Well, I was to say that I took a quick look to GNU Mach code, and that it seems to just ignore the Multiboot2 information data structure, but it is probably normal, as it use Multiboot "1" Magic: line 18 of http://git.savannah.gnu.org/cgit/hurd/gnumach.git/tree/i386/i386at/boothdr.S #define MULTIBOOT_MAGIC 0x1BADB002
https://en.wikipedia.org/wiki/Multiboot_specification says: "Within the OS image file, the header must be in the first 8192 (2¹³) bytes for Multiboot and 32768 (2¹⁵) bytes for Multiboot2. The loader searches for a magic number to find the header, which is 0x1BADB002 for Multiboot and 0xE85250D6 for Multiboot2." Still, later on that page: "Before jumping to the OS entry point, the boot loader must provide a boot information structure to tell the OS how it left the system; for Multiboot, this is a struct, and for Multiboot2, every field (group) has a type tag and a size. " Maybe I did not search enough, but I did not found that struct in the code yet. So GNU Mach code probably need some refreshment toward using Multiboot2... and save the information data structure somewhere. Or I missed something?