From c0df0ee6437aa2786b1a92bc6af1284958d104c7 Mon Sep 17 00:00:00 2001
From: Franklin Wei <frankhwei536@gmail.com>
Date: Sat, 7 Feb 2015 11:03:48 -0500
Subject: new rng, some rework of I/O

---
 kernel/include/log.h   |  4 ++--
 kernel/include/timer.h |  9 +++++++--
 kernel/log.c           |  6 ++----
 kernel/main.c          | 11 ++++++++---
 kernel/timer.c         | 24 +++++++++++++++++++++---
 5 files changed, 40 insertions(+), 14 deletions(-)

(limited to 'kernel')

diff --git a/kernel/include/log.h b/kernel/include/log.h
index fb29dd3..6953bee 100644
--- a/kernel/include/log.h
+++ b/kernel/include/log.h
@@ -1,3 +1,3 @@
-int log_putchar(char);
-int log_puts(const char*);
+void log_putchar(char);
+void log_puts(const char*);
 void log(const char*, ...);
diff --git a/kernel/include/timer.h b/kernel/include/timer.h
index a7459a6..bf2eddd 100644
--- a/kernel/include/timer.h
+++ b/kernel/include/timer.h
@@ -1,7 +1,12 @@
 #include <stdint.h>
 
-extern const uint64_t *current_tick;
+#define HZ 100
+#define PIT_FREQ 1193182
+
+extern volatile const uint64_t *current_tick;
 
 struct regs_t;
 
-void timer_init(void);
+void timer_init(uint32_t freq);
+
+void timer_delay(uint64_t ticks);
diff --git a/kernel/log.c b/kernel/log.c
index 3f509c5..efc945d 100644
--- a/kernel/log.c
+++ b/kernel/log.c
@@ -5,17 +5,15 @@
 
 #define BOCHS_PUTCHAR(ch) (outb(0xe9, ch))
 
-int log_putchar(int ch)
+void log_putchar(int ch)
 {
     BOCHS_PUTCHAR(ch);
-    return 0;
 }
 
-int log_puts(const char* str)
+void log_puts(const char* str)
 {
     while(*str)
         log_putchar(*str++);
-    return 0;
 }
 
 static char hex_table[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
diff --git a/kernel/main.c b/kernel/main.c
index 9082859..d791da1 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -1,11 +1,13 @@
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include "gdt.h"
 #include "idt.h"
 #include "isr.h"
 #include "irq.h"
 #include "log.h"
 #include "multiboot.h"
+#include "panic.h"
 #include "pcspkr.h"
 #include "ps2.h"
 #include "timer.h"
@@ -36,15 +38,18 @@ void main(struct multiboot_info_t *hdr, uint32_t magic)
     irq_init();
 
     /* initialize other drivers */
-    timer_init();
+    timer_init(HZ);
     ps2_init();
 
     asm("sti");
 
     printf("Boot finished.\n");
 
-    for(int i=0;i<50;++i)
-        vga_drawpixel(i, i, VGA_RGBPACK(255, 0, 0));
+    printf("Testing RNG...\n");
+    srand(*current_tick);
+
+    for(int i=0;i>=0;++i)
+        vga_drawpixel(rand() % *vga_width, rand() % *vga_height, rand() % 0xFFFFFF);
 
     printf("Testing keyboard LED's...\n");
 
diff --git a/kernel/timer.c b/kernel/timer.c
index 571fcbe..2fbd8eb 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1,10 +1,11 @@
 #include <stdint.h>
+#include "io.h"
 #include "isr.h"
 #include "timer.h"
 
-uint64_t current_tick_data = 0;
+volatile uint64_t current_tick_data = 0;
 
-const uint64_t *current_tick = &current_tick_data;
+volatile const uint64_t *current_tick = &current_tick_data;
 
 static void timer_callback(struct regs_t regs)
 {
@@ -12,7 +13,24 @@ static void timer_callback(struct regs_t regs)
     ++current_tick_data;
 }
 
-void timer_init(void)
+void timer_init(uint32_t freq)
 {
     set_interrupt_handler(IRQ(0), timer_callback);
+
+    current_tick_data = 0;
+
+    uint32_t divisor = PIT_FREQ / freq;
+
+    uint8_t hi = (divisor >> 8) & 0xFF;
+    uint8_t lo = (divisor >> 0) & 0xFF;
+
+    outb(0x43, 0x36);
+    outb(0x40, lo);
+    outb(0x40, hi);
+}
+
+void timer_delay(uint64_t ticks)
+{
+    uint64_t end = *current_tick + ticks;
+    while(*current_tick <= end);
 }
-- 
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