kernel: lots of tweaks and improvements, WIP: ASN, FileMgr support for OpenHeFS.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

1 files changed, 92 insertions, 0 deletions

diff --git a/src/kernel/HALKit/AMD64/HalTimer.cpp b/src/kernel/HALKit/AMD64/HalTimer.cpp
new file mode 100644
index 00000000..275c1ece
--- /dev/null
+++ b/src/kernel/HALKit/AMD64/HalTimer.cpp
@@ -0,0 +1,92 @@
+// Copyright 2024-2025, Amlal El Mahrouss (amlal@nekernel.org)
+// Licensed under the Apache License, Version 2.0 (see LICENSE file)
+// Official repository: https://github.com/nekernel-org/nekernel
+
+#include <ArchKit/ArchKit.h>
+#include <KernelKit/Timer.h>
+#include <modules/ACPI/ACPIFactoryInterface.h>
+
+/// ================================================================================
+/// @note timer slot 0
+/// ================================================================================
+
+#define kHPETSignature ("HPET")
+
+#define kHPETCounterRegValue (0x00)
+#define kHPETConfigRegValue (0x20)
+#define kHPETCompRegValue (0x24)
+#define kHPETInterruptRegValue (0x2C)
+
+/// ================================================================================
+///! BUGS: 0
+///! @file HalTimer.cc
+///! @brief Hardware Timer (HPET)
+/// ================================================================================
+
+namespace Kernel::Detail {
+struct HPET_BLOCK : public Kernel::SDT {
+  Kernel::UInt8  hardware_rev_id;
+  Kernel::UInt8  comparator_count : 5;
+  Kernel::UInt8  counter_size : 1;
+  Kernel::UInt8  reserved : 1;
+  Kernel::UInt8  legacy_replacement : 1;
+  Kernel::UInt16 pci_vendor_id;
+  ACPI_ADDRESS   address;
+  Kernel::UInt8  hpet_number;
+  Kernel::UInt16 minimum_tick;
+  Kernel::UInt8  page_protection;
+} PACKED;
+}  // namespace Kernel::Detail
+
+using namespace Kernel;
+
+HardwareTimer::HardwareTimer(UInt64 ms) : fWaitFor(ms) {
+  auto power = PowerFactoryInterface(kHandoverHeader->f_HardwareTables.f_VendorPtr);
+
+  auto hpet = (Detail::HPET_BLOCK*) power.Find(kHPETSignature).Leak().Leak();
+  MUST_PASS(hpet);
+
+  fDigitalTimer = (UInt8*) hpet->address.Address;
+
+  if (hpet->page_protection) {
+    HAL::mm_map_page((VoidPtr) fDigitalTimer, (VoidPtr) fDigitalTimer,
+                     HAL::kMMFlagsWr | HAL::kMMFlagsPCD | HAL::kMMFlagsPwt);
+  }
+
+  // if not enabled yet.
+  if (!(*((volatile UInt64*) ((UInt8*) fDigitalTimer + kHPETConfigRegValue)) & (1 << 0))) {
+    *((volatile UInt64*) ((UInt8*) fDigitalTimer + kHPETConfigRegValue)) =
+        *((volatile UInt64*) ((UInt8*) fDigitalTimer + kHPETConfigRegValue)) | (1 << 0) |
+        (1 << 3);  // enable timer & one shot conf
+  }
+}
+
+HardwareTimer::~HardwareTimer() {
+  fDigitalTimer = nullptr;
+  fWaitFor      = 0;
+}
+
+/***********************************************************************************/
+/// @brief Wait for the timer to stop spinning.
+/***********************************************************************************/
+
+BOOL HardwareTimer::Wait() {
+  if (fWaitFor < 1) return NO;
+  if (fWaitFor > 1'000'000) return NO;  // max 1000s = 16 minutes
+
+  UInt64 hpet_cap              = *((volatile UInt64*) (fDigitalTimer));
+  UInt64 femtoseconds_per_tick = (hpet_cap >> 32);
+
+  if (femtoseconds_per_tick == 0) return NO;
+
+  volatile UInt64* timer = (volatile UInt64*) (fDigitalTimer + kHPETCounterRegValue);
+
+  UInt64 now = *timer;
+
+  UInt64 fs_wait = fWaitFor * 1'000'000'000'000ULL;
+  UInt64 stop_at = now + (fs_wait / femtoseconds_per_tick);
+
+  while (*timer < (stop_at)) asm volatile("pause");
+
+  return YES;
+}