[syslinux] Is efiboot.img required?

[piranna at gmail.com]

>> The most annoying thing (to me) is that it doesn't boot at all on
>> Legacy OS mode (MBR), while it should... :-/
>
> No, it shouldn't. If you are initially booting in (U)EFI mode (into
> rEFInd, or some EFI shell or any other EFI boot loader or EFI boot
> manager), then generally speaking you are expected to boot in EFI mode.
> But some (U)EFI firmware _might_ be able to "automagically" boot some
> external media (e.g. USB flash drive) in CSM mode without having to set
> it in the firmware.
>
> To be clear, "recognizing" the USB device in the boot list is not the
> same as being able to boot from it. In general terms, you need to set
> your firmware in CSM mode so to be able to boot in such mode.

Hum, that could be the reason, that rEFInd detect the USB device and
boot methods and show them in the boot list, but later it can't be
able to boot them. Theorically it should be able to "automagically"
change to CSM mode (it's an Apple MacBook, there are no firmware
configurations, or at least not explicit ones), this reminds me that I
didn't test it to boot using the native MacBook boot selector (rEFInd
is usually more powerful, but maybe the problem is here...).


> But that's not the only reason your procedure is failing. The method
> you described in your prior email (copying some files and renaming
> them) is not enough so to make your USB device bootable by SYSLINUX. I
> don't even know where you read such instructions (and please don't
> interpret this as an invitation to point to some guide that has
> incorrect instructions; let's not propagate inadequate information).
>
> In your prior email you have not mentioned executing the 'syslinux'
> (or, alternatively, the 'extlinux') installer command, which is
> required to install SYSLINUX (on your MBR-partitioned with one FAT
> volume USB device) for BIOS systems.

You are right, forget about that. Maybe I got wrong by the fact that
in my initial tests I have scripted the installer and later
syslinux.efi didn't need an installer... Sorry about that.


> And this is only about BIOS booting, before even considering the
> UEFI-related issues.
>
> I would suggest reading:
>  http://www.syslinux.org/wiki/index.php/Install

I'll do it again to see if I've missed something.


-- 
"Si quieres viajar alrededor del mundo y ser invitado a hablar en un
monton de sitios diferentes, simplemente escribe un sistema operativo
Unix."
– Linus Tordvals, creador del sistema operativo Linux