[syslinux] Question of syslinux chainloading

[Lu Wei]

On 2019-4-10 1:20, Ady Ady via Syslinux wrote:
>>> Test #2: if you unplug the USB and reboot the system, can you
>>> successfully boot directly to the HDD's OS?
>>> 
>> Yes. The only HDD, NTFS, WindowsXP native boot loader ntldr.
> 
> 
> Let me rephrase my question. It was/is clear that you used to be able
> to boot Windows when the first boot device was the HDD. Then you used
> the USB as first boot device. My question is, whether now (after you
> have been "playing" with this USB device) you can still repeat the
> former successful boot when using the HDD alone, as it used to be.
> Maybe this is also the intention of your answer, but I would like to
> be sure we are both referring to the same thing / scenario / case.
> So, can you (still)?

Yes. Whether with or without USB device plugged in, BIOS can boot to
Windows on fixed HD . I set boot preference to USB first, so with USB
plugged in, I press F12 to change BIOS boot order. Or I can set boot
preference to fixed HD first, both OK.
> 
> 
> The failure of "localboot 0x80" directive is not very helpful in this
> case, since we don't even know how exactly this BIOS is recognizing
> the local HDD. There is some chance that "localboot 0x81" (not "80")
> might work successfully, but I wouldn't bet on it.
> 
I tried this, it worked! And I tried localboot 0x80 again, it worked
this time! I cannot make sure what has changed since last try. Anyway,
localboot 0x80|0x81, or 0x00, or 0x any digit,  or localboot only
without numbers, will show two line quickly:
Booting from local disk...
Boot error
Then jump to fixed HD's boot.ini menu and boot normally.
> 
> Please try (and please, use the 'append' directive):
> 
> label hd1_1_swap com32 chain.c32 # Boot to first partition of ... #
> There are space characters, before and after the partition number. 
> append hd1 1 swap
> 
> If that fails too, try:
> 
> label hd1_swap com32 chain.c32 # Boot to first partition of ... #
> There is a space character after the disk number. append hd1 swap
> 
Both succeeded smoothly, without any error message.  I tried "hd0 swap",
yet it is same to "hd0", so it is not swapping 0 and 1 as I think.

I also tried not using 'append' directive. It works too. Would you
please explain the difference of one-line directive and using extra
'append' line?

I'll reply with DOS part in another sub-thread.

-- 
Regards,
Lu Wei
IM:	xmpp:luweitest at riotcat.org
PGP:	0xA12FEF7592CCE1EA