Re: [PATCH] util/grub.d/30_os-prober.in: Conditionally show or hide chain and efi menu entries

[Pascal Hambourg]

On 17/01/2024 at 17:48, Vladimir 'phcoder' Serbinenko wrote:
> Le mer. 17 janv. 2024, 18:10, Pascal Hambourg <pascal@plouf.fr.eu.org> a
> écrit :
> > On 17/01/2024 at 04:15, Vladimir 'phcoder' Serbinenko wrote:
> > > > +if [ "\$grub_platform" != "efi" ]; then
> > >
> > > This is not the right check. Only "pc" platform supports chainloadin
> > > boot sector. All other: coreboot, qemu, emu, ieee1275, xen and
> > > non-x86. The only one which might is xen_pvh but this needs to be
> > > checked

From 
<https://wiki.xenproject.org/wiki/Understanding_the_Virtualization_Spectrum#PVH>:

"This is exactly what PVH is. It’s a fully PV kernel mode, running with 
paravirtualized disk and network, paravirtualized interrupts and timers, 
no emulated devices of any kind (and thus no qemu), no BIOS or legacy boot"

If I understand correctly, "no BIOS or legacy boot" implies no boot 
sector chainloading.

> > I expect os-prober to report boot type "chain" only on platforms which
> > support chainloading. Isn't it enough ?
>
> Os-prober has no idea how system is booted. And one of my systems can boot
> as any of coreboot, multiboot, EFI, PC or xen. Then I can run qemu version
> using whole disk. This together means that the same disk can boot in any
> way.

Fine, then assume that os-prober boot type "chain" actually means "BIOS 
boot sector" and show menu entries only if grub_target = pc ?