int
do_open(const char *path, int mode)
{
int fd;
struct file *f;
struct inode *ip;
if ((mode & O_CREATE) &&!(ip =
icreate(path, T_FILE, 0, 0)))
return -1;
else
if (!(ip = namei(path)))
return -1;
if (ip->type == T_DIR && mode != O_RDONLY) {
iput(ip);
return -1;
}
if (!(f = filealloc()) || (fd = fdalloc()) < 0) {
if (f)
fileclose(f);
iput(ip);
return -1;
}
f->type = FD_INODE;
f->ip = ip;
f->off = 0;
f->readable = !(mode & O_WRONLY);
f->writable = (mode & O_WRONLY) || (mode & O_RDWR);
fs_current->ofile[fd] = f;
return fd;
}
int
pipealloc(struct file **f0, struct file **f1) {
struct pipe *p;
p = 0;
*f0 = *f1 = 0;
if ((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0) {
goto bad;
}
if ((p = (struct pipe *)kalloc()) == 0) {
goto bad;
}
p->readopen = 1;
p->writeopen = 1;
p->nwrite = 0;
p->nread = 0;
initlock(&p->lock, "pipe");
(*f0)->type = FD_PIPE;
(*f0)->readable = 1;
(*f0)->writable = 0;
(*f0)->pipe = p;
(*f1)->type = FD_PIPE;
(*f1)->readable = 0;
(*f1)->writable = 1;
(*f1)->pipe = p;
return 0;
//PAGEBREAK: 20
bad:
if (p) {
kfree((char *)p);
}
if (*f0) {
fileclose(*f0);
}
if (*f1) {
fileclose(*f1);
}
return -1;
}
int sys_getcwd()
{
struct inode *ip = idup(current_proc->cwd);
struct file * f = filealloc();
f->in = ip;
f->offset = 0;
f->type = FD_INODE;
f->rw = FD_READABLE;
int fd = fdalloc(f);
if(fd > 0)
return fd;
return -1;
}
int
pipealloc(struct file **f0, struct file **f1)
{
struct pipe *p;
p = 0;
*f0 = *f1 = 0;
if((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0)
goto bad;
if((p = (struct pipe*)kalloc(PAGE)) == 0)
goto bad;
p->readopen = 1;
p->writeopen = 1;
p->writep = 0;
p->readp = 0;
initlock(&p->lock, "pipe");
(*f0)->type = FD_PIPE;
(*f0)->readable = 1;
(*f0)->writable = 0;
(*f0)->pipe = p;
(*f1)->type = FD_PIPE;
(*f1)->readable = 0;
(*f1)->writable = 1;
(*f1)->pipe = p;
return 0;
bad:
if(p)
kfree((char*)p, PAGE);
if(*f0){
(*f0)->type = FD_NONE;
fileclose(*f0);
}
if(*f1){
(*f1)->type = FD_NONE;
fileclose(*f1);
}
return -1;
}
struct file* kernel_open(char* path, int omode){
int fd;
struct file *f;
struct inode *ip;
if(omode & O_CREATE){
begin_trans();
ip = kernel_create(path, T_FILE, 0, 0);
commit_trans();
if(ip == 0)
return 0;
} else {
// cprintf("kernel_open - path is %s\n",path);
if((ip = namei(path)) == 0)
return 0;
//cprintf("kernel_open - path is %s passed namei\n",path);
ilock(ip);
if(ip->type == T_DIR && omode != O_RDONLY){
iunlockput(ip);
return 0;
}
}
// cprintf("kernel_open - before filealloc path %s\n",path);
if((f = filealloc()) == 0 || (fd = kernel_fdalloc(f)) < 0){
if(f)
fileclose(f);
iunlockput(ip);
return 0;
}
iunlock(ip);
f->type = FD_INODE;
f->ip = ip;
f->off = 0;
f->readable = !(omode & O_WRONLY);
f->writable = (omode & O_WRONLY) || (omode & O_RDWR);
return f;
//return fd;
//return 0;
}
/* creates the first process */
void userinit(){
struct proc *p;
/* printf("entered userinit\n"); */
/* allocate memory for stdin wait queue */
_stdin = (struct read_proc*)kmalloc(sizeof(struct read_proc));
memset1((char *)_stdin,0,sizeof(struct read_proc));
memset1((char *)ptable.proc,0,sizeof(ptable));
p=alloc_proc();
initproc=p;
fgproc=initproc;
if(!(p->pml4_t=load_kern_vm())){
/* panic code goes here*/
printf("Kernel Panic: Unable To Create Initproc\n");
}
//inituvm(p->pml4_t,binary_initcode_start,binary_initcode_size);
p->size=FRAME_SIZE;
/* clear the trapframe. this is only done for fist process */
memset1((char *)p->tf,0,sizeof(struct trapframe));
/* p->tf->cs=0x8/\* SEG_KCS() *\/; /\* kernel code segment *\/ */
/* p->tf->ss=0x10/\* SEG_KDS() *\/; /\* kernel data segment *\/ */
p->tf->cs=0x1B; /* user code segment */
p->tf->ss=0x23; /* user data segment */
p->tf->rflags=FL_IF; /* enable interrupts */
/* rsp will be sey in exec */
/* p->tf->rsp=FRAME_SIZE; /\* where does the user stack star from in the proc vm *\/ */
/* rip will be set in exec */
/* p->tf->rip=0; /\* begining of initcode.S *\/ */
strcpy(p->name,"initcode"); /* p->name has a size of 32 bytes */
p->state=RUNNABLE;
/* printf("calling exec\n"); */
/* call exec */
proc=p;
/* set cwd of initproc to root '/' */
strcpy(proc->cwd,"/");
char *a="bin/hello";
char *argv[3];
argv[0]=a;argv[1]="os/sbunix";argv[2]=NULL;
char *envp[7];
envp[0]="PATH=/bin";
envp[1]="envp1";
envp[2]="envp2";
envp[3]="envp3";
envp[4]="envp4";
envp[5]="envp5";
envp[6]=NULL;
cli();
exec("bin/hello",argv,envp);
//p->tf->cs=(SEG_);
/* ltr(0x2Bu); */
/* ltr 0x2B with RPL of 3 for user??? */
ltr(0x2Bu);
/* set WP bit in cr0 */
set_wp_bit();
/* clear ftable */
memset1((char *)ftable.file,0,sizeof(struct file)*NFILE);
/* clear file descriptor table of proc,i.e initproc */
int fd=0;
for(fd=0;fd<NOFILE;fd++){
proc->ofile[fd]=NULL;
}
struct file *fp=NULL;
/* give initproc STDIN, STDOUT,STDERR*/
proc->ofile[STDIN]=filealloc();
if(proc->ofile[STDIN]==NULL){
printf("Kernel Panic, STDIN fiel struct not allocd for initproc\n");
/* panic. kill proc */
}
fp=proc->ofile[STDIN];
fp->type=FD_STDIN;
fp->readable=1; /* mark readable */
fp->writable=0; /* mark not writable */
proc->ofile[STDOUT]=filealloc();
if(proc->ofile[STDOUT]==NULL){
printf("Kernel Panic: STDOUT file struct not allocd for initproc\n");
/* panic. kill proc */
}
fp=proc->ofile[STDOUT];
fp->type=FD_STDOUT;
fp->readable=0; /* mark NOT readable */
fp->writable=1; /* mark writable */
proc->ofile[STDERR]=filealloc();
if(proc->ofile[STDERR]==NULL){
printf("Kernel Panic: STDERR fiel struct not allocd for initproc\n");
/* panic. kill proc */
}
fp=proc->ofile[STDERR];
fp->type=FD_STDERR;
fp->readable=0; /* mark NOT readable */
fp->writable=1; /* mark writable */
/* initialize sleep_head and sleep_tail to NULL */
init_sleep_queue();
init_waitpid_queue();
init_stdin_queue();
/* initialize inodes */
/* init_inodes(); */
/* printf writes to <1MB mem region. Now user page tables are loaded. We cannot access <1MB since we did not map that region into user process < 1MB VM aread */
/* printf("calling scheduler\n"); */
scheduler();
}
