Syslinux - Apr 2010 - Bug-report: Memdisk regression for XMGR DOS memory manager

For the boot floppy at http://superkeen.com/peacecorpsfiles/FUZOMA14.IMG
using memdisk from syslinux version 3.72 boots correctly, but for
memdisk versions newer than 3.72 (I tested 3.73, 3.75, 3.85, and 3.86)
all hang at boot with the following message:

Loading boot sector... booting
FreeDOS kernel - SVN (build 2039 OEM:0xfd [compiled Oct 2 2009])
Kernel compatibility 6.22 - BORLANDC
...
XMGR, 11-22-2009 48 XMS handles
Kernel: allocated 48 diskbuffers = 25536 Bytes in HMA

The syslinux.cfg file I am using is as follows:

default linux
label linux
kernel /memdisk
append initrd=/FUZOMA14.IMG

The boot medium I am using is a superfloppy-formatted FAT32 USB drive.

The OS I am running is Ubuntu 9.10 on amd64, though since I'm using the
upstream compiled binary version of syslinux and memdisk I don't think
this should matter.

( forwarded from report at
http://bugs.launchpad.net/unetbootin/+bug/556416 )

On 04/09/2010 10:41 PM, Geza Kovacs wrote:
> For the boot floppy at http://superkeen.com/peacecorpsfiles/FUZOMA14.IMG
> using memdisk from syslinux version 3.72 boots correctly, but for
> memdisk versions newer than 3.72 (I tested 3.73, 3.75, 3.85, and 3.86)
> all hang at boot with the following message:
Could you try the 3.73 prereleases to narrow down the problem, or if you
have the ability to do a "git bisect" that would be even better?

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

Good day Geza,

In regards to your MEMDISK regression claim: I cannot reproduce the
failure with the latest MEMDISK.  To test, I used QEmu 0.9.1 with:

qemu -kernel memdisk -initrd fuzoma14.img -append "pause" -hda foo.hdd

Could you confirm that you experience this trouble on more than one
particular type of hardware?  If not, what type of hardware are you
using?

- Shao Miller

On 04/10/2010 01:57 AM, H. Peter Anvin wrote:
> On 04/09/2010 10:41 PM, Geza Kovacs wrote:
>> For the boot floppy at
http://superkeen.com/peacecorpsfiles/FUZOMA14.IMG
>> using memdisk from syslinux version 3.72 boots correctly, but for
>> memdisk versions newer than 3.72 (I tested 3.73, 3.75, 3.85, and 3.86)
>> all hang at boot with the following message:
> 
> Could you try the 3.73 prereleases to narrow down the problem, or if you
> have the ability to do a "git bisect" that would be even better?
> 
> 	-hpa
> 
Among the 3.73 prereleases, pre2 boots correctly, while pre3 and pre4
have the hanging issue.

On 04/10/2010 02:59 AM, Geza Kovacs wrote:
> On 04/10/2010 01:57 AM, H. Peter Anvin wrote:
>> On 04/09/2010 10:41 PM, Geza Kovacs wrote:
>>> For the boot floppy at
http://superkeen.com/peacecorpsfiles/FUZOMA14.IMG
>>> using memdisk from syslinux version 3.72 boots correctly, but for
>>> memdisk versions newer than 3.72 (I tested 3.73, 3.75, 3.85, and
3.86)
>>> all hang at boot with the following message:
>>
>> Could you try the 3.73 prereleases to narrow down the problem, or if
you
>> have the ability to do a "git bisect" that would be even
better?
>>
>> 	-hpa
>>
> 
> Among the 3.73 prereleases, pre2 boots correctly, while pre3 and pre4
> have the hanging issue.
Additionally, the commit 50b496340e63a7d81c6033b739381af2858d8ac2 works
correctly, so the problematic commit is apparently
02b692d367343df7eed8c1b1a0f435424e8b3a56 (MEMDISK: default to
"safeint"
mode)

Good day again Geza,

If indeed the "safeint" default is where MEMDISK broke for you, you
might try some of the alternative modes available in
syslinux/doc/memdisk.txt, such as:

raw
bigraw
int

on your APPEND line and see if one of them makes a difference.

- Shao Miller

On 04/10/2010 10:42 AM, Miller, Shao wrote:
> If indeed the "safeint" default is where MEMDISK broke for you,
you
> might try some of the alternative modes available in
> syslinux/doc/memdisk.txt, such as:
> 
> raw
> bigraw
> int
> 
> on your APPEND line and see if one of them makes a difference.
> 
Adding any of those 3 options fixes the issue on the 3.86 version.