[syslinux] Question about syslinux EFI alpha version

[Klaus Knopper]

Hello,

On Thu, May 09, 2013 at 12:19:18PM +0100, Matt Fleming wrote:
> On 05/08/2013 02:51 PM, Andreas Heinlein wrote:
> > Am 07.05.2013 15:05, schrieb Klaus Knopper:
> >> Could you please send me a signed copy of your syslinux.efi for 63 and 
> >> 32bit? Maybe it's just my compile environment.
> > Hello,
> > 
> > may I also apply for a copy? :-)
> > 
> > I'm one of the authors of the Ubuntu Privacy Remix live system and I am 
> > currently trying to accomplish much the same like Klaus, i.e. keep our 
> > Syslinux-based boot menus and configs while making the whole thing work 
> > on EFI-systems as well.
> 
> The 6.00 preleases include copies of syslinux.efi for both 32-bit and
> 64-bit at efi32/efi/syslinux.efi and efi64/efi/syslinux.efi,
> respectively.

I must have missed these when checking out the git source. Anyways.
Looks like the newer EFI firmware OVMF-X64-r11337-alpha supports the
"MS-Dos" format of syslinux.efi (including the 0-size header bug).

> You shouldn't need to request copies form me explicitly
> unless, like Klaus, you're trying to debug something.

My current findings:

1. syslinux.efi looks for and loads ldlinux.sys in the current directory
(which is in fact ldlinux.c32 and should be changed to something 32- or
64-bit specific so multiplatform boot is supported).

2. My kernel images are not loaded since "format 0x20b not supported".
(same kernel works with grub.efi and elilo.efi)

3. Config files of syslinux version 4 are found and used in
boot/syslinux, however, the boot picture does not display.

My wishlist:

1. Possibility to generate syslinux.efi as a single binary with no
dynamic loading of ldlinux.sys or *.c32 required. This would also make
multiplatform support easier, renaming syslinux.efi/64bit to
bootx64.efi, and syslinux.efi/32bit to bootx32.efi.

2. Support of my EFIstub-enabled bzImage format (maybe xz-compression
type is to blame?)

> > Since I'm not that good at compiling and debugging low-level code (much 
> > less than Klaus', I assume..) I'd be very happy to test a compiled 
> > binary. BTW: Will it be neccessary to use Syslinux 6 on the "classic" 
> > BIOS side as well, or can the configs be shared with Syslinux 5 or even 4?
> 
> Configs are generally backwards compatible.

I can confirm this.

Regards
-Klaus