core: Improve GPU detection and mapping logic

Refactor GPU detection logic to map DRI nodes to their owning GPUs based on vendor IDs. Update messages for detected Intel and AMD GPUs.

misc/build.func

@@ -4233,27 +4233,31 @@ $PCT_OPTIONS_STRING"
       return 0
     fi
 
-    # Check for Intel GPU - look for Intel vendor ID [8086]
-    if grep -q "\[8086:" <<<"$pci_vga_info"; then
-      msg_custom "🎮" "${BL}" "Detected Intel GPU"
-      if [[ -d /dev/dri ]]; then
-        for d in /dev/dri/renderD* /dev/dri/card*; do
-          [[ -e "$d" ]] && INTEL_DEVICES+=("$d")
-        done
-      fi
+    # Map each DRI render/card node to its owning GPU via the PCI vendor ID
+    # exposed in sysfs (/sys/class/drm/<node>/device/vendor). This is required
+    # on multi-GPU hosts: globbing every /dev/dri node onto the first detected
+    # vendor would pass through *both* GPUs and skip the selection prompt.
+    if [[ -d /dev/dri ]]; then
+      for d in /dev/dri/renderD* /dev/dri/card*; do
+        [[ -e "$d" ]] || continue
+        local node vendor
+        node=$(basename "$d")
+        vendor=$(cat "/sys/class/drm/${node}/device/vendor" 2>/dev/null || true)
+        case "$vendor" in
+        0x8086) INTEL_DEVICES+=("$d") ;;        # Intel
+        0x1002 | 0x1022) AMD_DEVICES+=("$d") ;; # AMD/ATI
+        0x10de) ;;                              # NVIDIA - handled via /dev/nvidia* below
+        *) msg_debug "Unmapped GPU vendor '${vendor:-unknown}' for $d" ;;
+        esac
+      done
     fi
 
-    # Check for AMD GPU - look for AMD vendor IDs [1002] (AMD/ATI) or [1022] (AMD)
-    if grep -qE "\[1002:|\[1022:" <<<"$pci_vga_info"; then
-      msg_custom "🎮" "${RD}" "Detected AMD GPU"
-      if [[ -d /dev/dri ]]; then
-        # Only add if not already claimed by Intel
-        if [[ ${#INTEL_DEVICES[@]} -eq 0 ]]; then
-          for d in /dev/dri/renderD* /dev/dri/card* /dev/kfd; do
-            [[ -e "$d" ]] && AMD_DEVICES+=("$d")
-          done
-        fi
-      fi
+    [[ ${#INTEL_DEVICES[@]} -gt 0 ]] && msg_custom "🎮" "${BL}" "Detected Intel GPU"
+    [[ ${#AMD_DEVICES[@]} -gt 0 ]] && msg_custom "🎮" "${RD}" "Detected AMD GPU"
+
+    # AMD compute (ROCm) additionally needs /dev/kfd alongside the render nodes
+    if [[ ${#AMD_DEVICES[@]} -gt 0 && -e /dev/kfd ]]; then
+      AMD_DEVICES+=("/dev/kfd")
     fi
 
     # Check for NVIDIA GPU - look for NVIDIA vendor ID [10de]