Hello! I want to see GRUB2's output on a usb serial line.
I was able to achieve my goal on my laptop by following this <https://www.coreboot.org/GRUB2#On_a_USB_serial_or_USB_debug_adapter> and this <https://unix.stackexchange.com/questions/79838/grub-and-usb-serial-support>, resulting in this list of commands used in grub cli: *insmod nativedisk #to not lose drive information after insmod *hci nativedisk ahci insmod ehci insmod ohci insmod uhci insmod usbserial_ftdi terminal_output --append serial_usb0 terminal_input --append serial_usb0 terminfo -a serial_usb0 dumb* The same procedure did not work on my desktop pc, the problem being that grub loses drives information after doing *insmod ehci*, meaning that an *ls* after that returns no disks, and thus all the next commands fail, nothing can be done anymore and I have to reboot. As you can see above, this problem was fixed on my SATA-based laptop by using *nativedisk ahci*, this command doesn't work on the desktop pc because it uses NVMe (pcie) drives, and the *ahci* module is for SATA drives, not pcie drives. So my question is, how do I keep GRUB from losing drive information when insmoding the various *hci modules? And more importantly, *why* does it happen? Why am I having pcie issues when trying to use a usb port? The GRUB's docs page of nativedisk <https://www.gnu.org/software/grub/manual/grub/grub.html#nativedisk> doesn't list any parameter that can be used, so I don't even know where the guy from the second link got the *nativedisk ahci* idea from. Thanks for your help.
