vexpress64 u boot upstream contribution proposals

vexpress64 U-Boot — Upstream Contribution Proposals

Modernization and contribution opportunities for board/armltd/vexpress64 (ARM Ltd Versatile Express / FVP-Base, BaseR, and Juno targets), based on a comparison against current modern BSPs: total_compute, ti/am62x, qemu-arm, sunxi, and rockchip.

Goal: land a series of small-to-medium patches that modernize the board, become an active reviewer/contributor presence, and get visibility with the maintainers (David Feng, Linus Walleij, Peter Hoyes).

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Summary table

#	Proposal	Tier	Risk	Effort	Visibility
1	Add vexpress64.env text environment file	1	Low	Small	High
2	Implement checkboard()	1	Low	Tiny	Medium
3	Add board_late_init()	1	Low	Small	Medium
4	Standard boot (bootstd / bootflow) support	2	Medium	Medium	High
5	ft_board_setup() for runtime DTB fixups	2	Medium	Medium	Medium
6	EFI capsule update + capsule-on-disk	3	High	Large	High
7	SPL board hooks	3	Medium	Large	Low

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Tier 1 — Good first patches (low risk, high visibility)

1. Add a vexpress64.env text environment file

Modern boards (total_compute, am62x, qemu-arm) ship a .env file instead of cramming CONFIG_EXTRA_ENV_SETTINGS into the config header.

• What: Move boot environment out of include/configs/vexpress_aemv8.h into board/armltd/vexpress64/vexpress64.env, and wire CONFIG_ENV_SOURCE_FILE.
• Why it's a good first patch: pure cleanup, no functional change, idiomatic, easy for reviewers to evaluate.
• Pairs with: #3.

2. Implement checkboard()

vexpress64 currently prints nothing board-specific at boot.

• What: A checkboard() that prints the detected model (Base FVP / BaseR FVP / Juno).
• Why: tiny, self-contained, improves boot diagnostics. Classic "first contribution" size.

3. Add board_late_init()

Currently absent.

• What: Even a minimal hook that sets board_name / fdtfile env from the detected target (useful for bootstd).
• Why: conventional, low-risk, pairs naturally with #1.

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Tier 2 — Medium effort, more substantive

4. Standard boot (bootstd / bootflow) support

qemu-arm enables BOOTSTD_FULL and bootflow scanning; vexpress64 still relies on a hand-written bootcmd.

• What: Enable CONFIG_BOOTSTD / BOOTSTD_FULL and provide the right boot_targets.
• Why: aligns the board with U-Boot's current direction — high community relevance.
• Recommendation: propose on the mailing list before coding.

5. ft_board_setup() for runtime DTB fixups

No runtime devicetree modification hook exists.

• What: Add ft_board_setup() (e.g. to fix up memory or reserved regions at boot).
• Why: well-understood pattern, easy for reviewers to evaluate.

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Tier 3 — Larger / needs design discussion

6. EFI capsule update + capsule-on-disk

am62x and qemu-arm implement firmware capsule update; vexpress64 does not.

• What: Define firmware images, GUIDs, and an update DFU backend; add capsule-on-disk support.
• Why: biggest-impact area, sustained visibility — but needs design buy-in. Not a first patch.

7. SPL board hooks

vexpress64 has no SPL path.

• What: Add SPL board hooks.
• Why: only worth it with a real use case; likely out of scope for FVP.

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Not gaps (don't bother)

• doc/board/armltd/vexpress64.rst already exists and is comprehensive — documentation is not a gap.
• Memory map / MMU regions (vexpress64_mem_map[]) are already correct.

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Suggested sequencing

1. #2 (checkboard) — warm-up to learn the maintainer review flow.
2. #1 (.env) + #3 (board_late_init) — small series that establishes you on the board.
3. #4 (bootstd) — propose on the mailing list first; this is the patch that gets you noticed.
4. #6 (capsule update) — longer-term, higher-impact effort.

Maintainers / references

• Maintainers: David Feng, Linus Walleij, Peter Hoyes
• Board: board/armltd/vexpress64/
• Config header: include/configs/vexpress_aemv8.h
• Docs: doc/board/armltd/vexpress64.rst
• Reference BSPs: total_compute, ti/am62x, qemu-arm, sunxi, rockchip