GPT/UEFI booting

[Robert Nestor <rnestor%mac.com@localhost>]

I know that setting up a disk with GPT partitions and UEFI booting isn’t supported (yet) in NetBSD.  But it seems close and I’d appreciate some hints. 

Picked up a cheap laptop that only supports UEFI booting on the internal eMMC disk.  Although it has Legacy boot support, that only works on devices attached via USB.  I’ve discovered that NetBSD-current will run on this laptop and I have it running off a USB stick, so now I’m trying to get it running on the internal eMMC disk.  My last problem is getting boot to work. I know I can do this with Grub or rEFInd, but discovered it’s possible under NetBSD if I only knew the magic!

By “possible under NetBSD” what I mean is I copied the NetBSD-7.99.59-amd64-uefi-install.img over to my internal eMMC disk using dd and tried booting and it worked!  The system came up all the way into the installer.  So I went looking for what magic is being done setting up the bootstrap in that image and I’m lost.

This is what I’ve done so far:
#
# Create the GPT segments
#
gpt create -f ld0
gpt add -s 65536 -t efi -l "EFI System" ld0
gpt add -s 525168 -t ffs -l "NetBSD-root" ld0
gpt add -s 256000 -t swap -l "NetBSD-swap" ld0
gpt add -s 1024000 -t ffs -l "NetBSD-var" ld0
gpt add -s 16264934 -t ffs -l "NetBSD-usr" ld0
gpt add -t ffs -l "NetBSD-home”
#
# Initialize the wedges
#
newfs_msdos -F 16 /dev/rdk0
newfs /dev/dk1
newfs /dev/dk3
newfs /dev/dk4
newfs /dev/dk5
#
# Load NetBSD from the 7.99.59 distribution, make the devices, etc, etc
####
#
# Install the loaders
#
gpt biosboot -A -i 1 ld0
mkdir -p /mnt2/EFI/boot
cp /mnt/usr/mdec/*.efi /mnt2/EFI/boot/
cp /mnt/usr/mdec/boot /mnt
installboot /dev/rdk1 /usr/mdec/bootxx_ffsv1

But this last part on installing the loaders doesn’t quite get me there.  Can anyone give me a pointer, clue or information on how this is done on the uefi-install image that does work on my system?  I think if I had that I’d have a working laptop with a native GPT/EFI boot under NetBSD.

BTW, this is a Lenovo N22 11”.  They’re selling new for less than $200, come with a 64Gig eMMC disk, SDHC slot, a USB 3 port, 2 USB 2 ports, camera and wireless but come with Windows 10 Pro loaded.  It’s a 1.6 Ghz 64-bit system which is a bit underpowered for Windows. The latest versions of Ubuntu and Mint Linux install and run much better, but I’d prefer NetBSD.  Great battery life and seems to be pretty solid construction for a small, lightweight laptop.

Thanks,
-bob