Re: 'error: invalid signature' when booting Windows 10

[David Collier]

On Thu, Dec 13, 2018 at 10:35 PM Pascal Hambourg <address@hidden>
wrote:

> Le 14/12/2018 à 06:13, David Collier a écrit :
> > when I try booting from the usb stick it indeed shows two boot options,
> > 'Patriot Memory PMAP' and 'UEFI: Patriot  Memory PMAP' but when I try
> > picking the UEFI option it fails with message
> >
> > error: file '/boot' not found
>
> Is this a GRUB error ? Does it fallback to a grub rescue prompt ? If
> yes, what do the 'set' and 'ls' commands display ?
>

ah, it turns out it is. set shows a screenful of variables, in particular

cmdpath=(hd4,msdos2)/EFI/BOOT
config_directory=(hd4)/boot/grub/x86_64-efi
config_file=(hd4)/boot/grub/x86_64-efi/grub.cfg
...
grub_cpu=x86_64
grub_platform=efi
...
prefix=(hd4)/boot/grub
...
root=hd4
 ....

ls shows a bunch of drives, some with partitions, some without.

> however, if I boot from this stick in non UEFI mode I see that it has two
> > partitions, and both of them have /boot directory.
> >
> > Any idea what could be wrong? Some search suggests that it could be due
> to
> > the fact that I copied the .iso image to the stick using dd, is this the
> > case?
>
> What ISO image is it ?
>

The one I downloaded from the Debian Mint page


> dd to /dev/sdX is the proper way to write the image if it is a
> ISO-hybrid image.
>
> Instead of using an ISO image on the stick, you could also create a DOS
> or GPT partition table, an EFI partition (FAT) and a Linux partition
> (ext2 or ext4), mount the EFI partition on /boot/efi and the Linux
> partition on /boot/grub and run
>
> grub-install --removable
> update-grub
>
> Then reboot and select the USB stick for boot in UEFI mode.
>

I'll try this on the weekend.

thank you again,
-dc