Pridana verze v0.1

2026-07-12 05:44:42 +02:00
commit 1266a65b82
40 changed files with 6126 additions and 0 deletions
@@ -0,0 +1,83 @@
+/*
+ * AsterOS Kernel
+ * Autor: Pavel Kalaš
+ * Rok: 2026
+ *
+ */
+
+/*
+ * Tento soubor implementuje ovladac PIT casovace.
+ * Nastavuje frekvenci hardwaroveho casovace, drzi globalni citac tiku
+ * a poskytuje blokujici uspani jadra na zadany pocet milisekund.
+ */
+
+#include "timer.h"
+
+static volatile unsigned long g_ticks = 0;
+
+static inline unsigned long long read_tsc(void) {
+    unsigned int lo;
+    unsigned int hi;
+    __asm__ volatile ("rdtsc" : "=a"(lo), "=d"(hi));
+    return ((unsigned long long)hi << 32) | (unsigned long long)lo;
+}
+
+static int interrupts_enabled(void) {
+    unsigned long long rflags;
+    __asm__ volatile ("pushfq; popq %0" : "=r"(rflags));
+    return (rflags & (1ULL << 9)) != 0;
+}
+
+static void busy_delay_ms(unsigned long ms) {
+    unsigned long long start = read_tsc();
+    unsigned long long wait_cycles = (unsigned long long)ms * 1000000ULL;
+    unsigned long long end = start + wait_cycles;
+
+    while (read_tsc() < end) {
+        __asm__ volatile ("pause");
+    }
+}
+
+static inline void outb(unsigned short port, unsigned char value) {
+    __asm__ volatile ("outb %0, %1" : : "a"(value), "Nd"(port));
+}
+
+void timer_init(unsigned int hz) {
+    unsigned int divisor;
+
+    if (hz == 0) {
+        hz = 100;
+    }
+
+    divisor = 1193180U / hz;
+
+    outb(0x43, 0x36);
+    outb(0x40, (unsigned char)(divisor & 0xFF));
+    outb(0x40, (unsigned char)((divisor >> 8) & 0xFF));
+}
+
+unsigned long timer_ticks(void) {
+    return g_ticks;
+}
+
+void timer_tick_advance(void) {
+    ++g_ticks;
+}
+
+void timer_sleep_ms(unsigned long ms) {
+    if (!interrupts_enabled()) {
+        busy_delay_ms(ms);
+        return;
+    }
+
+    unsigned long start = timer_ticks();
+    unsigned long wait_ticks = (ms + 9UL) / 10UL;
+
+    if (wait_ticks == 0) {
+        wait_ticks = 1;
+    }
+
+    while ((timer_ticks() - start) < wait_ticks) {
+        __asm__ volatile ("hlt");
+    }
+}