-RELEASE running on a real 386 processor (not a 486, 586 etc) ?

I have a 386 that runs 4.7, dmesg as below, both GENERIC & my own kernel.
But it wont boot either 4.8 { generic or my own config} compiled on my
other 4.8 box.  I tried making with & without /etc/make.conf
	CFLAGS =        -m386 -march=i386 -msoft-float -mcpu=i386 -O -pipe
	COPTFLAGS=      -m386 -march=i386 -msoft-float -mcpu=i386 -O -pipe
I tried the /kernel copied from a 4.8 cdrom to hard disk (no cdrom
drive on the box).  I tried 4.8 boot floppies (to prove its not
something wrong in hard disc /boot) They all crash during boot -s.

This 386 box is no bigger than a book, hence I persevere with it,
(though I have modern boxes too :-)
"SX 33" written on chip, though dmesg reports "DX".

I recall 386 support was dropped in 5.0, but I do not see any signs
of dropping 386 in 4.8 /usr/share/mk when I compare with 4.7 /usr/share/mk.
The 4.8 cdrom /[A-Z]* files say i386 is still supported.

I removed the only card in the box (a 3com ISA ethernet jumperless) - still
wouldnt boot, so put ethernet card back in.

I compiled a kernel with ddb,  Results copied by hand as no serial for
remote gdb.

I'm stuck.  Any ideas ?

4.8 ddb:
   Fatal trap 1: priveleged instruction fault while in kernel mode
   instruction pointer = 0x8:0xc02695a0
   stack pointewr      = 0x10:0xc0379fcc
   frame pointer       = 0x10:0xc0379fcc
   code segment	    = base 0x0, limit 0xfffff, type 0x1b
   		    = DPL 0, pres 1, def 32 1, gran 1
   processor eflags    = interrupt enabled, resume, IOPL = 0
   current process     = Idle
   interrupt mask      = net tty bio cam
   kernel: type 1 trap, code=0
   stopped at 0xc02695a0:     invlpg  0(%ecx)
   db> trace
   (null)(c0391000,fd8000) at 0xc02695a0
   (null)(37e000,0,0,0,0) at 0xc0262b8f
   (null)() at 0xc0121aea
   db> ps
   pid   proc     addr   uid  ppid  pgrp   flag  stat wmesg  wchan  cmd
     0 c02f4400 c0377000   0     0     0  000000  0


4.8 dmesg
   FreeBSD 4.7-RELEASE #0: Wed Apr  9 16:08:31 CEST 2003
       jhs @ king:/usr1/src/sys/compile/MINI.small
   Timecounter "i8254"  frequency 1193182 Hz
   CPU: i386DX (386-class CPU)
   real memory  = 16646144 (16256K bytes)
   avail memory = 13115392 (12808K bytes)
   Preloaded elf kernel "kernel" at 0xc0343000.
   md0: Malloc disk
   npx0: <math processor> on motherboard
   npx0: 387 emulator
   isa0: <ISA bus> on motherboard
   orm0: <Option ROM> at iomem 0xc0000-0xc7fff on isa0
   fdc0: <NEC 765 or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0
   fd0: <1440-KB 3.5" drive> on fdc0 drive 0
   ata0 at port 0x1f0-0x1f7,0x3f6 irq 14 on isa0
   atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
   atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
   kbd0 at atkbd0
   vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
   sc0: <System console> at flags 0x100 on isa0
   sc0: VGA <16 virtual consoles, flags=0x300>
   sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
   sio0: type 16450
   ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
   ppc0: Generic chipset (NIBBLE-only) in COMPATIBLE mode
   plip0: <PLIP network interface> on ppbus0
   lpt0: <Printer> on ppbus0
   lpt0: Interrupt-driven port
   ppi0: <Parallel I/O> on ppbus0
   ep0: <3Com 3C509B-Combo EtherLink III (PnP)> at port 0x210-0x21f irq 3 on isa0
   ep0: Ethernet address 00:a0:24:c3:ee:86
   ad0: 4134MB <IBM-DCAA-34330> [8400/16/63] at ata0-master BIOSPIO
   Mounting root from ufs:/dev/ad0s1a
   IP packet filtering initialized, divert disabled, rule-based forwarding enabled,
    default to deny, logging disabled

==============
To: freebsd-hackers @ freebsd.org
cc:	"Erik Trulsson" <ertr1013 @ student.uu.se>,
	"John Baldwin" <jhb @ FreeBSD.org>,
	"Peter Jeremy" <peterjeremy @ optushome.com.au>,
	"Michael Elbel" <mwe @ consol.de>,
	"Gary Jennejohn" <gj @ freebsd.org>
Fcc: sent
Subject: Re: Anyone seen 4.8-RELEASE running on a real 386 (not 486 586 etc) ? 
In-Reply-To: Message from Erik Trulsson <ertr1013 @ student.uu.se> 
   of "Thu, 10 Apr 2003 21:38:10 +0200." <20030410193810.GA52024 @ falcon.midgard.homeip.net> 

Erik Trulsson wrote:
> On Thu, Apr 10, 2003 at 08:43:04PM +0200, Julian Stacey wrote:
> > Anyone seen 4.8-RELEASE running on a real 386 processor (not a 486, 586 etc
> 
> Try the following patch.
> Makes my 386sx/33 work fine at least.
> (Without it I get the same panic as you do.)

This works :-)  I'm now running 4.8, Thanks !

-----------

> From: John Baldwin <jhb @ FreeBSD.org>

> > Try the following patch.
> > Makes my 386sx/33 work fine at least.
> > (Without it I get the same panic as you do.)
> 
> Oh my, I hope that isn't it.  If so it's my fault. :(
> 
> Hmm, can you try this patch instead?
> 
> http://www.FreeBSD.org/~jhb/patches/4x_386.patch

Theses patches Did Not fix the problem. They also did not apply
cleanly to 4.8, perhaps made against current or stable ?
whatever, it was easy to see what you intended, so I produced a 4.8
compliant set, including both Erik's & yours commented out at:

http://www.berklix.com/~jhs/src/bsd/fixes/freebsd/src/gen/sys/i386/i386/i386_cpu.REL=4.8-RELEASE.diff

I'm not sure if Erik's one line patch is good to commit for all
processors (I haven't read the logic, just know i fixes my 386).
If anyone want to send me new patches to test before they commit,
feel free.  Ideally that would be in next day or so, before I return
machine to remote service (where boot failure is inconvenient, but
I could test later too if necessary).

--------------

> From: Peter Jeremy <peterjeremy @ optushome.com.au>
> 
> AFAIK, the only difference is external bus width (SX is 16 bit, DX is
> 32 bit).  It's only 486 where the SX means half the CPU doesn't work.

Thanks, I'd forgotten that.

> >I recall 386 support was dropped in 5.0, but presume not dropped in 4.8,
> 
> It's only dropped in 5.0 GENERIC - you should still be able to compile
> your own kernel with I386_CPU specified (and all other CPU options removed).

I built one, but it hung, but no problem, it probably wanted 5 instead
of 4 type entries in /dev & /boot, maybe later I'll try 5 on that
box, but for now I want it as a 4 service machine so dont want to
change dev & boot, thanks though.

> More useful would be a debug kernel and a crash dump.  You can then
> use gdb on it and find the offending line of source code.

Yes, sorry I missed that.

> >   Fatal trap 1: priveleged instruction fault while in kernel mode
> >   instruction pointer = 0x8:0xc02695a0
> 
> If you can't get a crash dump, do an 'nm -n' on the kernel and find
> the function containing this address.

Not sure what the 0x8: means (I hated segmented 8086 asm from day one :-)

c02693cc T pmap_mincore
c02694a8 T pmap_activate
c026950c T pmap_addr_hint
c0269534 T pmap_pte
c0269570 T pmap_kenter
c02695a8 T pmap_kremove
c02695d8 T procfs_read_regs
c02695f8 T procfs_write_regs
c0269618 T procfs_read_dbregs

> >   stopped at 0xc02695a0:     invlpg  0(%ecx)
> 
> invlpg doesn't exist on i386 - you have to invalidate the entire TLB.
> It looks like someone forgot to protect an invlpg instruction.

OK, Erik & John seem to have a handle on this, thanks.

-
Julian Stacey       Freelance Systems Engineer, Unix & Net Consultant, Munich.
  Ihr Rauchen => mein allergischer Kopfschmerz !   Schnupftabak probieren.