added timer config and setup (PIT)

4 files changed, 115 insertions, 67 deletions

diff --git a/Makefile b/Makefile
index 297e6a0..4bb9b25 100644
--- a/Makefile
+++ b/Makefile
@@ -41,7 +41,10 @@ interrupts.o: kernel/interrupts.c kernel/interrupts.h
 keyboard.o: kernel/keyboard.c 
 	gcc -ffreestanding -m32 -o $@ -c $< -fno-asynchronous-unwind-tables -O0
 
-kernel.bin: kernel_entry.o kernel.o console.o interrupts.o keyboard.o
+timer.o: kernel/timer.c
+	gcc -ffreestanding -m32 -o $@ -c $< -fno-asynchronous-unwind-tables -O0
+
+kernel.bin: kernel_entry.o kernel.o console.o interrupts.o keyboard.o timer.o
 	ld -o $@ -Ttext 0x1000 --oformat binary -melf_i386 $^ -O0
 
 
diff --git a/kernel/console.c b/kernel/console.c
index 70076d5..8ca7ae2 100644
--- a/kernel/console.c
+++ b/kernel/console.c
@@ -17,7 +17,7 @@ void print_char(int x, int y, char c)
     print_char_col(x,y,c,SCR_WHITE);
 }
 
-void print_single_hex(int i)
+void print_single_num(int i)
 {
    if(i<10)print_char_col(posx,posy,'0'+i,SCR_GREEN); 
    else if(i<16)print_char_col(posx,posy,'A'+i-10,SCR_GREEN); 
@@ -62,7 +62,7 @@ void scr_clear()
 void scr_put_string_nl(char *str)
 {
     scr_put_string(str);
-    scr_nextline;
+    scr_nextline();
 }
 
 void scr_nextline()
@@ -83,6 +83,13 @@ void scr_nextline()
 		char* video_mem2=(char *)SCR_VIDEOMEM+((x)+i*SCR_REAL_WIDTH)*2;
 		*video_mem=*video_mem2;
 		*(video_mem+1)=*(video_mem2+1);
+		//clear  last line
+		if(i==SCR_HEIGHT-2)
+		{
+		    print_char_col(x,i,'@',SCR_LBLUE);
+		    
+
+		}
 	    }
 	}
 
@@ -106,7 +113,7 @@ void scr_put_hex(uint16_t val)
 
     for(i=0;i<4;i++)
     {
-	print_single_hex((val&0xf000)>>12);
+	print_single_num((val&0xf000)>>12);
 	val=val << 4;
 
     }
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 7d845c5..3c7b578 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -3,47 +3,10 @@
 
 // TODO: cleanup . how can i compile it without the includes!??
 
-
-/// PIT /// Timer stuff
-
-/*
- http://www.brokenthorn.com/Resources/OSDevPit.html
-
- vcc/gnd - voltage/ground
-
- D0-D7 - data lines		(data bus)
- wr/rd - writing / reading	(system control bus) 
- cs - ignore wr/rd or not	(address bus)
- a0-a1				(address bus)
-
- // the three 16bit down counters/timers/channels
- clk	0-2 (in)
- gate	0-2 (in)
- out	0-2 (out)
-
-
-
-
- //typical
-    out1 -> pic  interrupt on every tick (system timer)
-    out2 - was used for genearting dram memory refresh  (Do not use)
-    out3 -> pc speaker
-
-    gate pins : depend on mode of operation
-    we do have modes 0-5.
-
-
- */
-
-
-
-
-
-
-
 ///////
 
 void int_kb_handler();
+void int_clock_handler();
 ////////// KERNEL MAIN///// /////
 //
 
@@ -52,7 +15,7 @@ void int_test_handler()
 {
     __asm__("pusha");
 
-    scr_put_string_nl("inside software interrupt handler 88");
+    scr_put_string("inside software interrupt handler 88");
 
 
     __asm__("popa");
@@ -61,27 +24,6 @@ void int_test_handler()
 
 }
 
-// clock handler
-void int_clock_handler()
-{
-    __asm__("pusha");
-
-    scr_put_string_nl(".");
-
-
-    // todo also the other pic!// TODO
-    __asm__("mov $0x20, %al");
-    __asm__("out %al, $0x20");
-    //
-
-    __asm__("popa");
-    __asm__("leave");
-    __asm__("iret");
-    __asm__("popa");
-    __asm__("leave");
-    __asm__("iret");
-
-}
 void kernel_main()
 {
     
@@ -91,11 +33,16 @@ void kernel_main()
     // hello message
     scr_put_string_nl(KERNEL_HELLO_MESSAGE);
     
-    // init interrupt decriptor table 
-    // install and enable!
+    //pit config
+    timer_init();
+    scr_put_string_nl("Configured PIT Channel 0 : Mode 2 : 1/25 s.");
+
+
+    // init and interrupt decriptor table 
     int_init(0x08);
     int_install();
 
+    // setup custom interrupts
     // remember that we shifted all interrupts with the pic by 32
     // so clock = 32 (irq 0)
     // keyboard = 22 (irq 1)
@@ -112,12 +59,12 @@ void kernel_main()
 
     // now we can enable interrupts back again
     int_enable();
-
     scr_put_string_nl("Interrupts are up and running");
 
     // kernel main loop
     while(1)
     {
+
 	
     }
  
diff --git a/kernel/timer.c b/kernel/timer.c
new file mode 100644
index 0000000..1f97c92
--- /dev/null
+++ b/kernel/timer.c
@@ -0,0 +1,91 @@
+
+/// PIT /// Timer stuff
+
+/*
+ http://www.brokenthorn.com/Resources/OSDevPit.html
+
+ vcc/gnd - voltage/ground
+
+ D0-D7 - data lines		(data bus)
+ wr/rd - writing / reading	(system control bus) 
+ cs - ignore wr/rd or not	(address bus)
+ a0-a1				(address bus)
+
+ // the three 16bit down counters/timers/channels
+ clk	0-2 (in)
+ gate	0-2 (in)
+ out	0-2 (out)
+
+ //typical
+    out1 -> pic  interrupt on every tick (system timer)
+    out2 - was used for genearting dram memory refresh  (Do not use)
+    out3 -> pc speaker
+
+    gate pins : depend on mode of operation
+    we do have modes 0-5.
+    mode0: counts down to zero , triggers interrupt and waits 
+    mode1: 
+    mode2: rate generator (sys timer)
+    ....
+
+
+ */
+
+#include "kernel.h"
+
+static uint64_t timer64=0;
+static uint8_t timer8=0;
+
+// clock handler
+void int_clock_handler()
+{
+    __asm__("pusha");
+
+    
+    timer64++;
+    timer8++;
+
+    // show point once every 1 second
+    if(timer8==25)
+    {
+	scr_put_string(".");
+	timer8=0;
+    }
+
+
+    // todo also the other pic!// TODO
+    __asm__("mov $0x20, %al");
+    __asm__("out %al, $0x20");
+    //
+
+    __asm__("popa");
+    __asm__("leave");
+    __asm__("iret");
+    __asm__("popa");
+    __asm__("leave");
+    __asm__("iret");
+
+}
+
+void timer_init()
+{
+    // config out timer on channel 0 : mode 2 (sys timer)
+    // http://en.wikipedia.org/wiki/Intel_8253#Control_Word_Register
+    // http://www.brokenthorn.com/Resources/OSDevPit.html
+    // int0 will be triggered ~25 times a second.
+
+    __asm__("pusha");
+
+    __asm__("mov %0, %%dx"::"X" (1193180 / 25));
+
+    __asm__("mov $0b00110100, %al");
+    __asm__("out %al,$0x43");
+
+    __asm__("mov %dx,%ax");
+
+    __asm__("out %al, $0x40");
+    __asm__("xchg %ah,%al");
+    __asm__("out %al, $0x40");
+
+    __asm__("popa");
+}