mount-usb switched to dynamic USB device detection a while back,
so eliminate instances of CONFIG_BOOT_USB_DEV, and derive the
mounted USB device from /etc/mtab in the one place where it's
actually needed (usb-scan). Clean up areas around calls to
mount-usb for clarity/readability.
Addresses issue #673
Test: Build Librem 13v4, boot ISO file on USB
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
To be able to boot a disk image, passed to QEMU with `-hda
/path/qemu.img`, the appropriate modules are needed. Strange, `libata`
is not enough, and the drive is only detected, when the module `ahci` is
loaded.
> ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100
Tested with QEMU emulator version 2.11.1(Debian 1:2.11+dfsg-1ubuntu7)
with the command below,
qemu-system-x86_64 -enable-kvm -M q35 -m 1G -bios \
qemu-coreboot/coreboot.rom -serial stdio -L /dev/shm -hda \
/dev/shm/qemu-debian.img
where `qemu-debian.img` is created with grml-debootstrap.
grml-debootstrap --vmfile --vmsize 3G --target \
/dev/shm/qemu-debian.img -r sid
