[syslinux] Boot fails in a VMware player VM - syslinux 6.03

[Ady]

> 
> Hi,
> 
> On 11/11/2014 02:55, Ady wrote:
>  > Again, dd'ing your isohybrid image onto your (virtual or real) drive
>  > will fail to boot in EFI mode. Your "syslinux.efi-based"
>  > "/isolinux/efiboot.img" will not be capable of booting. This is one
>  > of the steps that corresponds to grub2, not to whichever other EFI
>  > bootloader you use (e.g. syslinux.efi).
> 
> So, it's not possible (yet?) to provide an hybrid ISO image able to
> boot in UEFI and BIOS modes using Syslinux.
> 
 
That's an inaccurate interpretation. You _can_ build an isohybrid 
image with Syslinux 6.03 for both, BIOS and UEFI firmware. Such 
image:

A_ can be burned to optical media, which then can be used to boot 
BIOS systems; and,

B_ can be dd'ed to a (USB) (flash) drive, which then can be used to 
boot BIOS systems; and,

C_ can be dd'ed to a (USB) (flash) drive, which then can be used to 
boot UEFI systems; and,

D_ can be dd'ed to a (USB) (flash) drive, which then can be used to 
boot either/both BIOS systems or UEFI systems.

E_ can be expanded (I mean, its content) onto a (USB) (flash) drive 
with GPT and a FAT ESP (and legacy "MBR"), which then can be used to 
boot either/both BIOS systems or UEFI systems.

The possibility to perform #B/#C/#D/#E (in addition to #A) depends on 
the content of the isohybrid image and the parameters used by mkisofs 
(or equivalent). One hint:

 -eltorito-alt-boot -no-emul-boot -eltorito-platform 0xEF \
 -eltorito-boot EFI/BOOT/BOOTX64.EFI

(not "-eltorito-boot isolinux/efiboot.img", which is not used by 
Syslinux).

where BOOTX64.EFI comes from (a.k.a. "is a simple copy of"):
 syslinux-6.03/efi64/efi/syslinux.efi.

I am not going to repeat now all additional requirements (such as 
ldlinux.{c32,e64} and that the target system in this example would be 
either a BIOS or a UEFI x86_64 one, among other requirements).

In other words, I was only referring to the limitation of Syslinux in 
UEFI mode about being able to boot *optical media*. Expressing this 
(current) limitation as "[not] able to boot in UEFI and BIOS modes 
using Syslinux" is inaccurate.

Regards,
Ady.