[syslinux] Question of syslinux chainloading

Lu Wei luweitest at gmail.com
Wed Apr 10 22:29:02 PDT 2019

On 2019-4-10 1:20, Ady Ady via Syslinux wrote:
>>>> #This item fails
>>>> label dos
>>>> menu label MS-^DOS 7.1
>>>> com32 chain.c32 msdos7=io.sys
>> IO.SYS and COMMAND.COM are copied from a Windows98 system on another
>> computer, which is MSDOS7.1; and BOOTSECT.W98 is from Bootpart tool (I
>> compared it with the one from my Windows98 system, and I think they are
>> basically the same except label name, so I use this one), but I think if
>> io.sys is loaded, boot sector should be of no use. I have tried "boot
>> BOOTSECT.W98" and "bss BOOTSECT.W98" without success, so I'd like to
>> jump over it and get to IO.SYS directly.
> Would you please try using the equivalent files for FreeDOS in the USB? You can 
> see the options for chain.c32 in the Syslinux wiki. There are at least 2 wiki 
> pages relevant for chain.c32, so I would suggest taking a look at both of them.
FreeDOS equivalent file of io.sys is kernel.sys, (both use command.com
as CLI shell), and can successfully boot by:
com32 chain.c32 freedos=kernel.sys

> BTW, which exact version of SYSLINUX are you using? Is your chain.c32 from the 
> same exact package / version? FYI, different versions should not be mixed, and 
> the options that chain.c32 actually supports depend on the exact version (with 
> some backward incompatibilities too).
I downloaded syslinux-6.03.zip from official site,  and extracted all
files in \bios to H:\syslinux (sub-directory structure not retained to
reduce path command in syslinux.cfg), except later I found memdisk do
not honor path command and moved it to root. So they must be same version.

Lu Wei
IM:	xmpp:luweitest at riotcat.org

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