*!*!*!$$!! Ken Thompson Boot Loader Interface

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Thu, 24 May 2001 00:22:01



Something is wrong. It goes beep.

Argh!

Is there some deep reason it couldn't at least print an error number I
could look up?

Is there any way I can work out what the hell is hapening?

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Thu, 24 May 2001 02:31:52




Quote:

> Something is wrong. It goes beep.

> Argh!

> Is there some deep reason it couldn't at least print an error number I
> could look up?

> Is there any way I can work out what the hell is hapening?

is this a bios beep? (loose video card, memory stick maybe...) or has the
system gone through the post and beeps when you get to the os booting part?
(scsi adapter? trying to boot from floppy, but no disk in drive?) at what
point does it beep? and is it more than one beep... as in a series that
might sound like morse code? inquiring minds want to know ! :)

Jim

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Thu, 24 May 2001 23:22:25


ja> is this a bios beep? (loose video card, memory stick maybe...) or has the
ja> system gone through the post and beeps when you get to the os
ja> booting part?

The latter. The F1, F2 prompt of the fbsd boot manager. if it's eaven
mildly confused it beeps once and does nothing else.

(I actually worked around it by randomly changing how I was
partitioning the disk, so I not longer have the problem, but this is
clearly not a reasonable way to have to work).

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Fri, 25 May 2001 00:32:01





> ja> is this a bios beep? (loose video card, memory stick maybe...) or has the
> ja> system gone through the post and beeps when you get to the os
> ja> booting part?

> The latter. The F1, F2 prompt of the fbsd boot manager. if it's eaven
> mildly confused it beeps once and does nothing else.

> (I actually worked around it by randomly changing how I was
> partitioning the disk, so I not longer have the problem, but this is
> clearly not a reasonable way to have to work).

hmmm... my guess would be if moving your partitions fixes or at least
alleviates the problem then thats where i would look. when you installed did
you do the "dangerously dedicated" ( i'm guessing not since you're
dual-booting... asking anyway just in case) or as a partition?

 is your other os partition ntfs? I dual boot linux and win2k pro and found
that if i used ntfs on the win2k side sometimes strange things (not entirely
different from what you're having) would happen, not consistent though. when
i installed win2k with fat32 everything went a lot smoother for some reason.

good luck, i'm interested in how you get it going if you do.

Jim

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Fri, 25 May 2001 01:21:59


ja> hmmm... my guess would be if moving your partitions fixes or at least
ja> alleviates the problem then thats where i would look.

Yeah, but there are a semi-infinite number of partition patterns I
could try, I'd like a hint as to what went wrong.

ja> when you installed did you do the "dangerously dedicated" ( i'm
ja> guessing not since you're dual-booting... asking anyway just in
ja> case) or as a partition?

As a normal partition. My first setup was

        Small DOS partition
        Small FBSD partition (for /)
        Big FBSD partition.

The split in the BSD area is because the machine I ws going to put the
disk in (not the one I had it in to install/test) is geriatric and
_may_ have problems with big partitions. I never got as far as moving
the didk because the instalation machine went.

Beep.

I then redid it with no DOS partition, and it booted fine.

maybe it objected to the initial empty DOS partition? Maybe it doesn't
like Tuesdays?

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Fri, 25 May 2001 01:42:30





> ja> hmmm... my guess would be if moving your partitions fixes or at least
> ja> alleviates the problem then thats where i would look.

> Yeah, but there are a semi-infinite number of partition patterns I
> could try, I'd like a hint as to what went wrong.

> ja> when you installed did you do the "dangerously dedicated" ( i'm
> ja> guessing not since you're dual-booting... asking anyway just in
> ja> case) or as a partition?

> As a normal partition. My first setup was

> Small DOS partition
> Small FBSD partition (for /)
> Big FBSD partition.

> The split in the BSD area is because the machine I ws going to put the
> disk in (not the one I had it in to install/test) is geriatric and
> _may_ have problems with big partitions. I never got as far as moving
> the didk because the instalation machine went.

> Beep.

> I then redid it with no DOS partition, and it booted fine.

> maybe it objected to the initial empty DOS partition? Maybe it doesn't
> like Tuesdays?

ok... got a couple ideas now. thinking along the "geriatric" lines here.
some older bios have a prob booting os's after the 1024th? i think cylinder
( 540 Mb mark). try this... first partition free bsd root second partition
dos third free bsd /usr.

another way would be the bsd / then /usr then dos. my experiences so far are
that dos doesn't really care where on the disk it is, of course i may have
been lucky so far ;)

btw how are you doing swap in bsd?

Jim

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Fri, 25 May 2001 01:47:43



on 5/23/01 10:42 AM:




>> ja> hmmm... my guess would be if moving your partitions fixes or at least
>> ja> alleviates the problem then thats where i would look.

>> Yeah, but there are a semi-infinite number of partition patterns I
>> could try, I'd like a hint as to what went wrong.

>> ja> when you installed did you do the "dangerously dedicated" ( i'm
>> ja> guessing not since you're dual-booting... asking anyway just in
>> ja> case) or as a partition?

>> As a normal partition. My first setup was

>> Small DOS partition
>> Small FBSD partition (for /)
>> Big FBSD partition.

>> The split in the BSD area is because the machine I ws going to put the
>> disk in (not the one I had it in to install/test) is geriatric and
>> _may_ have problems with big partitions. I never got as far as moving
>> the didk because the instalation machine went.

>> Beep.

>> I then redid it with no DOS partition, and it booted fine.

>> maybe it objected to the initial empty DOS partition? Maybe it doesn't
>> like Tuesdays?

> ok... got a couple ideas now. thinking along the "geriatric" lines here.
> some older bios have a prob booting os's after the 1024th? i think cylinder
> ( 540 Mb mark). try this... first partition free bsd root second partition
> dos third free bsd /usr.

> another way would be the bsd / then /usr then dos. my experiences so far are
> that dos doesn't really care where on the disk it is, of course i may have
> been lucky so far ;)

> btw how are you doing swap in bsd?

> Jim

oh yea... the dos partition... fat 16 or fat 32? fat 16 has the 2Gb
linitation (total partition size, not necessarily location afaik)
 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Fri, 25 May 2001 02:00:58



>> Small DOS partition
>> Small FBSD partition (for /)
>> Big FBSD partition.

ja> ok... got a couple ideas now. thinking along the "geriatric" lines here.
ja> some older bios have a prob booting os's after the 1024th?

Ah, but both the small partitions were _small_. (~ 250MB).

Besides which the machine I was doing this on usually has a disk in it
which has a 1 GB DOS partition before the FBSD one, so it clearly
doens't have that small a limit.

ja> btw how are you doing swap in bsd?

50MB swap partition in side the big FBSD slice. The target machine has
a massive 8MB of RAM, so it's not going to be doing much that will
require masses of swap space (it's to be a firewall).

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Fri, 25 May 2001 02:11:58


ja> oh yea... the dos partition... fat 16 or fat 32? fat 16 has the 2Gb
ja> linitation (total partition size, not necessarily location afaik)

Neither (created by the FBSD installer but no FS on it at that point).

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Fri, 25 May 2001 02:30:52





>>> Small DOS partition
>>> Small FBSD partition (for /)
>>> Big FBSD partition.

> ja> ok... got a couple ideas now. thinking along the "geriatric" lines here.
> ja> some older bios have a prob booting os's after the 1024th?

> Ah, but both the small partitions were _small_. (~ 250MB).

hmmm... scratching head here...
Quote:

> Besides which the machine I was doing this on usually has a disk in it
> which has a 1 GB DOS partition before the FBSD one, so it clearly

            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Quote:> doens't have that small a limit.

actually, what needs to be is the bootloader part needs to be below the
1024th cylinder... not necessarily the entire partition. so if your dos
partition was 1Gb then your bsd boot partition was past cylinder 1024 (540
Mb area) which "could" be a problem... not always though.

i need to clarify something also to see if i'm understanding correctly.
   > Besides which the machine I was doing this on usually has a disk in it
   > which has a 1 GB DOS partition before the FBSD one, so it clearly
was this setup working correctly before?

Quote:

> ja> btw how are you doing swap in bsd?

> 50MB swap partition in side the big FBSD slice. The target machine has
> a massive 8MB of RAM, so it's not going to be doing much that will
> require masses of swap space (it's to be a firewall).

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Fri, 25 May 2001 03:01:01



>> Besides which the machine I was doing this on usually has a disk in it
>> which has a 1 GB DOS partition before the FBSD one, so it clearly

ja> was this setup working correctly before?

Yep. And is again now. I just swapped the disks because the geriatric
machine is incapable of installing anything (no bootable removable
media).

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Jim Ankru » Fri, 25 May 2001 03:18:01





>>> Besides which the machine I was doing this on usually has a disk in it
>>> which has a 1 GB DOS partition before the FBSD one, so it clearly

> ja> was this setup working correctly before?

> Yep. And is again now. I just swapped the disks because the geriatric
> machine is incapable of installing anything (no bootable removable
> media).                                      ^^^^^^^^^^^^^^^^^^^^^^

  ^^^^^^

like floppies and all that? are you installing this on one machine and then
taking the drive out and trying to boot it in another (geriatric)? if so is
the drive staying in the same location (ie master drive on primary ide
controller on both machines)?

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Fri, 25 May 2001 18:22:15


ja> are you installing this on one machine and then
ja> taking the drive out and trying to boot it in another (geriatric)?

Eventually, but at the point of the error I was just trying to boot it
in the first machine to check the instalation.

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*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Gregory Bon » Sat, 02 Jun 2001 15:29:18



> Is there some deep reason it couldn't at least print an error number I
> could look up?

Because it has to fit in 512 bytes.  (OK 1024 bytes in newer
versions).

(Which is the same reason ed has the Ken Thompson Interface as well!)

 
 
 

*!*!*!$$!! Ken Thompson Boot Loader Interface

Post by Richard Cale » Sat, 02 Jun 2001 17:22:09



>> Is there some deep reason it couldn't at least print an error number I
>> could look up?

gb> Because it has to fit in 512 bytes.  (OK 1024 bytes in newer
gb> versions).

Shortern the prompt text and use the space to ass error number.

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1. getting around Ken Thompson's compiler Trojan

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Hash: SHA1

I was discussing Thompson's famous compiler/login trojan recently and
suggested the following procedure for getting around such attacks.  
Can anyone poke any holes in this?

Let's assume that your copy of gcc has a Thompson-like trojan in it,
and that the source code for gcc is clean (uncorrupted).  When
recompiling the clean source with the dirty (trojan carrying) binary,
you produce a dirty binary.

First, write a program to obfuscate the source code of any other program
by randomizing the variable and function names, as well as the names
of the source code files.

Use the corrupted gcc to build the obfuscated gcc.  The "am I compiling
the compiler?" code in the corrupted gcc won't detect that it is
compiling the compiler and will produce an uncorrupted binary of the
compiler.

Then use the new clean compiler (with the obfuscated symbol table)
to build the clean gcc source, and you will have an uncorrupted,
unobfuscated binary of the compiler which, when fed the clean gcc
source, reproduces itself exactly.

Now, of course, if you knew exactly how I was obfuscating a program,
you might be able to come up with a way to detect when you were
compiling a compiler that worked on obfuscated source. If I knew
your detection algorithm, though,  I could change my obfuscation
algorithm to defeat you.  My sense is that obfuscation is easier
than detection, although I don't know how you would prove such
a thing.

I think the relevant point here is that it is much easier to
write an obfuscating program than a compiler, and certainly much
easier than scrutinizing the assembly code of a compiler.

Chris Marshall

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2. Possibility of using ISDN modem

3. Ken Thompson on Linux

4. When is latest InfoMagic Developers kit due out?

5. boot loader not showing up; installed boot loader record on /dev/hda2

6. 3.9.17 Mesa info

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8. Linux Busmouse HOWTO (part 1/1)

9. Dual boot Debian and XP "boot failure" using XP boot loader

10. Dual booting Windoze 95 and Linux with Quantum Dynamic Boot Loader Installed

11. Using NT's boot loader to boot linux?

12. Booting Win2000 with FreeBSD's boot loader

13. Dual boot: NT Boot Loader and Solaris 8