uefi-riscv64: add cloud kernel target

[igorpecovnik]

Summary

x86 and arm64 UEFI both have a cloud kernel variant; riscv64 didn't. Adds the missing pair so a riscv64 cloud image (qcow2 / vhdx for QEMU + KVM hosts running riscv64 VMs) builds out of the box.

Changes

File	Change
`config/boards/uefi-riscv64.csc`	Append `cloud` to `KERNEL_TARGET`
`config/kernel/linux-uefi-riscv64-cloud.config`	New — lean cloud config seeded from `linux-uefi-arm64-cloud.config` (close arch peer), ARM64 lines stripped, RISCV lines added

Why arm64-cloud as the template

• `x86-cloud`: 398 lines
• `arm64-cloud`: 383 lines
• `riscv64-cloud` (this PR): 382 lines
• (vs `riscv64-current`: 3148 lines — way too fat for a VM kernel)

arm64-cloud is the closer arch peer (no x86-specific microcode, ACPI variants, Intel ME, etc.). Three arm64-only options removed:

• `CONFIG_ARM64_VA_BITS_48`
• `CONFIG_ARM64_PSEUDO_NMI`
• `CONFIG_CRYPTO_AES_ARM64_CE`

Two riscv64-only options added (the same two `linux-uefi-riscv64-current.config` declares):

• `CONFIG_RISCV_SBI_V01=y`
• `CONFIG_SERIAL_EARLYCON_RISCV_SBI=y`

The rest of the cloud config is arch-agnostic — virtio drivers, BPF, IP stack, cgroups, KVM-guest essentials, virtio-gpu / simpledrm for graphics. Same shape as the other two cloud variants.

Existing wiring already covers the rest

The cloud-specific build-framework behavior already lives in `uefi_common.inc`:

```bash
cloud)
declare -g KERNEL_MAJOR_MINOR="6.18"
declare -g LINUXCONFIG="linux-uefi-${LINUXFAMILY}-cloud"
declare -g INSTALL_ARMBIAN_FIRMWARE="no"
declare -g EXTRAWIFI="no"
declare -g UEFI_GRUB_TIMEOUT=0
declare -g QCOW2_RESIZE_AMOUNT="16G"
add_packages_to_image qemu-guest-agent spice-vdagent
```

No changes needed there — LINUXFAMILY=riscv64 + BRANCH=cloud now resolves to a real config.

Test plan

• `./compile.sh build BOARD=uefi-riscv64 BRANCH=cloud RELEASE=trixie BUILD_MINIMAL=yes` produces an image
• qcow2 variant boots in qemu-system-riscv64 with KVM if available, falls back to TCG otherwise
• qemu-guest-agent + spice-vdagent installed inside (`dpkg -l`)
• Kernel modules: `lsmod` shows virtio-net, virtio-blk, virtio-gpu loaded; no SBC drivers

Summary by CodeRabbit

• New Features

  • Added official "cloud" kernel target for UEFI RISC-V64 systems.
  • Default kernel command line updated to enable a framebuffer+serial (dual) console for cloud images.

• Bug Fixes

  • Improved bootloader installation to avoid failures when device-tree blobs are absent, making cloud/VM boots more reliable.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: a1086715-4a50-4de3-9b83-da6adbbffcca

📥 Commits

Reviewing files that changed from the base of the PR and between f102587 and 5f30fc0.

📒 Files selected for processing (1)

• config/sources/families/include/uefi_common.inc

---

📝 Walkthrough

Walkthrough

Adds cloud to the UEFI RISC-V64 board kernel targets, includes an Armbian-generated linux-uefi-riscv64-cloud kernel .config (kernel 6.18), makes GRUB DTB copying conditional, and appends console=tty1 to the UEFI cloud branch kernel cmdline.

Changes

UEFI RISC-V64 Board Configuration

Layer / File(s)	Summary
Kernel target configuration config/boards/uefi-riscv64.csc	KERNEL_TARGET is updated to include cloud alongside current, edge, and legacy.
Add linux-uefi-riscv64-cloud kernel config config/kernel/linux-uefi-riscv64-cloud.config	Adds a complete Armbian-generated kernel .config (kernel 6.18) with core options, networking/netfilter, drivers, filesystems, security/crypto, tracing, and RISC-V SBI/early console settings.
GRUB DTB copy guard in installer extensions/grub-riscv64.sh	pre_umount_final_image__install_grub now checks /boot/dtb for files before creating ${chroot_target}/boot/efi/dtb and copying DTBs; logs and skips copy if none present.
UEFI cloud branch kernel cmdline config/sources/families/include/uefi_common.inc	Appends console=tty1 to GRUB_CMDLINE_LINUX_DEFAULT in the cloud branch and documents the resulting dual-console behavior.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested labels

Patches

Poem

🐰 A tiny hop to mark the day,
Cloud target added on its way,
A kernel long, options in tow,
GRUB skips DTBs when none will show,
Console lines settle, builds aglow.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: adding a 'cloud' kernel target to the uefi-riscv64 board configuration.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch uefi-riscv64-add-cloud-kernel

---

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