feat: aarch64 port - Raspberry Pi 4/400 SD boot (SDHCI, ext2 root + first-boot grow), USB hubs, PCI INTx routing, SMP, DMA fences

kernel/src/Pci/Pci.cpp

@@ -690,6 +690,16 @@ namespace Pci {
     void Initialize(Hal::ACPI::CommonSDTHeader* xsdt) {
         KernelLogStream(INFO, "PCI") << "Initializing PCI subsystem";
 
+        // A plain ECAM walk of a quirky config space reads (and can fault
+        // on) host-bridge registers. Its devices are described by ACPI
+        // instead (Drivers/Init.cpp's platform devices).
+        char quirk[32];
+        if (RootBridgeEcamQuirk(quirk, sizeof(quirk))) {
+            KernelLogStream(WARNING, "PCI") << "Root bridge config space is not ECAM (quirk \""
+                << quirk << "\"): not enumerating PCI";
+            return;
+        }
+
         // Try to parse MCFG for ECAM access; fall back to legacy if unavailable
         ParseMcfg(xsdt);