[syslinux] Creating Syslinux UEFI usb boot

[Gene Cumm]

On Mon, Apr 18, 2016 at 5:40 AM, Atle Holm via Syslinux
<syslinux at zytor.com> wrote:
> I am looking for guides on how to create syslinux uefi bootable usb.
> A syslinux bootable usb is created already with vesamenu and luascripting.
> Want to set up the same thing to be UEFI compatible.

What are you doing with Lua?  Offering multiple boot selections
including ESXI's installer?  Or customizing the boot parameters for
ESXi's installer?

> In this case I am booting an vmware esxi installer. /EFI/boot on the vmware ISO has the files BOOTX64.EFI and BOOTIA32.EFI that can be used on the usb. But these always go directly to boot.cfg, syslinux.cfg is never read and thus my boot menu is never shown, an I never get to use the lua scripting.

These binaries are not Syslinux.  They identify themselves as
"mboot_em64t.efi".  Syslinux EFI binaries will have "Syslinux" in
plain text in the binary.

Also, mboot.c32 contains closed source enhancements not available in
Syslinux to read the very same file.  If VMware is willing, I'd love
to review and merge these enhancements.

> I guess syslinux has these efi files somewhere, but on Centos7 I have not found them even when I did install the syslinux package.

The EFI binaries were introduced with 6.00.
http://mirror.centos.org/centos/7/os/x86_64/Packages/ seems to
indicate version 4.05.  I don't know where CentOS or RHEL may place
them, if at all, but in the binary/source archive, they're at
efi64/efi/syslinux.efi and efi32/efi/syslinux.efi.

> The general recipe that I have found is the following:
> - A "EFI/boot" folder for EFI boot, installed manually:
> - Copy all *.c32 objects from "/usr/lib/syslinux/efi64/"
> - Copy "syslinux.efi" to "bootx64.efi" in same folder as above
> - Edit "syslinux.cfg" in "EFI/boot"
>
>
> But as stated, can't find syslinux.efi
> Best regards

I'm pretty sure your packages are of a version that's too old.

The steps necessary for a USB boot that can chainload VMware ESXi's
mboot loader may be possible but only with the latest git commits
however I don't know if they'll be of any use.

-- 
-Gene