add fork

am/am.h

@@ -93,7 +93,7 @@ extern _Screen _screen;
 void _asye_init();
 void _listen(_RegSet* (*l)(_Event ev, _RegSet *regs));
 _RegSet *_make(_Area kstack, void *entry);
-void _trap();
+int _trap(int num, int check, u32 args1, u32 args2);
 void _idle();
 void _ienable();
 void _idisable();

am/arch/x86-qemu/src/asye.cpp

@@ -6,6 +6,7 @@
 extern "C" { int printk(const char *, ...); }
 
 static _RegSet* (*H)(_Event, _RegSet*) = nullptr;
+static u32 args[4];
 
 extern "C" {
 void irq0();
@@ -60,7 +61,14 @@ void irq_handle(TrapFrame *tf) {
   ev.event = _EVENT_NULL;
   if (tf->irq == 32) ev.event = _EVENT_IRQ_TIME;
   else if (tf->irq == 33) ev.event = _EVENT_IRQ_IODEV;
-  else if (tf->irq == 0x80) ev.event = _EVENT_SYSCALL;
+  else if (tf->irq == 0x80) {
+    ev.event = _EVENT_SYSCALL;
+    args[0] = regs.eax;
+    args[1] = regs.edx;
+    args[2] = regs.ecx;
+    args[3] = regs.ebx;
+    ev.cause = args;
+  }
   else if (tf->irq < 32) ev.event = _EVENT_ERROR;
 
   _RegSet *ret = &regs;
@@ -216,8 +224,9 @@ _RegSet *_make(_Area stack, void *entry) {
   return regs;
 }
 
-void _trap() {
-  asm volatile("int $0x80");
+int _trap(int num, int check, u32 args1, u32 args2) {
+  asm volatile("int $0x80"::"a"(num),"d"(check),"c"(args1),"b"(args2));
+  return args[0];
 }
 
 void _idisable() {

apps/nanos/include/irq.h

@@ -0,0 +1,6 @@
+#ifndef __IRQ_H__
+#define __IRQ_H__
+
+_RegSet* handle(_Event ev, _RegSet *r);
+
+#endif

apps/nanos/include/pcb.h

@@ -5,7 +5,7 @@
 #include <klib.h>
 #include "list.h"
 
-#define NR_PCBS 3
+#define NR_PCBS 10
 #define SLEEP 1
 #define READY 0
 #define FREE 2
@@ -31,6 +31,7 @@ extern u16 pcb_avls;
 
 void init_idle();
 PCB *create_kthread(size_t entry);
+void schedule();
 int sys_fork();
 void sys_sleep();
 void sys_wakeup(u32 time);

apps/nanos/src/apps/main.c

@@ -1,8 +1,40 @@
 #include <am.h>
 #include <klib.h>
 
+/*void do_child() {
+  int i;
+  for(i = 0; i < 10; i++){
+    printf("Pang ");
+    printf("now sleep for %ds\n",1);
+    sleep(1);
+  }
+}
+
+void do_father() {
+  int i;
+  for(i = 0; i < 10; i++){
+    printf("Ping ");
+    printf("now sleep for %ds\n",1);
+    sleep(1);
+  }
+}*/
+
 int umain(){
-  printk("jump into umain");
+  printf("jump into umain\n");
+  unsigned int fpid = 0;
+  fpid = fork();
+  if(fpid < 0)
+    printf("error in fork\n");
+  if(fpid == 0){
+    printf("father = %d\n",fpid);
+    //do_father();
+  }
+  else{
+    printf("child = %d\n",fpid);
+    //do_child();
+  }
+  printf("main end , return to idle\n");
+  //exit(0);
   while(1);
   return 0;
 }

apps/nanos/src/kernel/do_irq.c

@@ -0,0 +1,30 @@
+#include <am.h>
+#include <klib.h>
+#include "irq.h"
+#include "pcb.h"
+
+void do_syscall(_Event ev, _RegSet *r){
+  int *args = ev.cause;
+  switch(args[0]){
+    case 20:args[0] = sys_fork();break;
+    default:_halt(args[0]);
+  }
+}
+
+_RegSet* handle(_Event ev, _RegSet *r){
+  switch(ev.event){
+    case _EVENT_IRQ_TIME: {
+      memcpy(current->sf, r, sizeof(struct _RegSet));
+      if(current->time_count == 0){
+        schedule();
+      }
+      else{
+        _putc('-');
+        current->time_count--;
+      }
+      return current->sf;
+    }
+    case _EVENT_SYSCALL:do_syscall(ev, r);return r;
+    default:_halt(ev.event);return r;
+  }
+}

apps/nanos/src/kernel/proc.c

@@ -1,6 +1,7 @@
 #include <am.h>
 #include <klib.h>
 #include "pcb.h"
+#include "irq.h"
 
 PCB PCBs[NR_PCBS];
 PCB *current;
@@ -10,25 +11,6 @@ LIST_HEAD(blockq_h);
 u16 pcb_avls = 0;	//pcb available index
 _Area stack;
 
-extern void schedule();
-
-_RegSet* handle(_Event ev, _RegSet *r){
-  switch(ev.event){
-    case _EVENT_IRQ_TIME: {
-      memcpy(current->sf, r, sizeof(struct _RegSet));
-      if(current->time_count == 0){
-        schedule();
-      }
-      else{
-        _putc('-');
-        current->time_count--;
-      }
-      return current->sf;
-    }
-    default:_halt(ev.event);return r;
-  }
-}
-
 void init_idle(){
   PCB *pcb = &(PCBs[pcb_avls]);
   current = pcb;
@@ -58,8 +40,26 @@ PCB *create_kthread(size_t entry){
   pcb->sleep_time = 0;
 
   pcb->state = READY;
-  strcpy(pcb->name,"PCB");
+  strcpy(pcb->name,"PCB0");
   pcb_avls++;
   list_add(&(pcb->state_list),&readyq_h);
   return pcb;
 }
+
+int sys_fork(){
+  assert(pcb_avls < NR_PCBS);
+  PCB *pcb = &(PCBs[pcb_avls]);
+  pcb->pid = pcb_avls;	//use index to define pid
+  pcb->lock_depth = 0;
+
+  pcb->sf = (void *)pcb->p_stack;
+  memcpy(pcb->sf,current->sf,sizeof(struct _RegSet));
+  pcb->time_count = time_chips;
+  pcb->sleep_time = 0;
+
+  pcb->state = READY;
+  strcpy(pcb->name,"PCB1");
+  pcb_avls++;
+  list_add(&(pcb->state_list),&readyq_h);
+  return 0;
+}

apps/nanos/src/kernel/schedule.c

@@ -13,6 +13,7 @@ void schedule() {
     int i;
     for(i = 0; PCBs[i].state_list.next != tmp->next && PCBs[i].state_list.prev != tmp->prev; i++);
     PCB *next = (void *)&(PCBs[i]);
+    printk("next = %s",next->name);
     //fresh new pcb time count
     if(current->pid != 0){
       current->time_count = time_chips;

libs/klib/Makefile

@@ -1,3 +1,3 @@
 NAME = klib
-SRCS = printk.c string.c stdlib.c cpp.c
+SRCS = printk.c string.c stdlib.c cpp.c unistd.c
 include $(AM_HOME)/Makefile.lib

libs/klib/include/klib.h

@@ -51,6 +51,11 @@ int sscanf(const char *str, const char *format, ...);
 
 void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
 
+//unistd.h
+int fork(void);
+void sleep(ulong time);
+void exit(int status);
+
 #define printk printf
 
 // assert.h

libs/klib/unistd.c

@@ -0,0 +1,13 @@
+#include "klib.h"
+
+int fork(void){
+  return _trap(20,0,0,0);
+}
+
+void sleep(ulong time){
+  _trap(21,0,0,0);
+}
+
+void exit(int status){
+  _trap(22,status,0,0);
+}