1.1 --- a/src/intr.c	Fri May 27 13:08:23 2011 +0300
     1.2 +++ b/src/intr.c	Sat May 28 08:06:47 2011 +0300
     1.3 @@ -156,7 +156,7 @@
     1.4  	desc->d[3] = (addr & 0xffff0000) >> 16;
     1.5  }
     1.6  
     1.7 -#define IS_TRAP(n)	((n) < 32)
     1.8 +#define IS_TRAP(n)	((n) >= 32 && !IS_IRQ(n))
     1.9  static void set_intr_entry(int num, void (*handler)(void))
    1.10  {
    1.11  	int type = IS_TRAP(num) ? GATE_TRAP : GATE_INTR;

     2.1 --- a/src/main.c	Fri May 27 13:08:23 2011 +0300
     2.2 +++ b/src/main.c	Sat May 28 08:06:47 2011 +0300
     2.3 @@ -66,26 +66,6 @@
     2.4  	/* initialization complete, enable interrupts */
     2.5  	enable_intr();
     2.6  
     2.7 -	dbg_print_vm(MEM_USER);
     2.8 -	dbg_print_vm(MEM_KERNEL);
     2.9 -
    2.10 -	{
    2.11 -		void *foo, *bar, *xyzzy, *koko, *lala;
    2.12 -
    2.13 -		foo = malloc(128);
    2.14 -		bar = malloc(32 * 1024);
    2.15 -		xyzzy = malloc(8000);
    2.16 -
    2.17 -		free(bar);
    2.18 -
    2.19 -		koko = malloc(700);
    2.20 -		lala = malloc(6 * 1024 * 1024);
    2.21 -
    2.22 -		free(xyzzy);
    2.23 -		free(foo);
    2.24 -		free(koko);
    2.25 -		free(lala);
    2.26 -	}
    2.27  
    2.28  	for(;;) {
    2.29  		char c, keypress;

     3.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     3.2 +++ b/src/proc.h	Sat May 28 08:06:47 2011 +0300
     3.3 @@ -0,0 +1,14 @@
     3.4 +#ifndef PROC_H_
     3.5 +#define PROC_H_
     3.6 +
     3.7 +#include "tss.h"
     3.8 +
     3.9 +struct process {
    3.10 +	int id;
    3.11 +
    3.12 +	struct task_state tss;
    3.13 +
    3.14 +	struct process *next;
    3.15 +};
    3.16 +
    3.17 +#endif	/* PROC_H_ */

     4.1 --- a/src/segm.c	Fri May 27 13:08:23 2011 +0300
     4.2 +++ b/src/segm.c	Sat May 28 08:06:47 2011 +0300
     4.3 @@ -11,6 +11,8 @@
     4.4  #define BIT_CODE		(1 << 11)
     4.5  #define BIT_NOSYS		(1 << 12)
     4.6  #define BIT_PRESENT		(1 << 15)
     4.7 +/* TSS busy bit */
     4.8 +#define BIT_BUSY		(1 << 9)
     4.9  
    4.10  /* bits for the last 16bit part of the descriptor */
    4.11  #define BIT_BIG			(1 << 6)
    4.12 @@ -19,7 +21,11 @@
    4.13  
    4.14  enum {TYPE_DATA, TYPE_CODE};
    4.15  
    4.16 +#define TSS_TYPE_BITS	0x900
    4.17 +#define TSS_BUSY		BIT_BUSY
    4.18 +
    4.19  static void segm_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, int type);
    4.20 +static void task_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, unsigned int busy);
    4.21  
    4.22  /* these functions are implemented in segm-asm.S */
    4.23  void setup_selectors(uint16_t code, uint16_t data);
    4.24 @@ -27,7 +33,7 @@
    4.25  
    4.26  
    4.27  /* our global descriptor table */
    4.28 -static desc_t gdt[3];
    4.29 +static desc_t gdt[6];
    4.30  
    4.31  
    4.32  void init_segm(void)
    4.33 @@ -35,6 +41,9 @@
    4.34  	memset(gdt, 0, sizeof gdt);
    4.35  	segm_desc(gdt + SEGM_KCODE, 0, 0xffffffff, 0, TYPE_CODE);
    4.36  	segm_desc(gdt + SEGM_KDATA, 0, 0xffffffff, 0, TYPE_DATA);
    4.37 +	segm_desc(gdt + SEGM_UCODE, 0, 0xffffffff, 3, TYPE_CODE);
    4.38 +	segm_desc(gdt + SEGM_UDATA, 0, 0xffffffff, 3, TYPE_DATA);
    4.39 +	/*task_desc(gdt + SEGM_TASK, 0, 0xffffffff, 3, TSS_BUSY);*/
    4.40  
    4.41  	set_gdt((uint32_t)gdt, sizeof gdt - 1);
    4.42  
    4.43 @@ -64,3 +73,13 @@
    4.44  	 */
    4.45  	desc->d[3] = ((limit >> 16) & 0xf) | ((base >> 16) & 0xff00) | BIT_GRAN | BIT_BIG;
    4.46  }
    4.47 +
    4.48 +static void task_desc(desc_t *desc, uint32_t base, uint32_t limit, int dpl, unsigned int busy)
    4.49 +{
    4.50 +	desc->d[0] = limit & 0xffff;
    4.51 +	desc->d[1] = base & 0xffff;
    4.52 +
    4.53 +	desc->d[2] = ((base >> 16) & 0xff) | ((dpl & 3) << 13) | BIT_PRESENT |
    4.54 +		TSS_TYPE_BITS | busy;
    4.55 +	desc->d[3] = ((limit >> 16) & 0xf) | ((base >> 16) & 0xff00) | BIT_GRAN;
    4.56 +}

     5.1 --- a/src/segm.h	Fri May 27 13:08:23 2011 +0300
     5.2 +++ b/src/segm.h	Sat May 28 08:06:47 2011 +0300
     5.3 @@ -3,6 +3,9 @@
     5.4  
     5.5  #define SEGM_KCODE	1
     5.6  #define SEGM_KDATA	2
     5.7 +#define SEGM_UCODE	3
     5.8 +#define SEGM_UDATA	4
     5.9 +#define SEGM_TASK	5
    5.10  
    5.11  void init_segm(void);
    5.12  

     6.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     6.2 +++ b/src/tss.h	Sat May 28 08:06:47 2011 +0300
     6.3 @@ -0,0 +1,21 @@
     6.4 +#ifndef TSS_H_
     6.5 +#define TSS_H_
     6.6 +
     6.7 +#include <inttypes.h>
     6.8 +
     6.9 +struct task_state {
    6.10 +	uint32_t prev_task;
    6.11 +	uint32_t esp0, ss0;
    6.12 +	uint32_t esp1, ss1;
    6.13 +	uint32_t esp2, ss2;
    6.14 +	uint32_t cr3;
    6.15 +	uint32_t eip;
    6.16 +	uint32_t eflags;
    6.17 +	uint32_t eax, ecx, edx, ebx;
    6.18 +	uint32_t esp, ebp, esi, edi;
    6.19 +	uint32_t es, cs, ss, ds, fs, gs;
    6.20 +	uint32_t ldt_sel;
    6.21 +	uint16_t trap, iomap_addr;
    6.22 +} __attribute__((packed));
    6.23 +
    6.24 +#endif	/* TSS_H_ */