versal: support DDR apertures above 1 TB in the translation table

[dgarske]

Versal designs can place their DDR aperture above the default address map (a customer design puts it at 0x400_0000_0000), but wolfBoot's translation table only mapped the first 1 TB and hal/versal.ld hardcoded the load origin. This adds VERSAL_DDR_HIGH_BASE/VERSAL_DDR_HIGH_SIZE (512 GB aligned, minimum 1 TB, enforced by assembler .error guards) to map an additional Normal-memory window through new L0/L1 entries, VERSAL_NO_DDR_LOW to leave the low window unmapped when nothing remains at 0x0 (with a compile-time error if used without a high window), and makes hal/versal.ld honor WOLFBOOT_ORIGIN from the config; a commented recipe lands in config/examples/versal_vmk180.config and docs in Targets.md. Verified by building both Versal configs at WOLFBOOT_ORIGIN=0x40000800000 with the window at 0x400_0000_0000 + 1 TB and inspecting the generated tables in the ELF (correct L0 indices, 1 GB Normal blocks across the window, low DDR faulting), plus a stock build confirmed unchanged; not boot-tested, since no bench PDI routes a DDR aperture at that address.

[Copilot]

🟡 Changes recommended

The high-DDR recipe is currently overridden, and translation validation and FIT cache-cleaning gaps remain.

Get a fresh assessment by requesting another Copilot review.

Pull request overview

Adds Versal support for DDR apertures above 1 TB with configurable translation mappings and linker origin handling.

Changes:

• Adds optional high-DDR L0/L1 mappings and low-DDR omission support.
• Makes the Versal linker origin configurable.
• Adds configuration guidance and documentation.

File summaries

File	Summary and review comments
src/boot_aarch64_start.S	Adds high-DDR translation entries and validation. nit (3 votes): the size guard accepts windows below the required 1 TB minimum. nit (1 vote): BOOT_EL1 should clean each FIT destination, including the ramdisk, before disabling the MMU.
hal/versal.ld	Uses configured WOLFBOOT_ORIGIN.
hal/versal.h	Adds high-DDR and low-window configuration controls.
docs/Targets.md	Documents high-aperture deployment.
config/examples/versal_vmk180.config	Adds a high-DDR recipe. moderate (2 votes): the unconditional low origin overrides the recipe, preventing it from selecting the high origin.

Review details

Suppressed comments (1)

src/boot_aarch64_start.S:708

• The high-DDR flow is documented for FIT Linux, but the BOOT_EL1 handoff only cleans the fixed WOLFBOOT_LOAD_ADDRESS window before calling el2_flush_and_disable_mmu(). That helper uses dc cisw set/way flushing, which does not guarantee that dirty kernel, DTB, and ramdisk lines in the newly mapped high window reach PoC on the A72/DSU; Linux can then fetch stale contents after MMU teardown. Clean each actual FIT destination by VA (including the ramdisk) before disabling the MMU.

/* 1 GB Normal-memory blocks covering the high DDR window. */
.balign 4096
MMUTableL1_HI:
.set    SECT, VERSAL_DDR_HIGH_BASE
.rept   (VERSAL_DDR_HIGH_SIZE / 0x40000000)

• Files reviewed: 5/5 changed files
• Comments generated: 2
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.