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lvgl-benchmark

:::warning [UNTESTED] Compiles, and the upstream benchmark is well known to be stable. Real per-SoM numbers land in the v1.0 HiL sweep. :::

Wraps the upstream lv_demo_benchmark() — LVGL's canonical performance harness. Walks a fixed scene set (gradients, alpha blends, text rendering, image rotation, …) and reports per-scene FPS.

Source: examples/display/lvgl-benchmark/.

Why run it​

Compare the same demo across SoMs to see what the SoC's declared graphics blocks (metadata/socs/alif/ensemble/e*.json) are actually buying you at runtime:

  • E1M-AEN801 (E8) declares gpu2d, dave2d, and dma2d. The §D.lib.loader emits CONFIG_ALP_LVGL_GPU2D=y + CONFIG_ALP_LVGL_DMA2D=y, and LVGL accelerates the blits.
  • E1M-AEN301 (E3) declares dma2d only — no gpu2d. Loader emits CONFIG_ALP_LVGL_DMA2D=y only; blits fall back to CPU. The FPS drop is the visible measure of what GPU2D buys you.

CONFIG_ALP_LVGL_DAVE2D=y is not emitted on the E8 even though the die declares dave2d: the loader binds one backend per capability class, and gpu2d outranks dave2d in the gpu_2d class (see metadata/libraries/lvgl.yaml). CONFIG_ALP_LVGL_SW_BLIT=y stays set as the always-available fallback.

:::note This is LVGL's own acceleration path These CONFIG_ALP_LVGL_* bindings are LVGL's internal draw-unit hookup, which is a different thing from the portable <alp/gpu2d.h> surface — that one's Alif backend needs a proprietary pack and is bench-unverified. Don't read this benchmark as evidence that <alp/gpu2d.h> is accelerated. :::

This is the requires_cap capability-keyed binding system in action — same source, different CONFIG_* flags per SKU automatically.

Display bring-up​

Like the other Zephyr LVGL examples, the app opens the panel via alp_display_open() and binds LVGL with alp_gui_lvgl_attach() before calling lv_demo_benchmark(), with CONFIG_LV_Z_AUTO_INIT=n set in prj.conf. See lvgl-widgets-demo for the full init sequence and Kconfig table.

CONFIG_LV_DEF_REFR_PERIOD=16 targets a 60 fps refresh. On native_sim the run binds Zephyr's dummy display driver (CONFIG_DUMMY_DISPLAY=y, CONFIG_SDL_DISPLAY=n) — there is no SDL2 window.

board.yaml​

libraries:
  - name: lvgl
    cores: [m55_hp]

som:
  sku: E1M-AEN801           # E8 has GPU2D + DAVE2D + DMA2D populated.

preset: e1m-evk

pins:
  - { e1m: E1M_SPI1, macro: EVK_SPI_BUS_ARDUINO, doc: "Arduino UNO header SPI" }

cores:
  a32_cluster:
    os: "off"
  m55_hp:
    app: ./src
    peripherals:
      - spi
      - gpio

chips:
  - st7789

diagnostics:
  log_level: info

See also​

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