[syslinux] isohybrid: slint64-14.1.iso: unable to find mac efi image

[Thomas Schmitt]

Hi,

> Alas, I tried to boot off an USB key on a recent MacBook but that failed.

On the first glimpse it resembles what Colin Watson gives as reason
for having an x86-BIOS-only ISO in the answer to
  http://askubuntu.com/questions/37999/what-is-different-about-the-mac-iso-image
But he talks of CD, not USB stick.
And the mentioned bug report talks of an unusable boot menu.


> I saw two boot media on Apple's Boot Manager, both called EFI Boot (??)

You could try to omit one or both of the images efiboot.img
or macboot.img when producing the ISO and accortingly leave out
the option -m resp. -u if running isohybrid.
(isohybrid will possibly not work with -m if no -u is given.
 I did not try, but the code looks like --mac assumes the
 presence of --uefi and its boot image, because of an unconditional
 "buf += 32" between both cases. One might have to pull it into
 the "if (mode & EFI)" case.)

For a test, you could also try an ISO produced by grub-mkrescue.
It uses xorriso with different options than with the usual ISOLINUX
examples: First MBR partition starts at block 1, HFS+ is integrated
in ISO metadata rather than having a small HFS+ image as data file.
If it works, then one could learn from such an ISO.

(Sorry for mentioning the competitor on this list.
 But to my knowledge nobody yet succeeded with SYSLINUX UEFI
 images via El Torito. So in some way GRUB2 seems to be needed
 as companion of ISOLINUX.)


In summary i have to confess that my knowledge ends at the
boot catalog, the partition tables, and some small manipulations
in the boot image for x86-BIOS.
Neither the overall content of the boot images, nor the activities
of the firmware after finding those images, are in my scope.
I'm just lacking the hardware for exotic adventures.


Have a nice day :)

Thomas