Replace GRUB with ZFSBootMenu bootloader

This is a major change that replaces the GRUB bootloader with ZFSBootMenu,
providing native ZFS boot environment support.

Key changes:
- EFI partition reduced from 1GB to 512MB (only holds ZFSBootMenu)
- EFI now mounts at /efi instead of /boot
- Kernel and initramfs live on ZFS root (enables snapshot boot with matching kernel)
- Downloads pre-built ZFSBootMenu EFI binary from get.zfsbootmenu.org
- Creates EFI boot entries for all disks in multi-disk configurations
- Syncs ZFSBootMenu to all EFI partitions for redundancy
- Sets org.zfsbootmenu:commandline on zroot/ROOT for kernel cmdline inheritance
- Sets bootfs pool property for default boot environment
- AMD GPU workarounds (pg_mask, cwsr_enable) added to kernel cmdline when AMD detected

Deleted GRUB snapshot tooling (no longer needed):
- custom/grub-zfs-snap
- custom/40_zfs_snapshots
- custom/zz-grub-zfs-snap.hook
- custom/zfs-snap-prune

Updated helper scripts:
- zfssnapshot: removed grub-zfs-snap call, shows ZFSBootMenu tip
- zfsrollback: removed grub-zfs-snap call, notes auto-detection

Tested configurations:
- Single disk installation
- 2-disk mirror (mirror-0)
- 3-disk RAIDZ1 (raidz1-0)
- All boot correctly with ZFSBootMenu

1 files changed, 0 insertions, 224 deletions

diff --git a/inbox/instructions.txt b/inbox/instructions.txt
deleted file mode 100644
index d6b8461..0000000
--- a/inbox/instructions.txt
+++ /dev/null
@@ -1,224 +0,0 @@
-AMD Strix Halo VPE/CWSR Freeze Fix Instructions
-===============================================
-Created: 2026-01-22
-Machine: ratio (Framework Desktop, AMD Ryzen AI Max 300)
-
-PROBLEM SUMMARY
----------------
-Two AMD GPU bugs cause random freezes on Strix Halo:
-
-1. VPE Power Gating Bug
-   - VPE (Video Processing Engine) tries to power gate after 1 second idle
-   - SMU hangs, system freezes
-   - Fix: amdgpu.pg_mask=0 (disables power gating)
-
-2. CWSR Bug (Compute Wavefront Save/Restore)
-   - MES firmware hang under compute loads
-   - Causes GPU reset loops and crashes
-   - Fix: amdgpu.cwsr_enable=0
-
-Current state on ratio:
-- pg_mask = 4294967295 (power gating ENABLED - bad)
-- cwsr_enable = 1 (CWSR ENABLED - bad)
-- Neither workaround is applied
-
-
-PART 1: GRUB CMDLINE FIX (Quick, can do now)
-============================================
-This adds the parameters to the kernel command line via GRUB.
-Can be done on the running system, takes effect on next boot.
-
-Step 1: Edit GRUB defaults
---------------------------
-sudo nano /etc/default/grub
-
-Find the line:
-GRUB_CMDLINE_LINUX_DEFAULT="..."
-
-Add these parameters (keep existing ones):
-GRUB_CMDLINE_LINUX_DEFAULT="... amdgpu.pg_mask=0 amdgpu.cwsr_enable=0"
-
-Example - if current line is:
-GRUB_CMDLINE_LINUX_DEFAULT="loglevel=2 rd.systemd.show_status=auto rd.udev.log_level=2 nvme.noacpi=1 mem_sleep_default=deep nowatchdog random.trust_cpu=off quiet splash"
-
-Change to:
-GRUB_CMDLINE_LINUX_DEFAULT="loglevel=2 rd.systemd.show_status=auto rd.udev.log_level=2 nvme.noacpi=1 mem_sleep_default=deep nowatchdog random.trust_cpu=off quiet splash amdgpu.pg_mask=0 amdgpu.cwsr_enable=0"
-
-Step 2: Regenerate GRUB config
-------------------------------
-sudo grub-mkconfig -o /boot/grub/grub.cfg
-
-Step 3: Reboot and verify
--------------------------
-sudo reboot
-
-After reboot, verify:
-cat /sys/module/amdgpu/parameters/pg_mask
-# Should show: 0
-
-cat /sys/module/amdgpu/parameters/cwsr_enable
-# Should show: 0
-
-cat /proc/cmdline | grep -oE "(pg_mask|cwsr_enable)=[^ ]+"
-# Should show:
-# pg_mask=0
-# cwsr_enable=0
-
-
-PART 2: MODPROBE.D FIX (Permanent, requires live ISO)
-=====================================================
-This embeds the parameters in the initramfs so they're always applied.
-MUST be done from live ISO because mkinitcpio triggers the freeze.
-
-Step 1: Boot archzfs live ISO
------------------------------
-- Boot from USB with archzfs ISO
-- Get to root shell
-
-Step 2: Import and mount ZFS
-----------------------------
-zpool import -f zroot
-zfs mount zroot/ROOT/default
-mount /dev/nvme1n1p1 /mnt/boot    # Note: nvme1n1p1, not nvme0n1p1!
-
-Verify:
-ls /mnt/boot/vmlinuz*
-# Should show kernel images
-
-Step 3: Create modprobe config
-------------------------------
-cat > /mnt/etc/modprobe.d/amdgpu.conf << 'EOF'
-# Workarounds for AMD Strix Halo GPU bugs
-# Created: 2026-01-22
-# Remove when kernel has proper fixes (check linux-lts >= 6.18 with fixes)
-
-# Disable power gating to prevent VPE freeze
-# VPE tries to power gate after 1s idle, causing SMU hang
-options amdgpu pg_mask=0
-
-# Disable Compute Wavefront Save/Restore to prevent MES hang
-# CWSR causes MES firmware 0x80 hang under compute loads
-options amdgpu cwsr_enable=0
-EOF
-
-Step 4: Chroot and rebuild initramfs
-------------------------------------
-# Mount system directories
-mount --rbind /dev /mnt/dev
-mount --rbind /sys /mnt/sys
-mount --rbind /proc /mnt/proc
-mount --rbind /run /mnt/run
-
-# Chroot
-arch-chroot /mnt
-
-# Rebuild initramfs (this is safe from live ISO)
-mkinitcpio -P
-
-# Verify amdgpu.conf is in initramfs
-lsinitcpio /boot/initramfs-linux.img | grep amdgpu
-# Should show: etc/modprobe.d/amdgpu.conf
-
-# Exit chroot
-exit
-
-Step 5: Clean up and reboot
----------------------------
-# Unmount everything
-umount -R /mnt/dev /mnt/sys /mnt/proc /mnt/run
-zfs unmount -a
-zpool export zroot
-
-# Reboot
-reboot
-
-Step 6: Verify after reboot
----------------------------
-cat /sys/module/amdgpu/parameters/pg_mask
-# Should show: 0
-
-cat /sys/module/amdgpu/parameters/cwsr_enable
-# Should show: 0
-
-lsinitcpio /boot/initramfs-linux.img | grep amdgpu.conf
-# Should show: etc/modprobe.d/amdgpu.conf
-
-
-VERIFICATION CHECKLIST
-======================
-After applying fixes, verify:
-
-[ ] pg_mask shows 0 (not 4294967295)
-[ ] cwsr_enable shows 0 (not 1)
-[ ] Parameters visible in /proc/cmdline (if using GRUB method)
-[ ] amdgpu.conf in initramfs (if using modprobe.d method)
-[ ] System stable - no freezes during idle
-[ ] mkinitcpio -P completes without freeze (test after fix applied)
-
-
-IMPORTANT NOTES
-===============
-
-1. Boot partition UUID
-   ratio has mirrored NVMe drives. The boot partition is on nvme1n1p1:
-   - nvme0n1p1: 6A4B-47A4 (NOT the boot partition)
-   - nvme1n1p1: 6A4A-93B1 (THIS is /boot)
-
-2. Kernel is pinned
-   /etc/pacman.conf has: IgnorePkg = linux
-   This prevents upgrading from 6.15.2 until manually unpinned.
-   DO NOT upgrade to 6.18.x - it has worse bugs for Strix Halo.
-
-3. When to remove workarounds
-   Monitor Framework Community and AMD-gfx mailing list for proper fixes.
-   When linux-lts has confirmed VPE and CWSR fixes, can try removing.
-   Test by commenting out lines in amdgpu.conf, rebuild initramfs, test.
-
-4. If system freezes during mkinitcpio
-   This means the fix isn't active yet. Must do from live ISO.
-   The modconf hook reads /etc/modprobe.d/ at build time, but the
-   running kernel still has the old parameters until reboot.
-
-
-TROUBLESHOOTING
-===============
-
-System still freezes after GRUB fix:
-- Check /proc/cmdline - are parameters there?
-- Check /sys/module/amdgpu/parameters/* - are values correct?
-- If cmdline has them but sysfs doesn't, driver may have loaded before
-  parsing. Need modprobe.d method instead.
-
-Can't import zpool from live ISO:
-- Try: zpool import -f zroot
-- If "pool was previously in use": zpool import -f zroot
-- Check hostid: cat /etc/hostid on installed system
-
-mkinitcpio says "Preset not found":
-- Check /etc/mkinitcpio.d/*.preset files exist
-- For linux kernel: linux.preset
-- For linux-lts: linux-lts.preset
-
-After chroot, wrong mountpoints:
-- Reset mountpoints after any chroot work:
-  zfs set mountpoint=/ zroot/ROOT/default
-  zfs set mountpoint=/home zroot/home
-  (etc. for all datasets)
-
-
-REFERENCES
-==========
-
-VPE timeout patch (not merged):
-https://www.mail-archive.com/amd-gfx@lists.freedesktop.org/msg127724.html
-
-Framework Community - critical 6.18 bugs:
-https://community.frame.work/t/attn-critical-bugs-in-amdgpu-driver-included-with-kernel-6-18-x-6-19-x/79221
-
-CWSR workaround:
-https://github.com/ROCm/ROCm/issues/5590
-
-Session documentation:
-- docs/2026-01-22-ratio-boot-fix-session.org
-- docs/2026-01-22-mkinitcpio-config-boot-failure.org
-- assets/2026-01-22-mkinitcpio-freeze-during-rebuild.org