Build Fedora aarch64 images for the Lenovo Yoga C630

Assembles a ready-to-write disk image via Gitea Actions. Mainline has carried
sdm850-lenovo-yoga-c630.dts since 5.5 and Fedora ships it in kernel-core, so
unlike aarch64-laptops/build there is no kernel or GRUB to compile — what is
left is producing an image that boots on firmware which hands Linux no device
tree.

The build runs in an aarch64 container under qemu-user and builds filesystems
from directory trees with mke2fs -d and mcopy rather than mounting loop
devices, so it works on runners that will not hand out /dev/loop-control.

A kernel-install hook writes the devicetree line into each BLS entry; without
it the first `dnf update kernel` would produce an unbootable system.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XWRjNJMistCy6ngXH5aJLS

docs/install.md

@@ -0,0 +1,97 @@
+# Installing on the Yoga C630
+
+## Before you start
+
+Leave Windows in place. Lenovo ships firmware updates only through Windows, and
+the per-model Qualcomm blobs Linux needs live in that partition — wiping it
+means losing audio and the sensor hub permanently. Update everything through
+Lenovo Vantage first.
+
+Disable Secure Boot. The image is not signed for it:
+
+- Press **Fn+F2** during startup, go to **Security → Secure Boot → Disabled**, or
+- **Settings → Update & Security → Recovery → Advanced startup → UEFI Firmware Settings**
+
+## Write the image
+
+```sh
+zstd -d fedora-44-minimal-lenovo-yoga-c630-*.img.zst
+sudo dd if=fedora-44-minimal-lenovo-yoga-c630-*.img of=/dev/sdX bs=4M status=progress oflag=direct conv=fsync
+```
+
+Check `/dev/sdX` twice. An 8 GiB stick is enough for `minimal`, 16 GiB for
+`workstation`; the root filesystem expands to fill whatever you use.
+
+## First boot
+
+Insert the stick and power on holding **Fn+F12** for the boot menu, or enter
+setup with **Fn+F2** and put USB ahead of the internal drive.
+
+GRUB should appear with one entry. It has already been told which device tree to
+load — the C630's UEFI does not supply one, which is the whole reason the
+`devicetree` line exists in the boot loader entry.
+
+First boot does two slow things: it relabels the filesystem for SELinux and
+grows the root partition. Several minutes on a USB stick is normal. Log in as
+`fedora` / `fedora` and set a new password when prompted.
+
+## Extract the Qualcomm firmware
+
+Audio, the sensor hub and video decode do not work until you do this:
+
+```sh
+sudo c630-firmware
+sudo reboot
+```
+
+See [firmware.md](firmware.md) if it cannot find the Windows partition.
+
+## Installing to internal storage
+
+Once the USB image is behaving, copy it onto the internal UFS.
+
+Shrink the Windows partition from within Windows (**Disk Management → Shrink
+Volume**) rather than from Linux — Windows is fussy about its own filesystem
+being moved underneath it.
+
+Then, booted from USB, write the image to the free space. The simplest approach
+that keeps Windows intact is to create the partitions by hand and copy the
+filesystems across rather than `dd`-ing the whole image, since `dd` would
+overwrite the existing GPT and the Windows ESP:
+
+1. `sudo gdisk /dev/sda` — add a `/boot` partition (1 GiB, type 8300) and a root
+   partition (type 8300) in the free space. Keep the existing Windows ESP.
+2. `mkfs.ext4 -O ^orphan_file,^metadata_csum_seed /dev/sdaN` for both.
+3. Copy the running system across with `rsync -aHAX --exclude=/dev --exclude=/proc
+   --exclude=/sys --exclude=/run --exclude=/boot`, then `/boot` separately.
+4. Copy `EFI/fedora` from the USB stick's ESP onto the Windows ESP, and edit
+   `EFI/fedora/grub.cfg` so the `--fs-uuid` matches the new `/boot`.
+5. Update `/etc/fstab` and the `root=UUID=` in
+   `/boot/loader/entries/c630-*.conf` to the new UUIDs.
+
+Finally, point the firmware at GRUB from an Administrator command prompt in
+Windows:
+
+```
+bcdedit /set {bootmgr} path \EFI\fedora\grubaa64.efi
+```
+
+Windows resets this on some updates. To get back, boot the USB stick and run it
+again, or use `efibootmgr` from Linux.
+
+## If it does not boot
+
+The kernel command line is the first thing to change. It lives in
+`options` in `/boot/loader/entries/c630-*.conf`, and GRUB lets you edit it for
+one boot by pressing **e**.
+
+| Symptom | Try |
+|---|---|
+| Hangs immediately after GRUB, no kernel output | Wrong or missing device tree — check the `devicetree` line points at a file that exists in `/boot/dtb-*/qcom/` |
+| Boots then freezes partway | Drop `efi=noruntime`, or add `pd_ignore_unused` if it is missing |
+| USB dies during boot | Add `modprobe.blacklist=qcom_q6v5_pas` |
+| Cannot find root filesystem | The initramfs is missing the UFS drivers — see `overlay/etc/dracut.conf.d/10-c630.conf` |
+| 90-second stall early in boot | Add `systemd.tpm2_wait=0` |
+
+Adding `earlycon` and `ignore_loglevel` will tell you a great deal more about
+which of these it is.