kexec might work if you combine these two grub images: lnxboot.img and core.img, like...

cat lnxboot.img core.img > your-kexec-able.img 

Worth trying that.

Edit: Now that I looked inside the images, lnxboot.image looks more like an "ELF" than lnxboot.img, so try that one too.

kexec might work if you combine these two grub images: lnxboot.img and core.img, like...

cat lnxboot.img core.img > your-kexec-able.img 

Worth trying that.

EDIT:

Now that I looked inside the images, lnxboot.image looks more like an "ELF" than lnxboot.img, so try that one too.

EDIT:

Aparently, the /boot/grub2/i386-pc/xxx.img images are not to the liking of kexec. Then why not try using grub-mkimage to genrate some different formats, and see what works? From the man page, -O, --format=FORMAT supports a whole bunch of other formats. Maybe try the x86_64-xen format.

kexec might work if you combine these two grub images: lnxboot.img and core.img, like...

cat lnxboot.img core.img > your-kexecable.img 

Worth trying that.

kexec might work if you combine these two grub images: lnxboot.img and core.img, like...

cat lnxboot.img core.img > your-kexec-able.img 

Worth trying that.

Edit: Now that I looked inside the images, lnxboot.image looks more like an "ELF" than lnxboot.img, so try that one too.