Cleaning code

src/bringelle.c

@@ -8,29 +8,32 @@
 extern void interrupt_enable();
 
 void utask(){
-  char *msg=(char*)4206592+10;
+  char *msg=(char*)4206592+300;
   msg[0]='A';
   msg[1]='\0';
   while(1){
       asm("mov $0x1, %%eax;int $0x30"::"b"(msg));
-      for(int i=0;i<10000;i++){
+      for(int i=0;i<5000;i++){
 
       }
   }
 }
 
 void utask2(){
-  char *msg=(char*)4206592+10;
+  char *msg=(char*)4206592+300;
   msg[0]='B';
   msg[1]='\0';
   while(1){
       asm("mov $0x1, %%eax;int $0x30"::"b"(msg));
-      for(int i=0;i<10000;i++){
+      for(int i=0;i<5000;i++){
         
       }
   }
 }
 
+/**
+ * Kernel entry point
+ */
 void bringelle(){
   clear();
   printc("Booting Bringelle...\n",GREEN);
@@ -51,6 +54,7 @@ void bringelle(){
   int* page_dir=paging_allocate(2);
   task_create(page_dir, utask,100, 0xFF);
 
+
   int* page_dir2=paging_allocate(2);
   task_create(page_dir2, utask2,100,0xFF);
 

src/core/paging.c

@@ -1,5 +1,6 @@
 #include "paging.h"
 #include "libc/stdio.h"
+#include "libc/math.h"
 
 /// Use a bitmap to keep track of allocated pages
 char pages_status[PAGING_MAX_PAGES/8];
@@ -105,11 +106,24 @@ int *paging_allocate(int p){
   
     // ----- Task table
     int *u_page_table=(int*)paging_allocate_next_page();
-    page_dir[1]=(int)u_page_table|7; // 1024*1024*4096/4
+    page_dir[1]=(int)u_page_table|7;
-    u_page_table[0]=(int)page_dir|7;
+    u_page_table[0]=(int)page_dir|7; // Virtual address is 1024*4096/4
     u_page_table[1]=(int)k_page_table|7;
     u_page_table[2]=(int)u_page_table|7;
-    u_page_table[3]=(int)paging_allocate_next_page()|7;
+
+    int dir_entry=1;
+    int pt_entry=3;
+    int p_current=max(1,p); // Allocate at least 1 page
+    while(p_current!=0){
+        if(pt_entry%1024==0){
+            dir_entry++;
+            pt_entry=0;
+            u_page_table=(int*)paging_allocate_next_page();
+            page_dir[dir_entry]=(int)u_page_table|7;
+        }
+        u_page_table[pt_entry]=(int)paging_allocate_next_page()|7;
+        p_current--;
+    }
     
     return page_dir;
 }

src/core/paging.h

@@ -13,30 +13,35 @@
 #define PAGING_ENTRY_POINT_VIRT (1024*PAGING_PAGE_SIZE+3*PAGING_PAGE_SIZE)
 #define PAGING_ENTRY_POINT_PHY(page_dir) ((int*)(((int*)((((int*)page_dir)[1])&0xFFFFF000))[3]&0xFFFFF000))
 
-
-
-
-
 /**
  * Configure and enable paging
  */
 void paging_enable();
+
 /**
  * Allocate a new page and return its address
  */
 char* paging_allocate_next_page();
+
 /**
  * Set usage status of a page
  */
 void paging_set_usage(int addr,char state);
+
 /**
  * Create a new page directory containing
  * p pages.
  */
 int *paging_allocate(int p);
+
+/**
+ * Simple dump
+ */
 void paging_dump(int min,int max);
+
 /**
  * Handler of page fault
  */
 void paging_page_fault();
+
 #endif

src/core/scheduler.c

@@ -123,19 +123,25 @@ void task_create(int *page_dir, void *task, int task_size, int stack_offset){
 
 void scheduler_start(){
   if(nproc>0){
+    // Disable interrupt to not be interrupted
     asm("cli");
-    scheduler_on=1; // Enable scheduling
+    // Enable scheduling
+    scheduler_on=1;
+
+    // Save kernel stack state
     u32 *stack;
     asm("mov %%ebp, %0":"=r" (stack));
-    TSS.esp0=(u32)stack+1; // Remove ebp (c call convention)
+    // Remove ebp from the (c call convention) and return address (call)
+    TSS.esp0=(u32)stack+2;
     asm("mov %%ss, %0": "=m" (TSS.ss0));
 
-    current_id=1;
+    // Get first stack
+    current_id=0;
     PROC *p=&procs[current_id];
-
     // Ensure interrupts are activated and NT flag is clear
     p->regs.eflags|=0x200;
     p->regs.eflags&=0xffffbfff;
+    // Switch to user task
     asm(
       "push %0    \n\t"
       "jmp task_switch"

src/core/scheduler.h

@@ -35,6 +35,7 @@ extern u16 nproc; // Number of active tasks
  * Must be called at each clock interrupt
  */
 void clock();
+
 /**
  * Called by clock() and schedule the next task
  * Stack is a pointer pointing to the gs register on the stack.
@@ -42,10 +43,12 @@ void clock();
  * order: gs,fs,es,ds,edi,esi,ebp,UNUSED,edx,ecx,ebx,eax,eip,cs,eflags,esp,ss
  */
 void schedule(u32 *stack);
+
 /**
  * Create a new task to be schedule
  */
 void task_create(int *page_dir, void *task, int task_size, int stack_offset);
+
 /**
  * Stack the scheduler starting by task with PID 0
  */

src/drivers/pic.h

@@ -2,7 +2,7 @@
 #define PIC_H
 
 /**
- * Configure 
+ * Configure the PIC
  */
 void pic_init();
 

src/libc/math.h

@@ -5,4 +5,5 @@ int pow(int x,int n);
 int max(int x,int y);
 int min(int x,int y);
 int abs(int x);
+
 #endif

src/libc/stdio.h

@@ -3,8 +3,19 @@
 
 #include "drivers/framebuffer.h"
 
+/**
+ * Print a char* in the framebuffer
+ */
 void print(char*);
+
+/**
+ * Print a char in the framebuffer
+ */
 void printc(char*,VIDEO_COLORS c);
+
+/**
+ * Print an integer using itoa()
+ */
 void printi(int i);
 
 #endif

src/libc/string.h

@@ -1,6 +1,9 @@
 #ifndef STRING_H
 #define STRING_H
 
+/**
+ * Convert int to char
+ */
 void itoa(int i, char *a);
 
 #endif