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

[Didier Spaier]

Hi,

On 13/11/2014 19:17, Ady wrote:
 >> 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,
 >o

 > 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.

Thanks Ady, I appreciate your accuracy and stand corrected.

However, in my use cases at least (providing installers able to boot in
in BIOS _and_ UEFI modes) there's no point in providing _hybrid_ images
relying _only_ on Syslinux as they will be usable _only_ for USB booting
anyway, in case of UEFI.

So if I want to "uniformize" the look of the greeting screens I'll have
to provide "USB only" images, not hybrid ones. Or use grub for both BIOS
and USB booting, but that's out of scope.

Best regards,

Didier