Syslinux - Jun 2019 - New UEFI restrictions?

Previously I've been using a laptop with an "Aptio Setup
Utility...2015"
to "Disable UEFI Boot" and allow a USBstik with partition1 having:
  /boot/isolinux/isolinux.bin , isolinux.cfg , menu.c32...etc.
 to boot 64bit TinyCore.

Now this newer laptop has: "Aptio Setup Utility...2018"
which is completely different from the 2015 version.

I fail to boot linux from any of my various syslinux/grub bootStiks.
Has M$pook finally locked linux out of <WinTel> laptops?
Or have readers here got a solution?

=TIA crg.

I doubt it was a spec change. More likely, some hacky(not conforming to the
spec) thing you got a way with before, is not working anymore. A more technical
answer would require a detailed explanation of exactly how your boot images are
created, and what the final result actually looks like.

On Sun, Jun 2, 2019 at 4:15 AM eas lab via Syslinux
<syslinux at syslinux.org> wrote:
>
> Previously I've been using a laptop with an "Aptio Setup
Utility...2015"
> to "Disable UEFI Boot" and allow a USBstik with partition1
having:
>   /boot/isolinux/isolinux.bin , isolinux.cfg , menu.c32...etc.
>  to boot 64bit TinyCore.
So BIOS mode.  Good to know.
> Now this newer laptop has: "Aptio Setup Utility...2018"
> which is completely different from the 2015 version.
So an underlying firmware upgrade.
> I fail to boot linux from any of my various syslinux/grub bootStiks.
> Has M$pook finally locked linux out of <WinTel> laptops?
> Or have readers here got a solution?
So the same BIOS mode boot sticks.  This could be a symptom of a more
strict or poorer BIOS CSM (compatibility support module) in the new
firmware.  As Don said, details will help.

Pretend it's a new non-booting PC and try the usual tricks.  Try using
a stick smaller than 4GB, single partition with the hybrid ISO, single
partition with FAT32 and SYSLINUX or a real CD.  My best luck with
BIOS USB boot has been a USB CD drive or a 1-4GB USB stick where I end
up wasting some space and I think end up with unaligned cylinders
(rather than an aligned setup of say H/S 128/32).  I'd end up wiping
the partition table, ejecting/inserting the drive then using fdisk on
Linux and just keep the CHS values it choose but it was a version
before the 1 MiB alignment became default.

-- 
-Gene