docs(nh3-pve): BIOS-access paths for the IGFX fix — HDMI-only NanoKVM vs mini-DP RTX; esh-pve as known-good reference

servers/nh3-pve/README.md

@@ -98,9 +98,22 @@ not power back on by itself.
   above).
   ⚠ **Do the BIOS fix on that same visit.** AMT's KVM redirection captures only
   the Intel iGPU's framebuffer, so with the iGPU hidden as it is now, AMT KVM would
-  be just as blind as the NanoKVM. Order: while the NanoKVM is still here (on the
-  RTX through an adapter), set Primary Display = IGFX, provision MEBx, confirm AMT
-  KVM shows the console, and only then move the NanoKVM to the gx10.
+  be just as blind as the NanoKVM. Order: set Primary Display = IGFX, provision
+  MEBx, confirm AMT KVM shows the console, and only then move the NanoKVM to the
+  gx10.
+  **Reaching the BIOS** (2026-09-25 facts). The NanoKVM input is HDMI, the RTX has
+  mini-DP only, and the adapters on hand are mini-DP→DP only. The paths:
+  (1) an **active** mini-DP→HDMI adapter to feed the NanoKVM, since a passive one
+  depends on DP++; (2) a DisplayPort monitor plus a USB keyboard at the rack;
+  (3) pull the card, boot on the iGPU, set IGFX explicitly (not Auto), then refit
+  the card. The NIC pins make a card-out boot safe.
+  `systemctl reboot --firmware-setup` works here (`OsIndicationsSupported` bit 0
+  set), so nobody has to catch the Del key at POST.
+  **An OS-side patch is not possible:** the AMI `Setup`/`SaSetup` variables are not
+  runtime-visible here, unlike on the gx10.
+  **Known-good reference: esh-pve.** Same MS-01, same BIOS `AHWSA.1.17`, same RTX
+  2000E, and its `00:02.0` is present with `boot_vga=1`. The target state works on
+  this hardware.
 
 ## Refresh state