[syslinux] memdisk operations FAIL to boot with Syslinux-4.02

[Gene Cumm]

On Mon, Aug 30, 2010 at 04:13, Gert Hulselmans <gerth at zytor.com> wrote:
> Prof S W Damle wrote:
>> Hello all
>>

>> Following is my syslinux.cfg:

>> LABEL cmdcons
>> MENU LABEL ^2.cmdcons  =>Windows Recovery Console
>> COM32 chain.c32  fs cmldr=cmldr
>>   APPEND hd0 1 cmldr=cmldr

Again, do not put anything after your kernel image file name as it
will be ignored and only confuse you.

LABEL cmdcons
  MENU LABEL ^2.cmdcons  =>Windows Recovery Console
  COM32 chain.c32
  APPEND hd0 1 cmldr=cmldr


>> LABEL grub4dos
>> MENU LABEL ^3.grub4dos
>> COM32 chain.c32  fs grldr=/grldr/grldr
>>   APPEND file=/grldr/grldr
>> # grub.exe & menu.lst on the device loads GUI
>> # takes @ 1Min to load and then boots
>> #verified boots grub4dos

Same here.

>> LABEL nu2-2
>> MENU LABEL ^2. INSERT\partimage -->Tool to get LinuxPartition_UsbDrv Img
>>
>>  kernel /DiskImages/memdisk
>>   append initrd=/DiskImages/BtInsUSB.img
>>
>> LABEL nu2-4
>> MENU LABEL ^4. Partition Magic8  -->Universal partition manager
>>  kernel /DiskImages/memdisk
>>   append initrd=/DiskImages/Pm8.img
>>
>> LABEL nu2-5
>> MENU LABEL ^5. Plpbt.
>> KERNEL /ISOimages/memdisk
>> INITRD /ISOimages/Plpbt.iso
>> APPEND iso
>>
>> Thanks in advance
>>
>> Prof S W Damle
>>
>
> Which exact error message do you get when booting a MEMDISK entry?

Also, which entries?  It was nice to see the comments of which ones
did work inlined into your configuration as it made that part very
clear.  Do you get different errors with different entries?  What's
the size of the images you're trying to load?  If you're seeing a
message from Syslinux while it's attempting to load the image of "Out
of memory: can't allocate memory for ", you have one of two
situations.

1) The image is just too big for the machine you're using.  For
instance, you can't load an image of 300 MiB+ on a machine with only
256 MiB of RAM (I wouldn't even try an image over 128 MiB on a machine
with 256 MiB unless it's DOS or you _really_ know _exactly_ what
you're doing and how much RAM you need).

2) Your machine has a memory hole that's getting in the way.
http://syslinux.zytor.com/wiki/index.php/Meminfo.c32 can show you how
to see the memory hole.

To resolve #2, try something like the following:

LABEL nu2-5
  MENU LABEL ^5. Plpbt.
  KERNEL linux.c32
  INITRD /ISOimages/Plpbt.iso
  APPEND /ISOimages/memdisk iso

Assuming all file names and paths are correct (including having
linux.c32 in the default folder beside chain.c32).  If this resolves
the issue, please let us know.

-- 
-Gene