aarch64 interrupts

1 files changed, 49 insertions, 0 deletions

diff --git a/kernel/src/arch/aarch64/cpu/timer.cpp b/kernel/src/arch/aarch64/cpu/timer.cpp
new file mode 100644
index 0000000..eae5cf1
--- /dev/null
+++ b/kernel/src/arch/aarch64/cpu/timer.cpp
@@ -0,0 +1,49 @@
+#include <cstdint>
+#include <generic/time.hpp>
+#include <arch/aarch64/cpu/timer.hpp>
+#include <generic/arch.hpp>
+#include <klibc/stdio.hpp>
+
+void aarch64::timer::init() {
+    aarch64::timer::aarch64_timer* aarch64_timer = new aarch64::timer::aarch64_timer;
+    time::setup_timer(aarch64_timer);
+    klibc::printf("AArch64 timer: Set aarch64 timer as default\r\n");
+}
+
+namespace aarch64 {
+    int timer::aarch64_timer::get_priority() {
+        return 999999;
+    }
+
+    std::uint64_t timer::aarch64_timer::current_nano() {
+        std::uint64_t cntpct_el0 = 0;
+        std::uint64_t cntfrq_el0 = 0;
+        asm volatile("mrs %0, CNTPCT_EL0" : "=r"(cntpct_el0));
+        asm volatile("mrs %0, CNTFRQ_EL0" : "=r"(cntfrq_el0));
+        constexpr std::uint64_t NANOSECONDS_PER_SECOND = 1000000000ULL;
+    
+        #ifdef __SIZEOF_INT128__
+        __uint128_t temp = static_cast<__uint128_t>(cntpct_el0) * NANOSECONDS_PER_SECOND;
+        return static_cast<std::uint64_t>(temp / cntfrq_el0);
+        #else
+        std::uint64_t whole_seconds = cntpct_el0 / cntfrq_el0;
+        std::uint64_t remainder_ticks = cntpct_el0 % cntfrq_el0;
+        
+        std::uint64_t nanos_from_whole = whole_seconds * NANOSECONDS_PER_SECOND;
+        std::uint64_t nanos_from_remainder = (remainder_ticks * NANOSECONDS_PER_SECOND) / cntfrq_el0;
+        
+        return nanos_from_whole + nanos_from_remainder;
+        #endif
+    }
+
+    void timer::aarch64_timer::sleep(std::uint64_t us) {
+        std::uint64_t current = this->current_nano();
+        std::uint64_t end_ns = us * 1000;
+        std::uint64_t target = current + end_ns;
+        
+        while(this->current_nano() < target) {
+            arch::pause();
+        }
+    }
+
+};
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