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/Arch/aarch64/Platform.cpp

@@ -8,6 +8,7 @@
 #include <Arch/Cpu.hpp>
 #include <Arch/Smp.hpp>
 #include <Arch/aarch64/Gic.hpp>
+#include <Arch/aarch64/Bringup.hpp>
 #include <ACPI/FADT.hpp>
 #include <Terminal/Terminal.hpp>
 #include <CppLib/Stream.hpp>
@@ -57,10 +58,7 @@ namespace Arch {
         KernelLogStream(OK, "PSCI") << "PSCI through " << (g_psci == PsciConduit::Hvc ? "HVC" : "SMC");
     }
 
-    void EarlyInitialize() {
-        // No per-CPU data yet: Smp::TryGetCurrentCpuData must see null.
-        asm volatile("msr tpidr_el1, xzr");
-
+    void InitializeCpuRegisters() {
         // Run on SP_EL1 so exceptions taken from the kernel arrive on the
         // stack it is already using (Vectors.S has no SP_EL0 handlers).
         asm volatile("mov x9, sp\n\tmsr spsel, #1\n\tmov sp, x9" ::: "x9", "memory");
@@ -85,6 +83,13 @@ namespace Arch {
         asm volatile("msr cpacr_el1, %0\n\tisb" :: "r"(cpacr));
     }
 
+    void EarlyInitialize() {
+        // No per-CPU data yet: Smp::TryGetCurrentCpuData must see null.
+        asm volatile("msr tpidr_el1, xzr");
+
+        InitializeCpuRegisters();
+    }
+
     // Installed by EarlyInitialize.
     void InitializeTraps() {
         KernelLogStream(OK, "Arch") << "Installed exception vectors at 0x" << base::hex