Red Bear OS — microkernel OS in Rust, based on Redox

Derivative of Redox OS (https://www.redox-os.org) adding:
- AMD GPU driver (amdgpu) via LinuxKPI compat layer
- ext4 filesystem support (ext4d scheme daemon)
- ACPI fixes for AMD bare metal (x2APIC, DMAR, IVRS, MCFG)
- Custom branding (hostname, os-release, boot identity)

Build system is full upstream Redox with RBOS overlay in local/.
Patches for kernel, base, and relibc are symlinked from local/patches/
and protected from make clean/distclean. Custom recipes live in
local/recipes/ with symlinks into the recipes/ search path.

Build:  make all CONFIG_NAME=redbear-full
Sync:   ./local/scripts/sync-upstream.sh

local/scripts/test-amd-gpu.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+# Test AMD GPU driver on Red Bear OS
+# Run this inside RBOS (or via QEMU serial console)
+set -euo pipefail
+
+echo "=== AMD GPU Driver Test ==="
+echo ""
+
+# Check if scheme:drm exists
+if [ -e "/scheme/drm" ]; then
+    echo "✅ scheme:drm registered"
+else
+    echo "❌ scheme:drm NOT found — redox-drm daemon not running?"
+    exit 1
+fi
+
+# Check card0
+if [ -e "/scheme/drm/card0" ]; then
+    echo "✅ /scheme/drm/card0 exists"
+else
+    echo "❌ /scheme/drm/card0 NOT found — AMD GPU not detected?"
+    exit 1
+fi
+
+# Try to read connector info
+echo ""
+echo "=== Connector Info ==="
+if command -v modetest &>/dev/null; then
+    modetest -M amd 2>&1 | head -50
+else
+    echo "modetest not available — reading raw scheme"
+    # Read from scheme directly
+    cat /scheme/drm/card0 2>&1 | head -20 || true
+fi
+
+echo ""
+echo "=== PCI Devices (GPU) ==="
+ls /scheme/pci/ 2>/dev/null | while read -r entry; do
+    echo "  $entry"
+done
+
+echo ""
+echo "=== Test Complete ==="