Round 32: MILESTONE 3 - banner + prompt live on krane panel

RESEARCH.md

@@ -1189,3 +1189,39 @@ override is the intended extension mechanism and is upstreamable.
 PROBE REVIVE MAPTBL LBIO FMT GEO → screen clears → banner (white on
 black) + U-Boot prompt. If anything still fails, the ABORT!/panic
 text now lands on the panel.
+
+## Round 32 — MILESTONE 3 ACHIEVED: banner + prompt live on the panel
+
+Round 31 (`34b9660f…`) works: the user reports the U-Boot banner and
+the prompt rendered white-on-black on the krane panel, via the
+standard video uclass + vidconsole on the depthcharge scanout. The
+full boot chain to a working framebuffer console is:
+
+depthcharge → payload (arm64 Image header + wrapper v3 @0x40 +
+U-Boot @0x1000, runtime _start 0x40001000) → wrapper (revive display,
+3 blinks, 5 s hold) → U-Boot start.S (4K check ✓, PIE fixup, delta
+-0xC000000) → board_init_f → relocation → board_r → console_init_r →
+krane.env stdout=serial,vidconsole → iomux → stdio_probe_device →
+mt8183_scanout probe (revive OVL + backlight, LBIO parse, fallback
+OVL_L0_ADDR=0xFD536000) → video_clear → vidconsole0 → banner.
+
+Key fixes that made it work (final state):
+1. TEXT_BASE=0x4C001000 (8-aligned ⇒ no linker fill ⇒ _start ==
+   __image_copy_start == _TEXT_BASE; PIE delta 4K-aligned).
+2. Payload layout: U-Boot file at image offset 0x1000 ⇒ runtime
+   _start 0x40001000 (both 4K constraints).
+3. ENV_IS_NOWHERE + krane.env: stdout=serial,vidconsole (the video
+   device only probes via the iomux lazy path).
+4. get_page_table_size() board override (0x40000) — dynamic
+   mmu_map_region calls (fb + coreboot table) exhausted the default
+   budget ⇒ panic (reset without PANIC_HANG, hang with it).
+
+Still WIP/temporary in the u-boot tree (to revert before upstreaming):
+- all diag band/text instrumentation (mt8183_scanout.c krane_*,
+  video-uclass.c, board_f.c, main.c, interrupts_64.c hook),
+- CONFIG_PANIC_HANG=y, CONFIG_BOARD_LATE_INIT=y,
+- CONFIG_WATCHDOG_AUTOSTART=n (decide: re-enable for production).
+
+Next: milestone 4 — distro_bootcmd booting pmOS from USB (sda), then
+cleanup/upstreaming pass (single-purpose commits, MAINTAINERS,
+checkpatch, revert diagnostics).