Timer

source/kernel/idt.c

@@ -19,39 +19,6 @@ __attribute__((aligned(0x10))) static idt_entry_t idt[NUM_IDTS];
 // define the idtr
 static idtr_t idtr;
 
-static uint32_t has_triggered = 0;
-static uint32_t hits = 0;
-static uint32_t oopsie_woopsie = 0;
-
-uint32_t get_hits(void) { return oopsie_woopsie; }
-
-// we no-inline because I don't want it inlined :lemonthink:
-// also i want the actual isr to only have save register, call, then iret
-__attribute__((noinline)) static void actual_exception_handler(void)
-{
-    oopsie_woopsie++;
-}
-
-// this currently will triple-fault on pressing a keyboard
-__attribute__((noinline)) static void actualirq1Handler(void)
-{
-    // seems to triple fault before reaching here, idk pls can we get serial
-    // driver
-    hits++;
-    if (terminal_driver_loaded() && !has_triggered) {
-        terminal_putchar('U');
-        terminal_update_cursor();
-        // inb(0x60) is the port containing the key pressed
-        terminal_put64(inb(0x60));
-        terminal_update_cursor();
-
-        // send eoi to the master PIC
-        // this is needed in the PIC remapping, don't question it
-        outb(0x20, 0x20);
-        __asm__ volatile("cli");
-    }
-}
-
 void idt_set_entry(int idx, uint32_t handler_ptr, uint16_t code_selector,
                    uint8_t attributes)
 {
@@ -109,7 +76,7 @@ void setup_pic(void)
     //
     // remember that ^ toggles bits, so bits 1 and 2 will be toggled to 0
     // (which will enable them in hw)
-    mask1 = 0xff ^ (1 << 1 | 1 << 2);
+    mask1 = 0xff ^ (1 << 0 | 1 << 1 | 1 << 2);
     mask2 = 0xff;
     outb(0x21, mask1);
     io_wait();

source/kernel/include/timer.h

@@ -1,4 +1,6 @@
 #pragma once
 #include <stdint.h>
+#include "idt.h"
 
-unsigned long long get_cpu_time();
+void timer_init(uint32_t hz);
+void timer_irq(registers_t *frame);

source/kernel/isr.c

@@ -3,6 +3,7 @@
 #include "io.h"
 #include "keyboard_driver.h"
 #include "terminal_driver.h"
+#include "timer.h"
 
 isr_t interrupt_handlers[256];
 
@@ -21,6 +22,8 @@ void breakpoint(registers_t *frame) { printf("breakpoint\n"); }
 
 void overflow(registers_t *frame) { printf("overflow trap\n"); }
 
+void pagefault(registers_t *frame) { printf("page fault\n"); }
+
 void init_isr()
 {
     for (int i = 0; i < 256; i++)
@@ -31,11 +34,13 @@ void init_isr()
     register_interrupt_handler(3, &breakpoint);
     register_interrupt_handler(4, &overflow);
 
-    // irq handlers
-    register_interrupt_handler(33, &keyboard_irq);
+    register_interrupt_handler(14, &pagefault);
 
-    // handler initializations
+    // irq handlers IRQ# + 32
+    timer_init(100);
+    register_interrupt_handler(32, &timer_irq);
     keyboard_init();
+    register_interrupt_handler(33, &keyboard_irq);
 }
 
 void isr_handler(registers_t *frame)

source/kernel/kernel.c

@@ -12,32 +12,10 @@ void main()
 {
     init_drivers();
     terminal_clear();
-    init_paging();
     terminal_update_cursor();
     init_idt();
-    asm volatile("int $0x3");
-    asm volatile("int $0x4");
+    init_paging();
+    printf("Hello");
 
     write_serial(COM1, "Hello From SecureOS!");
-    // printf(s.data);
-
-    // init_paging();
-    // string s;
-    // s.data =
-    // "HEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEELLLLLLLLLLLLLLLLLLLLLLLLLLL"
-    //          "LLOOOOOOOOOOOOOOOOOOOOOOOOOOOOO";
-    // s.len = 96;
-    // printf(&s);
-    // uint32_t* wow = (uint32_t*) 0x12340000;
-    // palloc(wow, PAGE_PRESENT | PAGE_RW);
-    // *wow = 0x42042069;
-    // terminal_put64(*wow);
-    // for (int i = 0; i < 30; i ++) {
-    //     uint32_t* smol = kalloc(200);
-    //     *smol = 0x12345678;
-    //     terminal_put64(smol);
-    //     terminal_putchar(' ');
-    //     terminal_put64(*smol);
-    //     terminal_putchar('\n');
-    // }
 }

source/kernel/kernel_entry.asm

@@ -6,7 +6,7 @@ global kernel_entry
 
 ; flags for a megapage
 MEGAPAGE_FLAGS equ (1 << 7) | (1 << 1) | (1 << 0)
-L2_PAGE_BASE equ l2_page_table - (1 << 31)
+L2_PAGE_BASE equ l2_page_table - (0x80100000)
 
 kernel_entry:
 ; enable page size extensions

source/kernel/memory.c

@@ -1,7 +1,7 @@
 #include "memory.h"
 #include "terminal_driver.h"
+#include "io.h"
 #include <stdint.h>
-#include <stdlib.h>
 
 uint32_t l2_page_table[1024] __attribute__((aligned(4096)));
 

source/kernel/timer.c

@@ -1,12 +1,49 @@
 #include "timer.h"
+#include "io.h"
 
-unsigned long long get_cpu_time()
-{
-    unsigned long long time_stamp;
-    // get time_stamp from cpu register
-    asm volatile("rdtsc" : "=A"(time_stamp));
+#define PORT_CHANNEL_0 0x40
+#define PORT_CHANNEL_1 0x41
+#define PORT_CHANNEL_2 0x42
+#define PORT_CMD 0x43
 
-    return time_stamp;
+// Channel options
+#define CHANNEL_0 (0b00 << 6)
+#define CHANNEL_1 (0b01 << 6)
+#define CHANNEL_2 (0b10 << 6)
+#define READ_BACK (0b11 << 6)
+
+// Access mode options
+#define LATCH_COUNT (0b00 << 4)
+#define LOBYTE_ONLY (0b01 << 4)
+#define HIBYTE_ONLY (0b10 << 4)
+#define LOBYTE_HIBYTE (0b11 << 4)
+
+// Operating mode options
+#define MODE_0 (0b000 << 1) //interrupt on terminal count
+#define MODE_1 (0b001 << 1) //hardware retriggerable one-shot
+#define MODE_2 (0b010 << 1) //rate generator
+#define MODE_3 (0b011 << 1) //square wave generator
+#define MODE_4 (0b100 << 1) //software strobe
+#define MODE_5 (0b101 << 1) //hardware strobe
+
+// BCD/Binary mode options
+#define BINARY_MODE 0
+#define BCD_MODE 1
+
+uint32_t divisor;
+uint32_t tick;
+
+void timer_init(uint32_t hz) {
+    tick = 0;
+    divisor = 1193180 / hz;
+    outb(PORT_CMD, CHANNEL_0 | LOBYTE_HIBYTE | MODE_3 | BINARY_MODE);
+    uint8_t lowbyte = (uint8_t) (divisor & 0xFF);
+    uint8_t highbyte = (uint8_t) ((divisor >> 8) & 0xFF);
+    outb(PORT_CHANNEL_0, lowbyte);
+    outb(PORT_CHANNEL_0, highbyte);
 }
 
-unsigned long long get_cpu_frequency() {}
+void timer_irq(registers_t *frame) {
+    tick++;
+    // printf("%x\n", tick);
+}